{"title":"Doepfer Filters","description":"","products":[{"product_id":"a-101-2-vactrol-low-pass-gate","title":"Doepfer - A-101-2: Vactrol Low Pass Gate","description":"\u003cp\u003e\u003cb\u003eManufacturer Description\u003c\/b\u003e\u003cspan\u003e:\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eA-101-2 is a vactrol based combination of low pass filter (lp) and vca and was inspired by the buchla module 292. the term \"low pass gate\" was created by don buchla and stands for a module that can be switched between low pass and vca. the control (manually and via external cv) is responsible for frequency in the low pass mode and for loudness in the vca mode. additionally a combined mode lp+vca is available. in this mode the sound becomes more dull as the loudness decreases.\u003c\/span\u003e\u003cbr\u003e\u003cbr\u003e\u003cspan\u003ein contrast to the buchla design the a-101-2 offers attenuators for both cv and audio input, a manual resonance control and two gate inputs to control the function of the module in addition to the manual toggle switch.\u003c\/span\u003e\u003cbr\u003e\u003cbr\u003e\u003cspan\u003ein principle the a-101-2 is a 12 db low pass filter that can be switched to vca or a combination of low pass and vca. the controlling elements for frequency (lp mode) resp. amplitude (vca mode) are so-called vactrols. vactrols are known for their smooth sound behaviour.\u003c\/span\u003e\u003cbr\u003e\u003cbr\u003e\u003cspan\u003ethe frequency (in the lp mode) resp. the amplitude (in the vca mode) is controlled manually (f\/a) and by the 2 control inputs cv1 (without attenuator) and cv2 (with attenuator).\u003c\/span\u003e\u003cbr\u003e\u003cbr\u003e\u003cspan\u003ethe audio input is equipped with an attenuator to enable distortion too (above ~ position 5 distortion is obtained with standard a-100 audio levels, e.g. vco).\u003c\/span\u003e\u003cbr\u003e\u003cbr\u003e\u003cspan\u003ethe resonance function \"colors\" to the sound and is adjustable all the way up to self-oscillation. resonance and consequently self-oscillation may vary with the filter frequency because of vactrol tolerances. due to the circuit the resonance has a little bit an influence on the audio level (increasing resonance = increasing audio level). to obtain the original buchla sound the resonance control simply has to be set fully counterclockwise.\u003c\/span\u003e\u003cbr\u003e\u003cbr\u003e\u003cspan\u003ethe function of the module is controlled by a manual switch. the left and right positions of the switch correspond to lp resp. vca mode. in the middle position one obtains the combination of low pass and vca. in this position it is also possible to control the function of the module by the two gate inputs g1 and g2. the table printed at the front panel shows the connection between the gate levels (l = low, h = high) and the module function.\u003c\/span\u003e\u003cbr\u003e\u003cbr\u003e\u003cspan\u003edue to technical reasons the vactrol modules are not available with blue leds.\u003c\/span\u003e\u003cbr\u003e\u003cbr\u003e\u003cspan\u003ethis module has a maximum current draw of 20ma. it requires 8 te\/hp worth of space to fit in a eurorack frame.\u003c\/span\u003e\u003c\/p\u003e","brand":"Doepfer","offers":[{"title":"Default Title","offer_id":8884387282991,"sku":"","price":127.0,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0020\/5199\/7743\/products\/a-101-2_1ba12584-2820-4f4f-a8c5-3cb4abe44da4.jpg?v=1536180155"},{"product_id":"a-101-6-opto-fet-filter-phaser","title":"Doepfer - A-101-6: Six Stage Opto FET VCF","description":"\u003cp\u003e\u003cb\u003eManufacturer Description\u003c\/b\u003e\u003cspan\u003e:\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eA-101-6 is a new filter module that uses so-called opto fets to control the filter frequency. opto fets are very similar to vactrols but use light depending field effect transistors (fets) instead of light depending resistors (ldrs). a opto fet is a combination of a light depending fet and a led (light emitting diode) both put into a small light-proof case. the advantage compared to vactrols is the much faster response of opto fets compared to ldrs. this allows much faster attack\/decay times and even fm effects. the disadvantage compared to vactrols is that the fet behaves as a normal ohm resistor only for small levels. with higher levels the fet begins to distort. apart from this the notes mentioned on the vactrol basics page are valid.\u003c\/span\u003e\u003cbr\u003e\u003cbr\u003e\u003cspan\u003emodule a-101-6 is made of six serial 6db filter stages. each stage can work as lowpass, highpass or one of two allpass types. \u003c\/span\u003e\u003cbr\u003e\u003cbr\u003e\u003cspan\u003ethe type of filter is chosen by jumpers on the pc board (factory setting: low pass). the type of filter determined by the jumpers positions can be marked by means of a water-resistant felt pen at the front panel. the following document shows the jumper positions for the four different filter types.\u003c\/span\u003e\u003cbr\u003e\u003cbr\u003e\u003cspan\u003ethe resonance is controlled by the feedback control up to self oscillation. by means of a trimming potentiometer the maximal feedback can be adjusted. high feedback values can be used mainly in the allpass mode to obtain very extreme self oscillation sounds. even an external feedback signal can be used instead of the internal feedback connection (fb in socket).\u003c\/span\u003e\u003cbr\u003e\u003cbr\u003e\u003cspan\u003ethe mix control is used to pan between the original signal (ccw position) and the effect signal (cw position). in filter mode (lp\/hp) this control is usually set fully cw. in the allpass modes one obtains phasing sounds at center position or \"pure\" allpass sound in fully cw position.\u003c\/span\u003e\u003cbr\u003e\u003cbr\u003e\u003cspan\u003enote: the originally planned version of the module with voltage controlled switching between the different filter types will be not realized (see front panel sketch at the left side). because of the many required voltage controlled switches this version would have been much more expensive. most of the customers who tried the a-101-6 prototype suggested to leave out this vc switching feature as it was not that impressive and instead manufacture the module in a more affordable version.\u003c\/span\u003e\u003cbr\u003e\u003cbr\u003e\u003cspan\u003eit requires 8 te\/hp worth of space to fit in a eurorack frame.\u003c\/span\u003e\u003c\/p\u003e","brand":"Doepfer","offers":[{"title":"Default Title","offer_id":8884387315759,"sku":"","price":69.0,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0020\/5199\/7743\/products\/a-101-6.jpg?v=1536180195"},{"product_id":"a-106-1-xtreme-lowpass-highpass-filter","title":"Doepfer - A-106-1: Xtreme Lowpass\/Highpass Filter","description":"\u003cp\u003e\u003cb\u003eManufacturer Description\u003c\/b\u003e\u003cspan\u003e:\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eModule a-106-1 has it's origin in our experiments to built a ms20 filter clone. the famous original ms20 included two filters: a 12 db lowpass and a 6db high pass filter connected in series both with a very special design (the ms20 highpass if very often described as 12db high pass, but this is not true). during our researches we found a way to use the same circuit simultaneously as lowpass and highpass for 2 different audio signals (a bit similar to the a-101-1 steiner vactrol filter that has even different audio inputs available, but with the special ms20 circuit). for this two separate audio inputs for lowpass (lp) and highpass (hp) with separate level controls are available. the sockets are normalled, i.e. the signal applied to the lp input is available for the hp input too provided that no plug is inserted into the hp input socket. the level control of the hp input is realized as a polarized input. this means that the signal can be added with the same polarity (+ range) or opposite polarity (- range) compared to the lp input. this feature enables notch (+) and bandpass (-) filter functions too. from our point of view this is the most flexible solution that enables e.g. these functions:\u003c\/span\u003e\u003cbr\u003e\u003cspan\u003e* lowpass: the audio signal is fed to the lp input, hp level control is set to zero, lp level control is set to the desired level\u003c\/span\u003e\u003cbr\u003e\u003cspan\u003e* highpass: the audio signal is fed to the lp or hp input, lp level control is set to zero, hp level control is set to the desired level (in this special case it does not matter if positive or negative amplification is chosen with the polarizer control)\u003c\/span\u003e\u003cbr\u003e\u003cspan\u003e* lowpass\/highpass mix with one audio signal: the audio signal is fed to the lp input, lp and hp level controls are set to the desired levels.\u003c\/span\u003e\u003cbr\u003e\u003cspan\u003e* special setting 1: if the level controls for lp and hp are set in a way that both levels are identical with the same polarity (i.e. + range of the hp level control) and no or little distortion only one obtains ~ a notch filter (the \"~\" indicates that the notch is far from beeing perfect, the attenuation in the passband is not as good as for other filters of the a-100 system)\u003c\/span\u003e\u003cbr\u003e\u003cspan\u003e* special setting 2: if the level controls for lp and hp are set in a way that both levels are identical with the opposite polarity (i.e. - range of the hp level control) and no or little distortion only one obtains ~ a bandpass filter (the \"~\" indicates that even the bandpass is far from beeing perfect, there is a significant feedthrough of frequencies below and above the center frequency.\u003c\/span\u003e\u003cbr\u003e\u003cspan\u003e* remark for settings 1 and 2: the original ms20 circuit was not planned for notch or bandpass applications. the ~notch and ~bandpass filters should be treated as a free bonus and have the disadvantages mentioned above. the reason is that the lowpass has a 12db\/octave slope and the highpass 6db\/octave. this leads to phase relations that do not allow a \"perfect\" bandpass and notch simply by adding\/subtracting signals as for other filter designs (for insiders: there remains always a 90 degree phase shift). for better notches and bandpasses other a-100 filters should be used - or two a-106-1 patched in series (bandpass) or parallel (notch) with suitable frequency settings.\u003c\/span\u003e\u003cbr\u003e\u003cspan\u003e* lowpass and highpass with two different audio signals: the two audio signals are fed to the lp input resp. hp input, the level controls for lp and hp are set to the desired levels. for the +\/- control of the hp input it is essential in this case if the two input signals are phase correlated (e.g. two different outputs of the same vco or vco output and a frequency divided signal derived from this vco) or there is no fixed phase correlation between the two signals (e.g. two different vcos). in the first case the the - and + range of the hp control leads to different filter results. in the second case there is no difference if the + or - range of the hp control is used.\u003c\/span\u003e\u003cbr\u003e\u003cbr\u003e\u003cspan\u003ethis design allows even some very special functions: it is e.g. possible to adjust the controls so that the lp signal does not distort but the hp share does (or the other way round) - alternatively with the same or opposite polarity compared to the lp signal. for this the lp level has to be set to a small value so that the signal does not distort. the hp level control has to be set to a higher value (in the + or - range) so that the hp share will distort.\u003c\/span\u003e\u003cbr\u003e\u003cbr\u003e\u003cspan\u003ethe variety of controls allows a lot of functions that are not available for any other filter we know.\u003c\/span\u003e\u003cbr\u003e\u003cbr\u003e\u003cspan\u003eduring the a-106-1 development we found also that it might be useful to add controls not available in the original ms20 filters. in the original circuit the filter output level is limited to about +\/- 0.7v by two antiparallel diodes across the output\/resonance amplifier. by chance we discovered that removing one or both diodes leads to noticeable different behaviour of the filter. moreover we added two rotary controls cl+ and cl- to adjust the effect of each limiting diode (from original ms20 behaviour, i.e. fully active limiting diodes, to no limiting effect). the independent control for each diode allows asymmetrical limiting\/amplification that causes a completely new and sometimes very strange behaviour. one of the main effects of the asymmetrical limiting is that in self-oscillation the filter does not generate a sine wave but short pulses if only one of the limiting diodes is activated. another effect is that a higher output of the filter can be obtained (limited to about +\/- 0.7v for the original ms20 circuit). in addition dirty noise effects appear at certain combinations of the control settings for resonance, cl+, cl- and input level. the controls cl+, cl-, resonance, lp level and hp level have be looked at always in a common context: if the input levels are small the cl+ and cl- controls will have no effect as the signal does not distort at all. increasing the resonance also increases the audio level and the cl+\/cl- controls may now have an effect without changing the input level! same applies if the resonance control remains unchanged but the input level is increases. now the cl+ or cl- control will have an effect as the level reaches the clipping thresholds. increasing the audio level does also may suppress the resonance if distortion becomes extreme. the \"teamwork\" of the five controls is very complex and has to be learned by doing and hearing\u003c\/span\u003e\u003cbr\u003e\u003cbr\u003e\u003cspan\u003ethe audio inputs are very sensitive to allow even extrem distortion effects, much more than possible for the original ms20.\u003c\/span\u003e\u003cbr\u003e\u003cbr\u003e\u003cspan\u003ewe also expanded the module by an insert option for the resonance feedback loop. this allows to insert other a-100 modules into the resonance circuit. the standard application is to insert a vca for voltage controlled resonance. but even other modules - e.g. waveshaper, divider, phaser, distortion, pll, wave multiplier, spring reverb, ring modulator, frequency shifter ony any other audio processing module - can be inserted to obtain sounds you have never heard before.\u003c\/span\u003e\u003cbr\u003e\u003cbr\u003e\u003cspan\u003eon top of this the module is equipped with two frequency cv inputs. one is carried out as a polarizer. this means that effect of the external cv (e.g. envelope from an adsr a-140 or a-141) to the filter frequency is positive (+ range) or negative (- range). especially when the filter is moved from lp to hp it might be useful to invert the polarity of the envelope cv. we also have to mention that the frequency response if far from 1v\/oct but rather non-linear.\u003c\/span\u003e\u003cbr\u003e\u003cbr\u003e\u003cspan\u003eto obtain the filter section of the original ms20 two a-106-1 have to be patched in series (one in lp mode, the other in hp mode, both with cl+ and cl- set to zero).\u003c\/span\u003e\u003cbr\u003e\u003cbr\u003e\u003cspan\u003eit has to be pointed out that the a-106-1 is far away from beeing a \"perfect\" filter in an academic sense: the control scale is non-linear. with self-oscillation all sorts of waveforms except sine are generated. with high distortion and resonance settings a lot of roaring\/rattling\/noise or other unpredictible sounds may appear. high distortion\/level may \"kill\" the resonance at certain settings. the filter has a significant control voltage feedthrough. the \"bandpass\" is not a real band pass as a considerable share of all frequencies passes through. the notch filter does attenuate only about 50% at the center frequency - and many more. but the a-106-1 has a lot of character - much more than any other filter of the a-100. it is a very strange and awesome filter - somehow exactly the contrast to the a-108, which is a very smooth, warm and predictable filter. the a-106-1 is definitely not the right choice for \"moogish\" and \"civilized\" sounds but for extreme, exceptional and experimental sounds - this is why we call the module \"x-filter\" to avoid troubles with the korg company who is the owner of the term \"ms20\". if you want to know more technical details please look at the a-101-1 technical details. in this document the basics of the a-101-1 (steiner) and a-106-1 (ms20) filters are described.\u003c\/span\u003e\u003cbr\u003e\u003cbr\u003e\u003cspan\u003eincluded options: for the hp input control can be chosen if the polarizer is active or if a normal attenuator is available. for some applications it might be useful to have the level controls of lp and lp work in the same way (e.g. to obtain the same level for both inputs). with a jumper on the pc board the type of hp level control can be chosen. the cl+ and cl- parameters are prepared to be controlled by external vactrols. two pin headers are used to establish a connection to the universal vactrol module that is still under development. this will allow voltage control of the cl+ and cl- parameter.\u003c\/span\u003e\u003cbr\u003e\u003cbr\u003e\u003cspan\u003eapplication ideas:\u003c\/span\u003e\u003cbr\u003e\u003cspan\u003e* using the vc panning module a-134 for voltage control of filter type (audio input -\u0026gt; audio in a-134, left output a-134 -\u0026gt; lp input of a-106-1, right output a-134 -\u0026gt; hp input a-106-1, cv of a-134 controls a-106-1 filter type)\u003c\/span\u003e\u003cbr\u003e\u003cspan\u003e* voltage controlled polarizer a-133 instead of manual control of cv2 or hp level\u003c\/span\u003e\u003cbr\u003e\u003cspan\u003e* different external audio processing modules for the resonance feedback loop.\u003c\/span\u003e\u003cbr\u003e\u003cbr\u003e\u003cspan\u003ethis module has a maximum current draw of 30ma. it requires 14 te\/hp worth of space to fit in a eurorack frame.\u003c\/span\u003e\u003c\/p\u003e","brand":"Doepfer","offers":[{"title":"Default Title","offer_id":8884387348527,"sku":"","price":156.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0020\/5199\/7743\/products\/a-106-1.jpg?v=1536180228"},{"product_id":"a-124","title":"Doepfer - A-124SE (Black \u0026 Yellow)","description":"\u003cp\u003e\u003cspan\u003e\u003cb\u003eManufacturer Description\u003c\/b\u003e:\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003emodule a-124 is a special 12db multimode filter using the \"strange\" filter circuit of the \"edp wasp\" (an analog synthesizer with black\/yellow case built end of the seventies, manufactured by the uk company\"electronic dream plant\"). this design \"abuses\" digital inverters as analog operational amplifiers leading to distortions and other \"dirty\" effects that generate the specific sound of this filter. the filter isequipped with a band pass output and a combined low\/notch\/high pass output. for this output a control knob defines the relation between low and high pass signal. if both signals appear at the same level (i.e.middle position of the mix knob) one obtains a notch filter. otherwise the low or high pass signal predominates. the filter enables no self oscillation in contrast to all other vcfs of the a-100 system.\u003cbr\u003e\u003cbr\u003e\u003cspan\u003einputs: audio in, cv in (2x)\u003cbr\u003eoutputs: bandpass out, low\/highpass mix-out\u003cbr\u003econtrols: audio and cv attenuator, frequency, resonance, lp\/hp mix.\u003cbr\u003e\u003cbr\u003e\u003cspan\u003ethis module has a maximum current draw of 30ma. it requires 8 te\/hp worth of space to fit in a eurorack frame.\u003c\/span\u003e\u003cbr\u003e\u003cbr\u003e\u003cbr\u003e\u003c\/span\u003e\u003c\/span\u003e\u003c\/p\u003e","brand":"Doepfer","offers":[{"title":"Default Title","offer_id":8884422279215,"sku":"","price":115.0,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0020\/5199\/7743\/products\/a-124_wasp_filter.jpg?v=1582334290"},{"product_id":"a-106-5-se","title":"Doepfer - A-106-5SE 12DB SEM Filter Special Edition","description":"\u003cp\u003e\u003cspan\u003e\u003cspan\u003e\u003cb\u003eManufacturer Description\u003c\/b\u003e:\u003c\/span\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003e\u003cspan\u003eModule A-106-5 is a 12dB multimode filter that is based on the filter circuit of the Oberheim SEM module.The filter is equipped with a band pass output and a combined low\/notch\/high pass output. For this output a control knob defines the relation between low and high pass signal. If both signals appear at the same level (i.e. middle position of the Mix knob) one obtains a notch filter. Otherwise the low or high pass signal predominates. The module does not feature self oscillation in contrast to most of the other filters of the A-100 system. The module generates a distorted audio signal if the level control is set to about 50% (i.e. center position) or more with A-100 standard signals like VCOs.\u003cbr\u003e\u003cbr\u003eInputs: Audio In, CV1 In without attenuator, CV2 In with Polarizer\u003cbr\u003eOutputs: Bandpass Out, Low\/Highpass Mix-Out\u003cbr\u003eControls: Audio Attenuator, CV2 Polarizer, Frequency, Resonance, LP\/HP Mix\u003cbr\u003e\u003cbr\u003eThe function and operation of this module is very similar to the Wasp filter module A-124. But the sound of both filters is very different ! We will publish no separate user's manual for the A-106-5 but a combined manual for both A-106-5 and A-124. The only functional difference is the position of the sockets and controls, and the function of the controls CV2 (A-124: normal attenuator, A-106-5: polarizer).\u003cbr\u003e\u003cbr\u003eWidth: 8TE \/ 8HP \/ 40.3 mm\u003cbr\u003eDepth: 55 mm (measured from the rear side of the front panel)\u003cbr\u003eCurrent: +30mA (+12V) \/ -20mA (-12V)\u003cbr\u003e\u003c\/span\u003e\u003c\/span\u003e\u003c\/p\u003e","brand":"Doepfer","offers":[{"title":"Default Title","offer_id":8884422311983,"sku":"","price":127.0,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0020\/5199\/7743\/products\/a-106-5_sem.jpg?v=1536159300"},{"product_id":"a-101-2v","title":"Doepfer - A-101-2V: Vactrol Low Pass Gate","description":"\u003cp\u003e\u003cb\u003eManufacturer Description\u003c\/b\u003e:\u003cbr\u003e\u003cbr\u003eVactrol based combination of resonant 12dB lowpass filter and \/ or VCA. Inspired by Don Buchla.\u003cbr\u003e\u003cbr\u003eDetails\u003cbr\u003e\u003cbr\u003eA Lowpass Gate (LPG) can be a low pass filter, a VCA or a combination of both. This means both the harmonic content and volume can be controlled simultaneously which resembles the behaviour of many instruments: the louder, the more harmonics.\u003cbr\u003e\u003cbr\u003eThe A-101-2's mode of operation is set with a switch: Left position is low pass, right is VCA and the combo mode is in the center. Alternatively you can activate the modes with gate signals which is the reason for two gate inputs; this is very interesting in combination with clock dividers or trigger sequencers.\u003cbr\u003e\u003cbr\u003e Gate 1 high \u0026amp; gate 2 low = Low pass mode\u003cbr\u003e Gate 1 low \u0026amp; gate 2 high = VCA mode\u003cbr\u003e Both Gate 1 \u0026amp; 2 high = Combo mode\u003cbr\u003e\u003cbr\u003eThe A-101-2 has an aggressive sound, compared to other LPGs and it's resonance goes up to self-oscillation which not many LPGs offer. The oscillation is rather dirty and far from being a sine wave .\u003cbr\u003econnectors\u003cbr\u003e\u003cbr\u003eAudio input, audio output\u003cbr\u003eTwo CV inputs, two gate inputs\u003cbr\u003edimensions\u003cbr\u003e\u003cbr\u003e3U Eurorack module, 8 HP wide, 50 mm deep\u003cbr\u003eCurrent draw 20 mA\u003c\/p\u003e","brand":"Doepfer","offers":[{"title":"Default Title","offer_id":8884438859823,"sku":"","price":150.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0020\/5199\/7743\/products\/A-101-2.jpg?v=1536162904"},{"product_id":"a-120v","title":"Doepfer - A-120V: 24dB Low Pass (VCF1)","description":"\u003cp\u003e\u003cb\u003eManufacturer Description\u003c\/b\u003e:\u003c\/p\u003e\n\u003cp\u003e\u003cbr\u003eModule A-120 is a voltage controlled low-pass filter, which filters out the higher parts of the sound spectrum, and lets lower frequencies pass through. The Cut-Off Frequency determines the point at which filtering takes effect. You can control this manually, or by voltage control (filter modulation, for instance by an LFO). Three CV inputs are available, and the sum of the voltages from these affects the filter cut-off.\u003cbr\u003e \u003cbr\u003eThe module is based on a so-called \"transistor ladder\" design, with a cut-off slope of -24 dB\/octave, as in various Moog synthesizers. That's what gives it its classic, legendary Moog sound.Resonance (or Emphasis) is adjustable all the way up to self-oscillation - in which case the filter behaves like a sine wave oscillator.\u003c\/p\u003e","brand":"Doepfer","offers":[{"title":"Default Title","offer_id":8884440465455,"sku":"","price":161.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0020\/5199\/7743\/products\/a120.jpg?v=1536163189"},{"product_id":"doepfer-a-105-4-quad-poly-vcf","title":"Doepfer - A-105-4: Quad Poly VCF","description":"\u003cdiv\u003e\n\u003cstrong\u003eManufacturer Description\u003c\/strong\u003e:\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003eA-105-4 is our first polyphonic filter and contains four identical 24dB Lowpass filters (SSM2044 type). It has available common manual controls and CV inputs with attenuators for these parameters.\u003c\/span\u003e\u003c\/div\u003e\n\u003cdiv\u003e\n\u003cp\u003e\u003cspan\u003eThe module has these controls and in\/outputs are available:\u003c\/span\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eFrequency F \u003c\/span\u003e\u003cspan\u003e (manual control)\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eFrequency Modulation Intensity FM \u003c\/span\u003e\u003cspan\u003e (manual control)\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eResonance Q \u003c\/span\u003e\u003cspan\u003e (manual control)\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eAudio Input Level L \u003c\/span\u003e\u003cspan\u003e (manual control)\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eCVF control (attenuator for Frequency Control Voltage CVF)\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eCVFM control (attenuator for Frequency Modulation Control Voltage VCFM)\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eCVQ control (attenuator for Resonance Control Voltage CVQ)\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eCVL control (attenuator for Level Control Voltage CVL)\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eCVF socket (Frequency Control Voltage CVF)\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eCVFM socket (Frequency Modulation Control Voltage VCFM)\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eCVQ socket (Resonance Control Voltage CVQ)\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eCVL socket (Level Control Voltage CVL)\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eFM Input 1 - 4 \u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eAudio Input 1 - 4\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003cli\u003e\n\u003cp\u003e\u003cspan\u003eAudio Output 1 - 4\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cspan\u003eEach filter has available a separate FM input as well as an Audio Input and Output. The FM input is typically connected to the output of the associated envelope generator (e.g. A-141-4). The envelope amount for all four filters is controlled by the FM knob and the CVFM input by means of four built-in VCAs, which are controlled by the FM control and CVFM input. This allows also voltage control of the envelope amounts. \u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eIn addition common frequency modulation for all filters is possible (e.g. by an LFO). For this the CVF input with attenuator can be used. \u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThe range of the audio input level control (L) allows also clipping\/distortion with typical A-100 audio levels (e.g. from A-111-4) at the filter inputs. Even this parameter is voltage controllable as well as the resonance (Q). \u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eApplication: polyphonic patches (four VCFs with same parameters)\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/div\u003e","brand":"Doepfer","offers":[{"title":"Default Title","offer_id":9838608384047,"sku":"","price":305.0,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0020\/5199\/7743\/products\/A1054.jpg?v=1545177114"},{"product_id":"doepfer-a-123-2-6-12-18-24-db-highpass-filter","title":"Doepfer - A-123-2: 6\/12\/18\/24 dB Highpass Filter","description":"\u003cdiv class=\"description listing-description-readmore readmore-js-section active\" itemprop=\"description\" style=\"height: 730px;\"\u003e\n\u003cdiv\u003e\n\u003cstrong\u003eManufacturer Description\u003c\/strong\u003e:\u003c\/div\u003e\n\u003cdiv\u003e\u003cspan\u003eA-123-2 is a voltage controlled highpass filter with four filter outputs (6, 12, 18 and 24dB slope). It also features voltage control of the resonance.\u003c\/span\u003e\u003c\/div\u003e\n\u003cp\u003e\u003cspan\u003eThese controls and in\/outputs are available:\u003c\/span\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cspan\u003eAudio In with attenuator (Lev)\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003eManual Frequency control (Frq)\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003eFCV1: Frequency control input (~ 1V\/oct)\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003eFCV2: Frequency control input with polarizer\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003eQCV: Resonance control input with attenuator\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003eManual Resonance control (Q)\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003e6dB Output\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003e12dB Output\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003e18dB Output\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan\u003e24dB Output\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cspan\u003e\u003cu\u003eTechnical Notes:\u003c\/u\u003e\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThe module is based on the special circuit CEM3320\/AS3320. In highpass mode this circuit has a cleary higher CV feedthrough than other voltage controlled filters. With high audio levels or slow filter sweeps that's no problem. But with fast changing control voltage (e.g. ADSR with short times or a fast LFO) and low audio levels (i.e. the audio input level is clearly below the level where clipping occurs) a noticeable CV feedthrough may appear at the audio outputs.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eWith typical audio input levels (~10Vpp) from about position 5 of the level control clipping will occur. This is intended to generate distorted signals if desired. If applicable the level control has to be turned back so that no clipped audio signals appear at the outputs.\u003c\/span\u003e\u003c\/p\u003e\n\u003c\/div\u003e","brand":"Doepfer","offers":[{"title":"Default Title","offer_id":9838616117295,"sku":"","price":156.0,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0020\/5199\/7743\/products\/A1232.jpg?v=1545177523"},{"product_id":"doepfer-a-121-3","title":"Doepfer - A-121-3","description":"\u003cp\u003e\u003cspan style=\"font-family: Arial; font-size: small;\" size=\"2\" face=\"Arial\"\u003eModule A-121-3 is functionally nearly identical to module \u003ca href=\"http:\/\/www.doepfer.de\/a1212.htm\"\u003eA-121-2\u003c\/a\u003e. Only the distances between the controls and sockets are smaller and rubberized, small rotary knobs are used. Therefore the front panel width is only 4HP compared to 8HP of the A-121-2. In the first place it is planned for applications where only limited space is available. \u003c\/span\u003e\u003cspan style=\"font-family: Arial; font-size: small;\" size=\"2\" face=\"Arial\"\u003e The only functional difference compared to the A-121-2 is the missing attenuator for the resonance CV input CQ.  \u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan style=\"font-family: Arial; font-size: small;\" size=\"2\" face=\"Arial\"\u003eThese are the most important features of the module:\u003c\/span\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cspan style=\"font-family: Arial; font-size: small;\" size=\"2\" face=\"Arial\"\u003e voltage-controlled multi-mode filter with a cut-off slope of -12 dB \/ octave (idential to the filter \u003c\/span\u003e\u003cspan style=\"font-family: Arial; font-size: small;\" size=\"2\" face=\"Arial\"\u003eof the \u003ca href=\"http:\/\/www.doepfer.de\/Dark_Energy_II_e.htm\"\u003eDark Energy II\/III\u003c\/a\u003e but has been expanded by the voltage controlled resonance feature)\u003c\/span\u003e\n\u003c\/li\u003e\n\u003cli\u003e\u003cspan style=\"font-family: Arial; font-size: small;\" size=\"2\" face=\"Arial\"\u003efour simultaneous outputs are available, each with different characteristics: low-pass (\u003ci\u003eLP\u003c\/i\u003e), high-pass (\u003ci\u003eHP\u003c\/i\u003e), band-pass (\u003ci\u003eBP\u003c\/i\u003e) and notch (\u003ci\u003eN\u003c\/i\u003e) \u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan style=\"font-family: Arial; font-size: small;\" size=\"2\" face=\"Arial\"\u003emanual control \u003ci\u003eFrequ.\u003c\/i\u003e for the cut-off frequency of the filter (the cut-off frequency determines the point at which the respective filter effect appears)\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan style=\"font-family: Arial; font-size: small;\" size=\"2\" face=\"Arial\"\u003etwo inputs for frequency control by means of external control voltages (frequency modulation, e.g. by ADSR or LFO):\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan style=\"font-family: Arial; font-size: small;\" size=\"2\" face=\"Arial\"\u003econtrol voltage input \u003ci\u003eCV1\u003c\/i\u003e without attenuator, about 1V\/octave sensitivity\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan style=\"font-family: Arial; font-size: small;\" size=\"2\" face=\"Arial\"\u003econtrol voltage input \u003ci\u003eCV2\u003c\/i\u003e with attenuator \u003ci\u003eFCV2 \u003c\/i\u003efor the adjustment of the modulation depth of input \u003ci\u003eCV2\u003c\/i\u003e\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan style=\"font-family: Arial; font-size: small;\" size=\"2\" face=\"Arial\"\u003efrequency range about 10Hz ... 20kHz\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan style=\"font-family: Arial; font-size: small;\" size=\"2\" face=\"Arial\"\u003eManual control \u003ci\u003eQ\u003c\/i\u003e for the resonance of the filter\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan style=\"font-family: Arial; font-size: small;\" size=\"2\" face=\"Arial\"\u003econtrol voltage input \u003ci\u003eCQ\u003c\/i\u003e without attenuator for voltage control of the resonance\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan style=\"font-family: Arial; font-size: small;\" size=\"2\" face=\"Arial\"\u003eresonance up to self-oscillation, in which case the module will behave like a sine wave oscillator even without audio input signal\u003c\/span\u003e\u003c\/li\u003e\n\u003cli\u003e\u003cspan style=\"font-family: Arial; font-size: small;\" size=\"2\" face=\"Arial\"\u003eaudio input \u003ci\u003eIn\u003c\/i\u003e with attenuator \u003ci\u003eLevel\u003c\/i\u003e for the adjustment of the filter input level (beyond about pos. 5 clipping\/distortion occurs with typical A-100 audio levels)\u003c\/span\u003e\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Doepfer","offers":[{"title":"Default Title","offer_id":12264346746927,"sku":"","price":127.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0020\/5199\/7743\/products\/doefper_a-121-3.jpg?v=1569493588"},{"product_id":"doepfer-a-106-5-sem-filter","title":"Doepfer - A-106-5 [SEM Filter]","description":"\u003cspan\u003eModule A-106-5 is a \u003cem\u003e\u003cu\u003e12dB multimode filter\u003c\/u\u003e\u003c\/em\u003e that is based on the filter circuit of the Oberheim SEM module.The filter is equipped with a band pass output and a combined low\/notch\/high pass output. For this output a control knob defines the relation between low and high pass signal. If both signals appear at the same level (i.e. middle position of the Mix knob) one obtains a notch filter. Otherwise the low or high pass signal predominates. The module does not feature self oscillation in contrast to most of the other filters of the A-100 system. The module generates a distorted audio signal if the level control is set to about 50% (i.e. center position) or more with A-100 standard signals like VCOs.\u003c\/span\u003e\n\u003cp\u003e\u003cspan\u003eInputs: Audio In, CV1 In without attenuator, CV2 In with Polarizer\u003cbr\u003eOutputs: Bandpass Out, Low\/Highpass Mix-Out\u003cbr\u003eControls: Audio Attenuator, CV2 Polarizer, Frequency, Resonance, LP\/HP Mix\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan\u003eThe function and operation of this module is very similar to the Wasp filter module A-124. But the sound of both filters is very different ! We will publish no separate user's manual for the A-106-5 but a combined manual for both A-106-5 and A-124. The only functional difference is the position of the sockets and controls, and the function of the controls CV2 (A-124: normal attenuator, A-106-5: polarizer)\u003c\/span\u003e\u003c\/p\u003e","brand":"Doepfer","offers":[{"title":"Default Title","offer_id":31404096389184,"sku":"","price":115.0,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0020\/5199\/7743\/products\/doepfer-a-106-5.jpg?v=1580502515"},{"product_id":"doepfer-a-103-tb303","title":"Doepfer - A-103 18dB VCF6","description":"\u003cp data-mce-fragment=\"1\"\u003eModule A-103 is a voltage controlled low pass filter with 18dB\/octave slope.\u003c\/p\u003e\n\u003cp data-mce-fragment=\"1\"\u003eThe circuit is based on a modified transistor ladder (Moog ladder) and is a reproduction of the legendary TB303 filter.\u003c\/p\u003e\n\u003cul data-mce-fragment=\"1\"\u003e\n\u003cli data-mce-fragment=\"1\"\u003emanual control of filter frequency\u003c\/li\u003e\n\u003cli data-mce-fragment=\"1\"\u003e3 CV inputs (CV1, CV2, CV3), 2 of them with attenuator (CV2, CV3)\u003c\/li\u003e\n\u003cli data-mce-fragment=\"1\"\u003einput level control\u003c\/li\u003e\n\u003cli data-mce-fragment=\"1\"\u003eresonance control up to self oscillation\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr class=\"line\" data-mce-fragment=\"1\"\u003e\n\u003cp data-mce-fragment=\"1\"\u003ePower consumption: 30mA at +12V and 10mA at -12V\u003c\/p\u003e\n\u003cp data-mce-fragment=\"1\"\u003eDepth: 55mm\u003c\/p\u003e\n\u003cp\u003eHP : 8\u003c\/p\u003e","brand":"Doepfer","offers":[{"title":"Default Title","offer_id":37703523762346,"sku":"","price":115.0,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0020\/5199\/7743\/products\/A-103.jpg?v=1607369303"},{"product_id":"doepfer-a-102","title":"Doepfer - A-102","description":"\u003cp data-mce-fragment=\"1\"\u003eModule A-102 is a reproduction of the legendary low pass filter design that uses diodes in the filter stage as frequency controlling elements resulting in \"strange\" resonance behaviour and frequency response as resonance and frequency are not independent from another.\u003c\/p\u003e\n\u003cul data-mce-fragment=\"1\"\u003e\n\u003cli data-mce-fragment=\"1\"\u003emanual control of filter frequency\u003c\/li\u003e\n\u003cli data-mce-fragment=\"1\"\u003e3 CV inputs (CV1, CV2, CV3), 2 of them with attenuator (CV2, CV3)\u003c\/li\u003e\n\u003cli data-mce-fragment=\"1\"\u003einput level control\u003c\/li\u003e\n\u003cli data-mce-fragment=\"1\"\u003eresonance control up to self oscillation (depends upon the frequency setting for the A-102)\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003chr class=\"line\" data-mce-fragment=\"1\"\u003e\n\u003cp data-mce-fragment=\"1\"\u003ePower consumption: 30mA at +12V and 10mA at -12V\u003c\/p\u003e\n\u003cp data-mce-fragment=\"1\"\u003eDepth: 60mm\u003c\/p\u003e\nHP : 8","brand":"Doepfer","offers":[{"title":"Default Title","offer_id":37703539196074,"sku":"","price":60.0,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0020\/5199\/7743\/products\/A-102.jpg?v=1607369574"},{"product_id":"doepfer-a-101-1","title":"Doepfer - A-101-1","description":"\u003cp data-mce-fragment=\"1\"\u003eThis is the first vactrol based module in the A-100 system.\u003c\/p\u003e\n\u003cp data-mce-fragment=\"1\"\u003eA vactrol is a combination of a light depending resistor (LDR) and a LED (light emitting diode) both put into a small light-proof case. Increasing the LED brightness causes a decrease of the LDR resistance (e.g. the light controlled voltage module A-179 is an application of a LDR). This effect can be used in circuits that require variable resistors to obtain the desired function (e.g. VCFs, VCAs, VC phasers, VC trigger delays, VC slew limiters, VC Envelope Generators, VC LFOs, VCOs and many more). The advantage of vactrols compared with other solutions (e.g. OTAs, diodes, transistors or FETs as variable resistors) is that they behave like a normal Ohm resistor and can handle high voltages without causing distortion. This is probably the reason why the sound of vactrol-based circuits usually is described as soft or mellow. Disadvantages are the expenditure and consequently the expenses and the not exactly defined coherence between LED current and LDR resistance. For each vactrol the LDR resistance decreases when the LED current increases but mechanical and electrical tolerances cause that each vactrol will behave a bit different (e.g. because of the differences in alignement and distance between LED and LDR, different brightness of the LEDs at the same current).\u003c\/p\u003e\n\u003cp data-mce-fragment=\"1\"\u003eModule A-101-1 is a special multitype filter based on an idea by Nyle A. Steiner. The circuit uses the standard non-inverting amplifier filter design. Different filter types (low pass \/ LP, band pass \/ BP, high pass \/ HP) are realized by injecting the audio signal into different points of the circuit and using a common output for all filter types. One may feed three different audio signals into the filter simultaneously. Each signal is filtered correspondingly (LP resp. BP resp. HP) and the sum of the three filtered signals appears at the output. Of course it is possible to feed the same signal to all three inputs. In this case one obtains different combinations of LP\/BP\/HP according to the settings of the three input attenuators for LP\/BP\/HP. Even a Notch filter is possible (not available in the original design). The filter inputs are normalled, i.e. the BP input is connected to the LP jack socket provided that no cable is plugged into the BP socket (same applies for HP\/BP inputs).\u003c\/p\u003e\n\u003cp data-mce-fragment=\"1\"\u003eIn contrast to the original circuit vactrols are used instead of diodes as variable resistors for frequency control of the filter. Due to the\"crooked\" response of vactrols the filter has not an exact frequency control standard (like V\/Oct). The inevitable tolerances between different vactrols will lead to an individual sound of each module and individual resonance behaviour. Even the resonance control is realized with vactrols. Consequently this parameter is voltage controlled, too. Resonance can be increased up to self-oscillation. Resonance and consequently self-oscillation may vary with the filter frequency because of vactrol tolerances.\u003c\/p\u003e\n\u003cp data-mce-fragment=\"1\"\u003eA special feature of the module are the two audio outputs. Out 1 is the output of the original circuit. In the original circuit by Nyle A. Steiner the output level was distinctly dependent upon the resonance (higher resonance = higher output level). Out 2 compensates this behaviour by the usage of an additional vactrol that is connected in series to the vactrol that controls the resonance. This additional vactrol forms an attenuator (or simple VCA) that approximately compensates the level increase for higher resonance settings.\u003c\/p\u003e\n\u003chr class=\"line\" data-mce-fragment=\"1\"\u003e\n\u003cp data-mce-fragment=\"1\"\u003ePower consumption: 30mA at +12V and 30mA at -12V\u003c\/p\u003e\n\u003cp data-mce-fragment=\"1\"\u003eDepth: 50mm\u003c\/p\u003e\nHP : 16","brand":"Doepfer","offers":[{"title":"Default Title","offer_id":37703579304106,"sku":"","price":184.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0020\/5199\/7743\/products\/A-101-1.jpg?v=1607370419"},{"product_id":"doepfer-a-104","title":"Doepfer - A-104","description":"\u003cp data-mce-fragment=\"1\"\u003eA-104 is a fourfold formant filter as used in the Mixtur Trautonium by Oskar Sala.\u003c\/p\u003e\n\u003cp data-mce-fragment=\"1\"\u003eIt is made of four parallel resonance filters, each filter can be switched to low pass or band pass or off. Frequency, resonance and level are controlled for each filter separately (no voltage control). The frequency range for the filters is about 50Hz...5kHz. The filter audio inputs are very sensitive so that distortion may intentionally be used to create new sounds - if desired. The A-104 is a versatile module for sound modification.\u003c\/p\u003e\n\u003cp data-mce-fragment=\"1\"\u003eIn the first place it is used for reproduction of resonances (e.g. the vocal-like effects known from the Trautonium). In combination with the subharmonic generator A-113, the Trautonium Manual A-198 and some other A-100 modules one obtains a Trautonium replica.\u003c\/p\u003e\n\u003chr class=\"line\" data-mce-fragment=\"1\"\u003e\n\u003cp data-mce-fragment=\"1\"\u003ePower consumption: 30mA at +12V and 10mA at -12V\u003c\/p\u003e\n\u003cp data-mce-fragment=\"1\"\u003eDepth: 45mm\u003c\/p\u003e\nHP : 20","brand":"Doepfer","offers":[{"title":"Default Title","offer_id":37703584186538,"sku":"","price":190.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0020\/5199\/7743\/products\/A-104.jpg?v=1607370672"},{"product_id":"doepfer-a-108","title":"Doepfer - A-108","description":"\u003cp\u003eModule A-108 is a completely new voltage-controlled low pass pass filter based on the well-known transistor ladder (Moog ladder).\u003c\/p\u003e\n\u003cp\u003eThe module has internally an 8 stage low pass filter with different slopes available: 6, 12, 18, 24, 30, 36, 42 and 48 dB per octave. In addition it features an band pass output (i.e. band pass with transistor ladder). In the factory the 4 low pass outputs of the A-108 are internally connected to the filter stages 6, 12, 24 and 48dB. From our first A-108 audio tests this seems to be the best output combination as these outputs generate audible different sounds. E.g. the audible difference between the 48dB and 42dB or between 42dB and 36dB is very little. But if desired any of the filter stages can be connected to one of the outputs.\u003c\/p\u003e\n\u003cp\u003eRemark: Only 4 output stages are available as this seems to be sufficient from our experiences. In the factory the out stages are connected to the filter stages with 6, 12, 24 and 48 dB slope. By changing the internal connections (jumpers or wires) each of the filter stages can be used but only four at a time. Even a multi-way switch could be used but from our results the factory setting (6\/12\/24\/48dB) is the best combination for musical applications. From our experience it would e.g. make not much sense to have 30dB, 36dB, 42dB and 48dB available simultaneously - but if desired one could have this combination avaiable.\u003c\/p\u003e\n\u003cp\u003eResonance (Emphasis or Q ) can be adjusted manually right up to self-oscillation, in which case the filter will behave like a sine wave oscillator. The A-108 features an external feedback input that enables the insertion of additinal modules into the feedback path (e.g. VCA for voltage controlled resonance or phaser\/frequency shifter for phase\/frequency shifting effects). The socket is normalized and internally connected to the 48dB low pass output if no cable is inserted into the feedback socket. The frequency can be adjusted manually, or by voltage control. Three CV inputs (CV1, CV2, CV3) are available. CV2 and CV3 are eqipped with attenuators.\u003c\/p\u003e\n\u003cp\u003eThe filter audio input is very sensitive so that distortion - if desired - is possible even with normal A-100 levels (e.g. VCO output). Self oscillation will break off at high distortion levels as the internal feedback signal is drown out by the distorted audio signal. This feature may intentionally be used to create new sounds. In combination with the Voltage Controlled Mixer A-135 and the Morphing Controller A-144 a filter with voltage controlled slope can be realized (i.e. controlling the slope from 6dB to 48dB via CV).\u003c\/p\u003e\n\u003chr class=\"line\"\u003e\n\u003cp\u003ePower consumption: 40mA at +12V and 40mA at -12V\u003c\/p\u003e\n\u003cp\u003eDepth: 75mm\u003c\/p\u003e\n\u003cp\u003eHP : 12\u003c\/p\u003e","brand":"Doepfer","offers":[{"title":"Default Title","offer_id":37703610237098,"sku":"","price":207.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0020\/5199\/7743\/products\/A-108.jpg?v=1607371148"},{"product_id":"doepfer-a-106-6v-xp-filter","title":"Doepfer - A-106-6V XP Filter","description":"\u003cp data-mce-fragment=\"1\"\u003eModule A-106-6V is a multimode filter that is based on the filter circuit of the Oberheim Xpander. The module features 15 different filter types with 8 filters available simultaneously.\u003c\/p\u003e\n\u003cp data-mce-fragment=\"1\"\u003eThe toggle switch Filter Group is used to switch between 2 filter groups. These filter types are available:\u003c\/p\u003e\n\u003cul data-mce-fragment=\"1\"\u003e\n\u003cli data-mce-fragment=\"1\"\u003e1L (6 dB low pass)\u003c\/li\u003e\n\u003cli data-mce-fragment=\"1\"\u003e2L (12 dB low pass)\u003c\/li\u003e\n\u003cli data-mce-fragment=\"1\"\u003e3L (18 dB low pass)\u003c\/li\u003e\n\u003cli data-mce-fragment=\"1\"\u003e4L (24 dB low pass)\u003c\/li\u003e\n\u003cli data-mce-fragment=\"1\"\u003e1H (6 dB high pass)\u003c\/li\u003e\n\u003cli data-mce-fragment=\"1\"\u003e2H (12 dB high pass)\u003c\/li\u003e\n\u003cli data-mce-fragment=\"1\"\u003e3H (18 dB high pass)\u003c\/li\u003e\n\u003cli data-mce-fragment=\"1\"\u003e2B (6 dB band pass)\u003c\/li\u003e\n\u003cli data-mce-fragment=\"1\"\u003e4B (12 dB bandpass)\u003c\/li\u003e\n\u003cli data-mce-fragment=\"1\"\u003e2N (notch)\u003c\/li\u003e\n\u003cli data-mce-fragment=\"1\"\u003e3A (allpass)\u003c\/li\u003e\n\u003cli data-mce-fragment=\"1\"\u003e2H1L (asymmetrical band pass made of a 12 dB high pass and a 6 dB low pass)\u003c\/li\u003e\n\u003cli data-mce-fragment=\"1\"\u003e3H1L (asymmetrical band pass made of a 18 dB high pass and a 6 dB low pass)\u003c\/li\u003e\n\u003cli data-mce-fragment=\"1\"\u003e2N1L (combination of notch and 6 dB low pass)\u003c\/li\u003e\n\u003cli data-mce-fragment=\"1\"\u003e3A1L (combination of allpass and 6 dB low pass)\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-mce-fragment=\"1\"\u003eThe module features voltage controlled resonance. For filter group 2 (2L, 4L, 2B ...) even self oscillation is possible. All standard VCF controls are available: manual filter frequency control Frq, one control voltage input with attenuator (FCV2)and one without attenuator (FCV1, ~ 1 V\/octave). In addition voltage controlled resonance with manual control (Q) and a CV input with attenuator (QCV) are available. The circuit is based on a 24dB lowpass filter. The outputs of the four internal filter stages (i.e. the 6, 12, 18 and 24dB outputs) are mixed together with different levels and polarities to obtain 15 different filters. Because of this special circuit the outputs have slightly different levels and noise floor. This is caused by the different internal amplifications and numbers of stages that are required to generate the filter in question. If e.g. a filter is derived by one stage only (e.g. the 6 dB, 12dB, 18dB and 24dB low pass) the noise floor is smaller compared to a filter that is derived by a combination of all four filter stages. The module generates a distorted audio signal if the level control is set to about 50% (i.e. center position) or more with A-100 standard signals like VCOs.\u003c\/p\u003e\n\u003chr class=\"line\" data-mce-fragment=\"1\"\u003e\n\u003cp data-mce-fragment=\"1\"\u003ePower consumption: 50mA at +12V and 50mA at -12V\u003c\/p\u003e\n\u003cp data-mce-fragment=\"1\"\u003eDepth: 50mm\u003c\/p\u003e\nHP : 12","brand":"Doepfer","offers":[{"title":"Default Title","offer_id":37994669801642,"sku":"","price":225.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0020\/5199\/7743\/products\/a-106-6v.jpg?v=1612554110"},{"product_id":"doepfer-a-101-1v","title":"Doepfer - A-101-1V","description":"\u003cp data-mce-fragment=\"1\"\u003eThis is the first vactrol based module in the A-100 system.\u003c\/p\u003e\n\u003cp data-mce-fragment=\"1\"\u003eA vactrol is a combination of a light depending resistor (LDR) and a LED (light emitting diode) both put into a small light-proof case. Increasing the LED brightness causes a decrease of the LDR resistance (e.g. the light controlled voltage module A-179 is an application of a LDR). This effect can be used in circuits that require variable resistors to obtain the desired function (e.g. VCFs, VCAs, VC phasers, VC trigger delays, VC slew limiters, VC Envelope Generators, VC LFOs, VCOs and many more). The advantage of vactrols compared with other solutions (e.g. OTAs, diodes, transistors or FETs as variable resistors) is that they behave like a normal Ohm resistor and can handle high voltages without causing distortion. This is probably the reason why the sound of vactrol-based circuits usually is described as soft or mellow. Disadvantages are the expenditure and consequently the expenses and the not exactly defined coherence between LED current and LDR resistance.\u003c\/p\u003e\n\u003cp data-mce-fragment=\"1\"\u003eFor each vactrol the LDR resistance decreases when the LED current increases but mechanical and electrical tolerances cause that each vactrol will behave a bit different (e.g. because of the differences in alignement and distance between LED and LDR, different brightness of the LEDs at the same current).\u003c\/p\u003e\n\u003cp data-mce-fragment=\"1\"\u003eModule A-101-1 is a special multitype filter based on an idea by Nyle A. Steiner. The circuit uses the standard non-inverting amplifier filter design. Different filter types (low pass \/ LP, band pass \/ BP, high pass \/ HP) are realized by injecting the audio signal into different points of the circuit and using a common output for all filter types. One may feed three different audio signals into the filter simultaneously. Each signal is filtered correspondingly (LP resp. BP resp. HP) and the sum of the three filtered signals appears at the output. Of course it is possible to feed the same signal to all three inputs. In this case one obtains different combinations of LP\/BP\/HP according to the settings of the three input attenuators for LP\/BP\/HP. Even a Notch filter is possible (not available in the original design). The filter inputs are normalled, i.e. the BP input is connected to the LP jack socket provided that no cable is plugged into the BP socket (same applies for HP\/BP inputs).\u003c\/p\u003e\n\u003cp data-mce-fragment=\"1\"\u003eIn contrast to the original circuit vactrols are used instead of diodes as variable resistors for frequency control of the filter. Due to the\"crooked\" response of vactrols the filter has not an exact frequency control standard (like V\/Oct). The inevitable tolerances between different vactrols will lead to an individual sound of each module and individual resonance behaviour. Even the resonance control is realized with vactrols. Consequently this parameter is voltage controlled, too. Resonance can be increased up to self-oscillation. Resonance and consequently self-oscillation may vary with the filter frequency because of vactrol tolerances.\u003c\/p\u003e\n\u003cp data-mce-fragment=\"1\"\u003eA special feature of the module are the two audio outputs. Out 1 is the output of the original circuit. In the original circuit by Nyle A. Steiner the output level was distinctly dependent upon the resonance (higher resonance = higher output level). Out 2 compensates this behaviour by the usage of an additional vactrol that is connected in series to the vactrol that controls the resonance. This additional vactrol forms an attenuator (or simple VCA) that approximately compensates the level increase for higher resonance settings.\u003c\/p\u003e\n\u003chr class=\"line\" data-mce-fragment=\"1\"\u003e\n\u003cp data-mce-fragment=\"1\"\u003ePower consumption: 30mA at +12V and 30mA at -12V\u003c\/p\u003e\n\u003cp data-mce-fragment=\"1\"\u003eDepth: 50mm\u003c\/p\u003e\nHP : 16","brand":"Doepfer","offers":[{"title":"Default Title","offer_id":39706165018794,"sku":"","price":207.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0020\/5199\/7743\/products\/a-101-1v.jpg?v=1619034690"},{"product_id":"doepfer-a-121-2-multimode-filter","title":"Doepfer - A-121-2 Multimode Filter","description":"\u003cp data-mce-fragment=\"1\"\u003eModule A-121-2 is a voltage-controlled multi-mode filter with a cut-off slope of -12 dB \/ octave.\u003c\/p\u003e\n\u003cp data-mce-fragment=\"1\"\u003eFour simultaneous outputs are available, each with different characteristics: low-pass, band-pass, high-pass and notch (or band reject). The cut-off frequency determines the point at which the respective filter effects appear. The frequency can be adjusted manually, or by voltage control (Filter modulation, for instance by an LFO or ADSR). Two CV inputs are available, whose control voltages are summed. Resonance (Emphasis or Q ) can be adjusted manually, or by voltage control (voltage-controlled resonance \/ VCQ), right up to self-oscillation, in which case it will behave like a sine wave oscillator.\u003c\/p\u003e\n\u003chr class=\"line\" data-mce-fragment=\"1\"\u003e\n\u003cp data-mce-fragment=\"1\"\u003ePower consumption: 40mA at +12 V and 40mA at -12 V\u003c\/p\u003e\n\u003cp data-mce-fragment=\"1\"\u003eDepth: 50mm\u003c\/p\u003e\nHP : 8","brand":"Doepfer","offers":[{"title":"Default Title","offer_id":41399110762666,"sku":"","price":156.0,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0020\/5199\/7743\/products\/a-121-2.jpg?v=1632168127"},{"product_id":"doepfer-a-120-24db-low-pass-1","title":"Doepfer - A-120 24dB Low Pass 1","description":"\u003cp data-mce-fragment=\"1\"\u003eModule A-120 is a voltage controlled low-pass filter, which filters out the higher parts of the sound spectrum, and lets lower frequencies pass through. The Cut-Off Frequency determines the point at which filtering takes effect. You can control this manually, or by voltage control (filter modulation, for instance by an LFO). Three CV inputs are available, and the sum of the voltages from these affects the filter cut-off. VCF1 is a co-called \"transistor ladder\" design, with a cut-off slope of -24 dB\/octave, as in various Moog synthesizers. That's what gives it its classic, legendary Moog sound. Resonance (or Emphasis) is adjustable all the way up to self-oscillation - in which case the filter behaves like a sine wave oscillator.\u003c\/p\u003e\n\u003chr class=\"line\" data-mce-fragment=\"1\"\u003e\n\u003cp data-mce-fragment=\"1\"\u003ePower consumption: 30mA at +12V and 20mA at -12V\u003c\/p\u003e\n\u003cp data-mce-fragment=\"1\"\u003eDepth: 65mm\u003c\/p\u003e\n\u003cp\u003eHP : 8\u003c\/p\u003e","brand":"Doepfer","offers":[{"title":"Default Title","offer_id":42529564065962,"sku":"","price":138.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0020\/5199\/7743\/products\/1000159_1.jpg?v=1644628491"},{"product_id":"doepfer-a-121s","title":"Doepfer - A-121s","description":"\u003cp\u003e\u003ciframe width=\"560\" height=\"315\" src=\"https:\/\/www.youtube.com\/embed\/N3IESj6r7nI\" title=\"YouTube video player\"\u003e\u003c\/iframe\u003e\u003c\/p\u003e\n\u003cp\u003eModule A-121s is a dual multimode filter which can be used for stereo applications as well as for parallel or serial organized dual mono filters. The core is a 12dB multimode filter identical to the modules A-121-2 and A-121-3. The selection of the filter type is continuously from lowpass via notch and highpass to bandpass. We attached great importance to the usability of the manual controls and CV inputs for both stereo and dual mono applications. For the filter parameters frequency (F), resonance (Q) and type (T) common controls and CV inputs as well as single controls and CV inputs are available. For the filter frequency in addition a manual control and CV input for the filter spread (frequency difference or delta F) is available.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eControls:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eF\u003c\/strong\u003e: master frequency control for both filters (large knob)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eType 1 \/ Type 2\u003c\/strong\u003e: filter type panning\/morphing L-N-H-B\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e Link to 1\u003c\/strong\u003e: Toggle switch so that Type 1 also controls type of filter 2 (i.e. simultaneous filter type control for both filters)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSFM1 \/ SFM2\u003c\/strong\u003e: Single Frequency Modulation controls (polarizers), connected to the corresponding sockets SFM1\/SFM2 (socket SFM1 is normalled to a fixed positive voltage, SFM2 is normalled to SFM1, that way the controls SFM1\/SFM2 work as frequency controls for each filter provided that no modulation signals are patched to the SFM1\/SFM2 sockets)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCFM\u003c\/strong\u003e: common frequency control, controls two VC-polarizers which process the signals connected to the two sockets CFM1\/CFM2, CFM2 is normalled to CFM1, that way also the same modulation signal (e.g. an envelope generator) can be used for both filters and the level controlled simultaneously by the CFM control\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e Delta F\u003c\/strong\u003e: controls the difference between the frequencies of the two filters manually (frequency \"spread\"), at center position the frequencies are the same\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e Delta FM\u003c\/strong\u003e: controls the level of the Delta FM signal (socket), which allows to control the spread between the frequencies also by an external control voltage (e.g. by an LFO or ADSR)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eQ\u003c\/strong\u003e: controls the resonance of both filters simultaneously\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e Level 1 \/ Level 2\u003c\/strong\u003e: attenuators for the two audio inputs\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e QM\/TM1, QM\/TM2\u003c\/strong\u003e: attenuators for the modulation inputs QM\/TM1 and QM\/TM2 \u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003e\u003cstrong\u003eSockets:\u003cbr\u003e\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eIn1 \/ In2\u003c\/strong\u003e: audio inputs (In2 is normalled to In1)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eOut1 \/ Out2\u003c\/strong\u003e: audio outputs\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eF\u003c\/strong\u003e: common frequency control input for both filters (~ 1V\/oct)\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e Delta FM\u003c\/strong\u003e: Control voltage for frequency spread, processed by the polarizer Delta FM\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSFM1 \/ SFM2\u003c\/strong\u003e: single frequency modulation inputs, processed by the polarizers SFM1 and SFM2,  SFM1 is normalled to a fixed positive voltage, SFM2 is normalled to SFM1#\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eCFM1 \/ CFM2\u003c\/strong\u003e: common frequency modulation inputs, processed by the two voltage controlled polarizers controlled by CFM knob, CFM2 is normalled to CFM1\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003e QM\/TM1, QM\/TM2\u003c\/strong\u003e: the addressing of these sockets\/attenuators is defined by internal jumpers. QM means Q modulation (i.e. resonance modulation), TM means filter type modulation (QM1 = resonance modulation filter 1, QM2 = resonance modulation filter 2, TM1 = filter type modulation filter 1, TM2 = filter type modulation filter 2), socket QM\/TM1 is normalled to a fixed positive voltage, QM\/TM2 is normalled to QM\/TM1\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eA 45 degrees triangle next to a socket means that the switching contact of the socket is normalled to a fixed positive voltage (SFM1, QM\/TM1).\u003cbr\u003eA vertical triangle indicates the normalling of two sockets (In1\u0026gt;In2, SFM1\u0026gt;SFM2, CFM1\u0026gt;CFM2, QM\/TM1\u0026gt;QM\/TM2).\u003c\/p\u003e\n\u003cp\u003eIf the filters do not behave as expected please pay attention to these peculiarities:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eFor the controls \u003cstrong\u003eSFM1, SFM2, CFM, Delta F\u003c\/strong\u003e and\u003cstrong\u003e Delta FM\u003c\/strong\u003e the \u003cu\u003ecenter position is the neutral position\u003c\/u\u003e as these are polarizers. If the filter behaves unexpected these controls should be set to center positions for the time beeing. \u003c\/li\u003e\n\u003cli\u003eIn addition the sockets \u003cstrong\u003eSFM1 \u003c\/strong\u003e and\u003cstrong\u003e SFM2\u003c\/strong\u003e are normalled to fixed positive voltages provided that no patch cables are inserted into these sockets. In this case the controls \u003cstrong\u003eSFM1\u003c\/strong\u003e and \u003cstrong\u003eSFM2\u003c\/strong\u003e work as additional individual manual controls for the frequencies of filter 1 and 2 with center positions as neutral positions.\u003c\/li\u003e\n\u003cli\u003eFor the controls \u003cstrong\u003eF, Q, Level 1, Level 2, QM\/TM1\u003c\/strong\u003e und\u003cstrong\u003e QM\/TM2\u003c\/strong\u003e the \u003cu\u003e fully CCW position is the neutral position\u003c\/u\u003e as these are standard attenuators. If the filter behaves unexpected at least the controls \u003cstrong\u003eQM\/TM1\u003c\/strong\u003e and\u003cstrong\u003e QM\/TM2\u003c\/strong\u003e should be set to fully CCW. The reason is that via the normalling of the sockets \u003cstrong\u003eQM\/TM1\u003c\/strong\u003e and \u003cstrong\u003eQM\/TM2\u003c\/strong\u003e the associated controls generate control voltages which are added to the control voltages generated by the main contols (Type 1, Typ 2, Q). Which of these parameters are affected depends upon the settings of the internal jumpers. \u003cbr\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp\u003eBy means of small circles at the bottom right side of the front panel the user can mark the function of the QM\/TM inputs. These assignments are possible:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eQM\/TM1\u003c\/strong\u003e controls QM1, \u003cstrong\u003eQM\/TM2\u003c\/strong\u003e controls QM2, the filter types are not controlled by external CVs\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eQM\/TM1\u003c\/strong\u003e controls TM1, \u003cstrong\u003eQM\/TM2\u003c\/strong\u003e controls TM2, the resonances are not controlled by external CVs\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eQM\/TM1\u003c\/strong\u003e controls QM1 and QM2 simultaneously, \u003cstrong\u003eQM\/TM2\u003c\/strong\u003e controls TM1 and TM2 simultaneously\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul\u003e\n\u003cli\u003e\u003cstrong\u003eApplications:\u003c\/strong\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul\u003e\n\u003cli\u003e\n\u003cstrong\u003eStereo filter\u003c\/strong\u003e: two different audio signals are connected to the audio inputs. At the outputs appear the filtered signals. The filterings depend upon the positions of the manual controls and the applied control voltages.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eSerial mono filter:\u003c\/strong\u003e the mono signal is applied to audio input 1. Audio output 1 is connected to audio input 2. The filtered mono signal appears at audio output 2. One has to pay attention that the filter parameters are set in a way so that a signal will appear at the output. If for example a lowpass and a highpass are daisy chained the frequency of the lowpass has to be higher than the frequency of the highpass. Otherwise no signal will appear at the output.\u003c\/li\u003e\n\u003cli\u003e\n\u003cstrong\u003eParallel mono filter:\u003c\/strong\u003e the audio signal is fed to both audio inputs (e.g. via the normalled sockets In1\u0026gt;In2). By means of a mixer module the audio outputs 1 and 2 are mixed.\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Doepfer","offers":[{"title":"Default Title","offer_id":43496969863338,"sku":"","price":165.0,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0020\/5199\/7743\/products\/doepfer_a-121-s_01.jpg?v=1663895619"},{"product_id":"doepfer-a-121sv","title":"Doepfer - A-121sV","description":"\u003ciframe width=\"560\" height=\"315\" src=\"https:\/\/www.youtube.com\/embed\/N3IESj6r7nI\" title=\"YouTube video player\" frameborder=\"0\" allow=\"accelerometer; autoplay; clipboard-write; encrypted-media; gyroscope; picture-in-picture\" allowfullscreen\u003e\u003c\/iframe\u003e\u003cp data-mce-fragment=\"1\"\u003eModule A-121s is a dual multimode filter which can be used for stereo applications as well as for parallel or serial organized dual mono filters. The core is a 12dB multimode filter identical to the modules A-121-2 and A-121-3. The selection of the filter type is continuously from lowpass via notch and highpass to bandpass. We attached great importance to the usability of the manual controls and CV inputs for both stereo and dual mono applications. For the filter parameters frequency (F), resonance (Q) and type (T) common controls and CV inputs as well as single controls and CV inputs are available. For the filter frequency in addition a manual control and CV input for the filter spread (frequency difference or delta F) is available.\u003c\/p\u003e\n\u003cp data-mce-fragment=\"1\"\u003e\u003cstrong data-mce-fragment=\"1\"\u003eControls:\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul data-mce-fragment=\"1\"\u003e\n\u003cli data-mce-fragment=\"1\"\u003e\n\u003cstrong data-mce-fragment=\"1\"\u003eF\u003c\/strong\u003e: master frequency control for both filters (large knob)\u003c\/li\u003e\n\u003cli data-mce-fragment=\"1\"\u003e\n\u003cstrong data-mce-fragment=\"1\"\u003eType 1 \/ Type 2\u003c\/strong\u003e: filter type panning\/morphing L-N-H-B\u003c\/li\u003e\n\u003cli data-mce-fragment=\"1\"\u003e\n\u003cstrong data-mce-fragment=\"1\"\u003e Link to 1\u003c\/strong\u003e: Toggle switch so that Type 1 also controls type of filter 2 (i.e. simultaneous filter type control for both filters)\u003c\/li\u003e\n\u003cli data-mce-fragment=\"1\"\u003e\n\u003cstrong data-mce-fragment=\"1\"\u003eSFM1 \/ SFM2\u003c\/strong\u003e: Single Frequency Modulation controls (polarizers), connected to the corresponding sockets SFM1\/SFM2 (socket SFM1 is normalled to a fixed positive voltage, SFM2 is normalled to SFM1, that way the controls SFM1\/SFM2 work as frequency controls for each filter provided that no modulation signals are patched to the SFM1\/SFM2 sockets)\u003c\/li\u003e\n\u003cli data-mce-fragment=\"1\"\u003e\n\u003cstrong data-mce-fragment=\"1\"\u003eCFM\u003c\/strong\u003e: common frequency control, controls two VC-polarizers which process the signals connected to the two sockets CFM1\/CFM2, CFM2 is normalled to CFM1, that way also the same modulation signal (e.g. an envelope generator) can be used for both filters and the level controlled simultaneously by the CFM control\u003c\/li\u003e\n\u003cli data-mce-fragment=\"1\"\u003e\n\u003cstrong data-mce-fragment=\"1\"\u003e Delta F\u003c\/strong\u003e: controls the difference between the frequencies of the two filters manually (frequency \"spread\"), at center position the frequencies are the same\u003c\/li\u003e\n\u003cli data-mce-fragment=\"1\"\u003e\n\u003cstrong data-mce-fragment=\"1\"\u003e Delta FM\u003c\/strong\u003e: controls the level of the Delta FM signal (socket), which allows to control the spread between the frequencies also by an external control voltage (e.g. by an LFO or ADSR)\u003c\/li\u003e\n\u003cli data-mce-fragment=\"1\"\u003e\n\u003cstrong data-mce-fragment=\"1\"\u003eQ\u003c\/strong\u003e: controls the resonance of both filters simultaneously\u003c\/li\u003e\n\u003cli data-mce-fragment=\"1\"\u003e\n\u003cstrong data-mce-fragment=\"1\"\u003e Level 1 \/ Level 2\u003c\/strong\u003e: attenuators for the two audio inputs\u003c\/li\u003e\n\u003cli data-mce-fragment=\"1\"\u003e\n\u003cstrong data-mce-fragment=\"1\"\u003e QM\/TM1, QM\/TM2\u003c\/strong\u003e: attenuators for the modulation inputs QM\/TM1 and QM\/TM2 \u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-mce-fragment=\"1\"\u003e\u003cstrong data-mce-fragment=\"1\"\u003eSockets:\u003cbr data-mce-fragment=\"1\"\u003e \u003c\/strong\u003e\u003c\/p\u003e\n\u003cul data-mce-fragment=\"1\"\u003e\n\u003cli data-mce-fragment=\"1\"\u003e\n\u003cstrong data-mce-fragment=\"1\"\u003eIn1 \/ In2\u003c\/strong\u003e: audio inputs (In2 is normalled to In1)\u003c\/li\u003e\n\u003cli data-mce-fragment=\"1\"\u003e\n\u003cstrong data-mce-fragment=\"1\"\u003eOut1 \/ Out2\u003c\/strong\u003e: audio outputs\u003c\/li\u003e\n\u003cli data-mce-fragment=\"1\"\u003e\n\u003cstrong data-mce-fragment=\"1\"\u003eF\u003c\/strong\u003e: common frequency control input for both filters (~ 1V\/oct)\u003c\/li\u003e\n\u003cli data-mce-fragment=\"1\"\u003e\n\u003cstrong data-mce-fragment=\"1\"\u003e Delta FM\u003c\/strong\u003e: Control voltage for frequency spread, processed by the polarizer Delta FM\u003c\/li\u003e\n\u003cli data-mce-fragment=\"1\"\u003e\n\u003cstrong data-mce-fragment=\"1\"\u003eSFM1 \/ SFM2\u003c\/strong\u003e: single frequency modulation inputs, processed by the polarizers SFM1 and SFM2,  SFM1 is normalled to a fixed positive voltage, SFM2 is normalled to SFM1#\u003c\/li\u003e\n\u003cli data-mce-fragment=\"1\"\u003e\n\u003cstrong data-mce-fragment=\"1\"\u003eCFM1 \/ CFM2\u003c\/strong\u003e: common frequency modulation inputs, processed by the two voltage controlled polarizers controlled by CFM knob, CFM2 is normalled to CFM1\u003c\/li\u003e\n\u003cli data-mce-fragment=\"1\"\u003e\n\u003cstrong data-mce-fragment=\"1\"\u003e QM\/TM1, QM\/TM2\u003c\/strong\u003e: the addressing of these sockets\/attenuators is defined by internal jumpers. QM means Q modulation (i.e. resonance modulation), TM means filter type modulation (QM1 = resonance modulation filter 1, QM2 = resonance modulation filter 2, TM1 = filter type modulation filter 1, TM2 = filter type modulation filter 2), socket QM\/TM1 is normalled to a fixed positive voltage, QM\/TM2 is normalled to QM\/TM1\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-mce-fragment=\"1\"\u003eA 45 degrees triangle next to a socket means that the switching contact of the socket is normalled to a fixed positive voltage (SFM1, QM\/TM1).\u003cbr data-mce-fragment=\"1\"\u003e A vertical triangle indicates the normalling of two sockets (In1\u0026gt;In2, SFM1\u0026gt;SFM2, CFM1\u0026gt;CFM2, QM\/TM1\u0026gt;QM\/TM2).\u003c\/p\u003e\n\u003cp data-mce-fragment=\"1\"\u003eIf the filters do not behave as expected please pay attention to these peculiarities:\u003c\/p\u003e\n\u003cul data-mce-fragment=\"1\"\u003e\n\u003cli data-mce-fragment=\"1\"\u003eFor the controls \u003cstrong data-mce-fragment=\"1\"\u003eSFM1, SFM2, CFM, Delta F\u003c\/strong\u003e and\u003cstrong data-mce-fragment=\"1\"\u003e Delta FM\u003c\/strong\u003e the \u003cu data-mce-fragment=\"1\"\u003ecenter position is the neutral position\u003c\/u\u003e as these are polarizers. If the filter behaves unexpected these controls should be set to center positions for the time beeing. \u003c\/li\u003e\n\u003cli data-mce-fragment=\"1\"\u003eIn addition the sockets \u003cstrong data-mce-fragment=\"1\"\u003eSFM1 \u003c\/strong\u003e and\u003cstrong data-mce-fragment=\"1\"\u003e SFM2\u003c\/strong\u003e are normalled to fixed positive voltages provided that no patch cables are inserted into these sockets. In this case the controls \u003cstrong data-mce-fragment=\"1\"\u003eSFM1\u003c\/strong\u003e and \u003cstrong data-mce-fragment=\"1\"\u003eSFM2\u003c\/strong\u003e work as additional individual manual controls for the frequencies of filter 1 and 2 with center positions as neutral positions.\u003c\/li\u003e\n\u003cli data-mce-fragment=\"1\"\u003eFor the controls \u003cstrong data-mce-fragment=\"1\"\u003eF, Q, Level 1, Level 2, QM\/TM1\u003c\/strong\u003e und\u003cstrong data-mce-fragment=\"1\"\u003e QM\/TM2\u003c\/strong\u003e the \u003cu data-mce-fragment=\"1\"\u003e fully CCW position is the neutral position\u003c\/u\u003e as these are standard attenuators. If the filter behaves unexpected at least the controls \u003cstrong data-mce-fragment=\"1\"\u003eQM\/TM1\u003c\/strong\u003e and\u003cstrong data-mce-fragment=\"1\"\u003e QM\/TM2\u003c\/strong\u003e should be set to fully CCW. The reason is that via the normalling of the sockets \u003cstrong data-mce-fragment=\"1\"\u003eQM\/TM1\u003c\/strong\u003e and \u003cstrong data-mce-fragment=\"1\"\u003eQM\/TM2\u003c\/strong\u003e the associated controls generate control voltages which are added to the control voltages generated by the main contols (Type 1, Typ 2, Q). Which of these parameters are affected depends upon the settings of the internal jumpers. \u003cbr\u003e\n\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cp data-mce-fragment=\"1\"\u003eBy means of small circles at the bottom right side of the front panel the user can mark the function of the QM\/TM inputs. These assignments are possible:\u003c\/p\u003e\n\u003cul data-mce-fragment=\"1\"\u003e\n\u003cli data-mce-fragment=\"1\"\u003e\n\u003cstrong data-mce-fragment=\"1\"\u003eQM\/TM1\u003c\/strong\u003e controls QM1, \u003cstrong data-mce-fragment=\"1\"\u003eQM\/TM2\u003c\/strong\u003e controls QM2, the filter types are not controlled by external CVs\u003c\/li\u003e\n\u003cli data-mce-fragment=\"1\"\u003e\n\u003cstrong data-mce-fragment=\"1\"\u003eQM\/TM1\u003c\/strong\u003e controls TM1, \u003cstrong data-mce-fragment=\"1\"\u003eQM\/TM2\u003c\/strong\u003e controls TM2, the resonances are not controlled by external CVs\u003c\/li\u003e\n\u003cli data-mce-fragment=\"1\"\u003e\n\u003cstrong data-mce-fragment=\"1\"\u003eQM\/TM1\u003c\/strong\u003e controls QM1 and QM2 simultaneously, \u003cstrong data-mce-fragment=\"1\"\u003eQM\/TM2\u003c\/strong\u003e controls TM1 and TM2 simultaneously\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul data-mce-fragment=\"1\"\u003e\n\u003cli data-mce-fragment=\"1\"\u003e\u003cstrong data-mce-fragment=\"1\"\u003eApplications:\u003c\/strong\u003e\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul data-mce-fragment=\"1\"\u003e\n\u003cli data-mce-fragment=\"1\"\u003e\n\u003cstrong data-mce-fragment=\"1\"\u003eStereo filter\u003c\/strong\u003e: two different audio signals are connected to the audio inputs. At the outputs appear the filtered signals. The filterings depend upon the positions of the manual controls and the applied control voltages.\u003c\/li\u003e\n\u003cli data-mce-fragment=\"1\"\u003e\n\u003cstrong data-mce-fragment=\"1\"\u003eSerial mono filter:\u003c\/strong\u003e the mono signal is applied to audio input 1. Audio output 1 is connected to audio input 2. The filtered mono signal appears at audio output 2. One has to pay attention that the filter parameters are set in a way so that a signal will appear at the output. If for example a lowpass and a highpass are daisy chained the frequency of the lowpass has to be higher than the frequency of the highpass. Otherwise no signal will appear at the output.\u003c\/li\u003e\n\u003cli data-mce-fragment=\"1\"\u003e\n\u003cstrong data-mce-fragment=\"1\"\u003eParallel mono filter:\u003c\/strong\u003e the audio signal is fed to both audio inputs (e.g. via the normalled sockets In1\u0026gt;In2). By means of a mixer module the audio outputs 1 and 2 are mixed.\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Doepfer","offers":[{"title":"Default Title","offer_id":43496977498282,"sku":"","price":340.0,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0020\/5199\/7743\/products\/doepfer_a-121-sv_01.jpg?v=1663895788"},{"product_id":"doepfer-a-122-vcf","title":"[DISCONTINUED] Doepfer - A-122 VCF 3","description":"\u003cp\u003e\u003cstrong\u003eDoepfer A-122 VCF\u003c\/strong\u003e\u003c\/p\u003e\n\u003cp\u003e \u003c\/p\u003e\n\u003cp\u003e\u003cspan data-mce-fragment=\"1\"\u003emodule a-122 (vcf 3) is a voltage-controlled low-pass filter, which filters out the higher parts of the sound spectrum, and lets lower frequencies pass through.\u003c\/span\u003e\u003c\/p\u003e\n\u003cp\u003e\u003cspan data-mce-fragment=\"1\"\u003ethe cut-off frequency determines the point at which filtering takes effect. you can control this manually, or by voltage control (filter modulation, for instance by an lfo). two cv inputs are available.\u003c\/span\u003e\u003cbr data-mce-fragment=\"1\"\u003e\u003cbr data-mce-fragment=\"1\"\u003e\u003cspan data-mce-fragment=\"1\"\u003ethe cut-off slope is -24 db\/octave. the circuitry uses a curtis cem 3320 chip, and is very similar to the classic oberheim filter sound. because of its different circuitry and controls, the a-122 has a considerably different sound to the \u003c\/span\u003e\u003ca href=\"https:\/\/www.analoguehaven.com\/doepfer\/a120\" data-mce-fragment=\"1\"\u003ea-120\u003c\/a\u003e\u003cspan data-mce-fragment=\"1\"\u003e 'moog-like' filter, especially in the way the resonance behaves.\u003c\/span\u003e\u003cbr data-mce-fragment=\"1\"\u003e\u003cbr data-mce-fragment=\"1\"\u003e\u003cspan data-mce-fragment=\"1\"\u003evoltage controlled resonance: on the vcf 3, resonance can be controlled not just manually, but by voltages as well, right up to self-oscillation. in this case, the filter behaves like a sine wave oscillator.\u003c\/span\u003e\u003c\/p\u003e","brand":"Doepfer","offers":[{"title":"Default Title","offer_id":45078024683690,"sku":"","price":120.0,"currency_code":"USD","in_stock":false}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0020\/5199\/7743\/files\/a122.jpg?v=1694717821"},{"product_id":"doepfer-a-105-2","title":"Doepfer - A-105-2","description":"Module A-105-2 is a voltage controlled low pass filter with 24dB\/octave slope. It is the successor of the \u003ca href=\"https:\/\/doepfer.de\/a105.htm\"\u003eA-105\u003c\/a\u003e which had to be discontinued because the obsolete SSM2044 filter circuit. The A-105-2 is based on the SSI2144 which is in turn the successor circuit of the SSM2044. The features of both modules are nearly the same. The main difference is the clearly reduced front panel width of the A-105-2 (4HP instead of 8HP) and the associated changes of the controls and sockets positions. In addition the A-105-2 is equipped with 2 audio inputs.\n\u003cp\u003eThe module has these controls and in\/outputs available:\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eControl Frequ: manual frequency control\u003c\/li\u003e\n\u003cli\u003eControl FCV2: attenuator for the frequency control voltage applied to socket FCV2\u003c\/li\u003e\n\u003cli\u003eControl Q: manual resonance control\u003c\/li\u003e\n\u003cli\u003eControl QCV: attenuator for the resonance control voltage applied to socket QCV\u003c\/li\u003e\n\u003cli\u003eControl Input 1 Level: attenuator for the audio input signal applied to socket Input 1\u003c\/li\u003e\n\u003cli\u003eSocket Input 1: audio input 1 (with attenuator)\u003c\/li\u003e\n\u003cli\u003eSocket Input 2: audio input 2 (without attenuator)\u003c\/li\u003e\n\u003cli\u003eSocket FCV1: frequency control voltage 1 (without attenuator, about 1V\/oct scale)\u003c\/li\u003e\n\u003cli\u003eSocket FCV2: frequency control voltage 2 (with attenuator)\u003c\/li\u003e\n\u003cli\u003eSocket QCV: resonance control voltage (with attenuator)\u003c\/li\u003e\n\u003cli\u003eSocket Out: audio output\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul\u003e\n\u003cli\u003eTechnical notes:\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul\u003e\n\u003cli\u003eFrequency range: about 15Hz ... 15 kHz\u003c\/li\u003e\n\u003cli\u003eResonance up to self oscillation\u003c\/li\u003e\n\u003cli\u003eMax. input voltage at Input 2 without clipping\/distortion: about 15Vpp\u003c\/li\u003e\n\u003cli\u003eMax. output voltage without clipping\/distortion: about 15Vpp\u003c\/li\u003e\n\u003cli\u003eThe signals of both inputs are mixed before they are processed by the filter. This saves an external mixer for small setups.\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Doepfer","offers":[{"title":"Default Title","offer_id":45529756532906,"sku":"","price":138.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0020\/5199\/7743\/files\/A-105-2.jpg?v=1709157997"},{"product_id":"doepfer-a-105-2v","title":"Doepfer - A-105-2V","description":"Module A-105-2 is a voltage controlled low pass filter with 24dB\/octave slope. It is the successor of the \u003ca data-mce-fragment=\"1\" href=\"https:\/\/doepfer.de\/a105.htm\" data-mce-href=\"https:\/\/doepfer.de\/a105.htm\"\u003eA-105\u003c\/a\u003e which had to be discontinued because the obsolete SSM2044 filter circuit. The A-105-2 is based on the SSI2144 which is in turn the successor circuit of the SSM2044. The features of both modules are nearly the same. The main difference is the clearly reduced front panel width of the A-105-2 (4HP instead of 8HP) and the associated changes of the controls and sockets positions. In addition the A-105-2 is equipped with 2 audio inputs.\n\u003cp data-mce-fragment=\"1\"\u003eThe module has these controls and in\/outputs available:\u003c\/p\u003e\n\u003cul data-mce-fragment=\"1\"\u003e\n\u003cli data-mce-fragment=\"1\"\u003eControl Frequ: manual frequency control\u003c\/li\u003e\n\u003cli data-mce-fragment=\"1\"\u003eControl FCV2: attenuator for the frequency control voltage applied to socket FCV2\u003c\/li\u003e\n\u003cli data-mce-fragment=\"1\"\u003eControl Q: manual resonance control\u003c\/li\u003e\n\u003cli data-mce-fragment=\"1\"\u003eControl QCV: attenuator for the resonance control voltage applied to socket QCV\u003c\/li\u003e\n\u003cli data-mce-fragment=\"1\"\u003eControl Input 1 Level: attenuator for the audio input signal applied to socket Input 1\u003c\/li\u003e\n\u003cli data-mce-fragment=\"1\"\u003eSocket Input 1: audio input 1 (with attenuator)\u003c\/li\u003e\n\u003cli data-mce-fragment=\"1\"\u003eSocket Input 2: audio input 2 (without attenuator)\u003c\/li\u003e\n\u003cli data-mce-fragment=\"1\"\u003eSocket FCV1: frequency control voltage 1 (without attenuator, about 1V\/oct scale)\u003c\/li\u003e\n\u003cli data-mce-fragment=\"1\"\u003eSocket FCV2: frequency control voltage 2 (with attenuator)\u003c\/li\u003e\n\u003cli data-mce-fragment=\"1\"\u003eSocket QCV: resonance control voltage (with attenuator)\u003c\/li\u003e\n\u003cli data-mce-fragment=\"1\"\u003eSocket Out: audio output\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul data-mce-fragment=\"1\"\u003e\n\u003cli data-mce-fragment=\"1\"\u003eTechnical notes:\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003cul data-mce-fragment=\"1\"\u003e\n\u003cli data-mce-fragment=\"1\"\u003eFrequency range: about 15Hz ... 15 kHz\u003c\/li\u003e\n\u003cli data-mce-fragment=\"1\"\u003eResonance up to self oscillation\u003c\/li\u003e\n\u003cli data-mce-fragment=\"1\"\u003eMax. input voltage at Input 2 without clipping\/distortion: about 15Vpp\u003c\/li\u003e\n\u003cli data-mce-fragment=\"1\"\u003eMax. output voltage without clipping\/distortion: about 15Vpp\u003c\/li\u003e\n\u003cli data-mce-fragment=\"1\"\u003eThe signals of both inputs are mixed before they are processed by the filter. This saves an external mixer for small setups.\u003c\/li\u003e\n\u003c\/ul\u003e","brand":"Doepfer","offers":[{"title":"Default Title","offer_id":45783930175658,"sku":"","price":156.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0020\/5199\/7743\/files\/A-105-2V.jpg?v=1712959476"},{"product_id":"doepfer-a-121d","title":"Doepfer - A-121d Dual Multimode Filter","description":"\u003ch2 class=\"h2\"\u003eProduct Info\u003c\/h2\u003e\n\u003cp\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003cdiv class=\"entry\"\u003e\n\u003cp\u003eModule A-121d is a special dual multimode filter which can be used for parallel or serial organized dual mono filters. Even stereo applications are imaginable. The filter are based on two special circuits: one with highpass and bandpass outputs, the other with lowpass and bandpass outputs. It’s a new filter design that is not used so far in any other A-100 filter module.\u003c\/p\u003e\n\u003cp\u003eWe attached great importance to the usability of the manual controls and CV inputs for dual filter applications: for the filter frequencies of both filters a common control (Frequ.) and a difference control (Delta, filter spread) are available. For both parameters even CV inputs are available (FCV, DCV). The resonance (Q1, Q2), the sensitivity of the individual frequency control input (FCV1, FCV2) and the level of the audio input (In1, In2) are adjusted by means of the individual controls for each filter.\u003c\/p\u003e\n\u003cp\u003eThe module has a simple audio mixing unit available with the inputs Mx1 and Mx2, and the output MxO. Provided that the mixer inputs are open bandpass 1 and bandpass 2 are normalled to the sockets Mx1 and Mx2. All other filter types are realized by connecting the other filter outputs (H1 = highpass 1, L2 = lowpass 2) to the mixer inputs.\u003c\/p\u003e\n\u003cp\u003eTwo or more modules can be combined to realize e.g. four or more parallel wired bandpass filters.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eSpecifications\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eWidth: 8hp\u003c\/li\u003e\n\u003cli\u003eDepth: 45mm\u003c\/li\u003e\n\u003cli\u003ePower: +12V 30mA \/ -12V 30mA\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e","brand":"Doepfer","offers":[{"title":"Default Title","offer_id":46263785095338,"sku":"","price":159.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0020\/5199\/7743\/files\/A-121-2.jpg?v=1727389937"},{"product_id":"doepfer-a-121dv-dual-multimode-filter","title":"Doepfer - A-121dV Dual Multimode Filter","description":"\u003ch2 class=\"h2\"\u003eProduct Info\u003c\/h2\u003e\n\u003cp\u003e\u003cbr\u003e\u003c\/p\u003e\n\u003cdiv class=\"entry\"\u003e\n\u003cp\u003eModule A-121d is a special dual multimode filter which can be used for parallel or serial organized dual mono filters. Even stereo applications are imaginable. The filter are based on two special circuits: one with highpass and bandpass outputs, the other with lowpass and bandpass outputs. It’s a new filter design that is not used so far in any other A-100 filter module.\u003c\/p\u003e\n\u003cp\u003eWe attached great importance to the usability of the manual controls and CV inputs for dual filter applications: for the filter frequencies of both filters a common control (Frequ.) and a difference control (Delta, filter spread) are available. For both parameters even CV inputs are available (FCV, DCV). The resonance (Q1, Q2), the sensitivity of the individual frequency control input (FCV1, FCV2) and the level of the audio input (In1, In2) are adjusted by means of the individual controls for each filter.\u003c\/p\u003e\n\u003cp\u003eThe module has a simple audio mixing unit available with the inputs Mx1 and Mx2, and the output MxO. Provided that the mixer inputs are open bandpass 1 and bandpass 2 are normalled to the sockets Mx1 and Mx2. All other filter types are realized by connecting the other filter outputs (H1 = highpass 1, L2 = lowpass 2) to the mixer inputs.\u003c\/p\u003e\n\u003cp\u003eTwo or more modules can be combined to realize e.g. four or more parallel wired bandpass filters.\u003c\/p\u003e\n\u003cp\u003e\u003cstrong\u003eSpecifications\u003c\/strong\u003e\u003c\/p\u003e\n\u003cul\u003e\n\u003cli\u003eWidth: 8hp\u003c\/li\u003e\n\u003cli\u003eDepth: 45mm\u003c\/li\u003e\n\u003cli\u003ePower: +12V 30mA \/ -12V 30mA\u003c\/li\u003e\n\u003c\/ul\u003e\n\u003c\/div\u003e","brand":"Doepfer","offers":[{"title":"Default Title","offer_id":46263788142762,"sku":null,"price":213.0,"currency_code":"USD","in_stock":true}],"thumbnail_url":"\/\/cdn.shopify.com\/s\/files\/1\/0020\/5199\/7743\/files\/a-121dv.jpg?v=1727390113"}],"url":"https:\/\/www.noisebug.live\/collections\/doepfer-filters.oembed","provider":"Noisebug","version":"1.0","type":"link"}