modular systems » Eurorack modules » sound processors » filters & resonators

Vactrol-based multimode filter based on a schematic by Nyle Steiner. Separate inputs for lowpass, bandpass and highpass.

Vactrol based combination of resonant 12dB lowpass filter and/or VCA. Inspired by the Buchla 292.

Reproduction of the legendary british diode lowpass filter. Resonance is possible up to self-oscillation but the behavior changes with the cutoff-frequency.

18dB low pass filter based on a modified Moog cascade. Resonance goes up to self-oscillation. The module sounds similar to the TB-303.

Another filter that uses the circuitry of a classic. This time it´s the Oberheim SEM (Synthesizer Expander Module), that was used in the Four-Voice and Eight-Voice for instance. The filter has a saturated fat sound and especially in lowpass mode it growls in the bass range, very mighty and powerful. The very sensitive audio input allows distortion of the audio signal which forms the sound even more.

A-106-6 works with the Oberheim Xpander's filter topology and features it's sixteen filter types, arranged in two banks. Each filter tyes are available simultaneously at individual outputs. Besides the usual filter types with different slopes you'll also find combinations of differenty filter types and all-pass filters as well.

The module contains 26 very different filter types which can be combined each after the other. You can morph or switch between those filter chains manually, with contol voltage or with a clock signal. 15 filter types are known from the Oberheim Matrix 12 and there additional 21 new filter types.

The A-108 is a classic Moog lowpass filter with up to 48dB slope and a very soft and round sound. There are four lowpass outputs for 6, 12, 24, 48dB and also a banpass output.

The A-120 features the classic Moog low pass filter built around a transistor cascade It has a slope of 24dB per octaveand three three modulation inputs for controlling the cutoff frequency. Self-oscillation of the resonance is possible only above ca. 300Hz.

24dB low pass filter based on a Curtis filter circuit which is known from many polyphonic 1980s synthesizers. It features voltage control of cutoff frequency and resonance; self-oscillation is possible, too.

A multimode filter is based on a very special filter circuit used in the EPD Wasp, an English synthesizer of the late 1970ies. The sound is full of character, dirty, with an unstable resonance and a trend to distort. Who is in search of a very aggressive, sick filter definitely should take the A-124 into consideration.

Three parallel, voltage controlled, resonant bandpass filters (each switchable to lowpass per jumper), each with an own LFO or CV input with attenuator. Separate outputs for each filter and a mixed output. Very well suitable for living filtering or as a formant filter with modulation (unlike A-104).

Fixed filterbank with a low pass, thirteen bandpass filters and one high pass. Each filter has a level control which even enables you to mute the specifical band.

This low pass filter is a very good -24dB/octave Moog filter, based on the classic Moog cascade with selected, low-noise transistors.

Being the successor of the RS-100, the new "S" version features several improvements regarding stability, tracking, distortion behavoiur and also the frequency range.

The RS-110 is a resonant analog multimode filter with excellent sound, resonance and four simultaneously available filter types. An insert function in the feedback loop allows you to insert other audio processors.
Thanks to a new dual-bus concept, this circuit is fully compatible to Doepfer’s Eurorack standard.

Filterbank module with eight fixed filter frequencies, each one octave apart. It is the successor of the RS-210 which was based on a rare 70ies filter bank from EMS. The newer version has different frequencies for a wider frequency range and the filter have a higher slope.

The RS360 Vocal / Phase Filter contains three voltage controlled resonant multimode filters that are summed at the outputs. The low pass and high pass filters with a slope of -24db/octave whilst the band pass and notch filters work with -12dB slope. The module is suited for creating vocal-like sounds and formants.

Genuine EMS Synthi filter. This legendary filter can be switched between pre 1974 and post 1974 filter type and response. For the first time response can be voltage controlled which was designed on the circuit board but not available on the matrix. This module is made under license from EMS.
Thanks to a new dual-bus concept, this circuit is fully compatible to Doepfer’s Eurorack standard.

The DMF-2 module consists of two identical filters with two modes: lowpass and a quasi-bandpass which are available simultaneously at separate outputs. Each filter works selectively with different filter slopes and allows overdriven sound by saturation. By lots of in- and output combinations the module can be used as two independent filters or as a parallel dual filter.

We currently do not accept pre-orders for Cwejman products. If you are interested in this module, please use the availability notification. The number of Cwejman circuits is limited. Therefore, we recommend you to order online IMMEDIATELY when a module becomes available. Enquiries via e-mail or telephone are usually not fast enough. (More detailed information can be found on the product page.)

The module Cwejman MMF-2 is a stereo multimode filter. It can be used as a true stereo filter or like two independent filters. Besides the cwejman´esque clean sound the filter has a switchable saturation stage allowing you for creating distorted wild sounds. Lots of filter types, voltage controlled parameters and also the dry/wet parameter make this filter a complex tool for sound processing.

We currently do not accept pre-orders for Cwejman products. If you are interested in this module, please use the availability notification. The number of Cwejman circuits is limited. Therefore, we recommend you to order online IMMEDIATELY when a module becomes available. Enquiries via e-mail or telephone are usually not fast enough. (More detailed information can be found on the product page.)

The Cwejman MMF-6 is a flexible multi-mode filter with six simultaneously available filter types at individual outputs. Besides the clear sound known from Cwejman the module also has "saturated" outputs for a nice nasty sound. Way cool!

We currently do not accept pre-orders for Cwejman products. If you are interested in this module, please use the availability notification. The number of Cwejman circuits is limited. Therefore, we recommend you to order online IMMEDIATELY when a module becomes available. Enquiries via e-mail or telephone are usually not fast enough. (More detailed information can be found on the product page.)

The RES-4 is a voltage controllable quad resonance filter. It bases upon Cwejman´s VC-EQ module but features explicitely greater parameter ranges and thus it is possible to create somewhat extreme sounds. An awesome module.

We currently do not accept pre-orders for Cwejman products. If you are interested in this module, please use the availability notification. The number of Cwejman circuits is limited. Therefore, we recommend you to order online IMMEDIATELY when a module becomes available. Enquiries via e-mail or telephone are usually not fast enough. (More detailed information can be found on the product page.)

The first widely available modular release of the Polivoks filter circuit is an officially clone built on the basis of original russian spare parts.The -12dB filter has parrallel lowpass and bandpass outputs sounding somewhat nasty. Unlike the original here you have CV inputs which will ad to the filter's possibilities.

Doctor Octature can be used in two different ways. On the one hand it is a octature-LFO which means it´s a sinewave LFO with eight outputs, shifted 45° in phase to each other. On the other hand it is a lowpass filter with eight outputs. It´s design is similar to the analog filters from Roland.

State-variable multimoder filter that is very suitable for small portable systems because of it´s small width of 6HP only. The filter tracks well more than four octaves and generates a clean sine wave at self oscillation so you can use the module quite well as a sinewave oscillator.

The MA35 module is a combination of an analog VCF and a VCA. The filter section is based on the Korg35 filter as used in the legendary Ms-10 synthesizer. It is switchable between lowpass and highpass, has two audio inputs and creates the classic Korg sound i.e. it can sound from smooth to nasty. The VCA is a Korg circuit as well and is built with period (not original, hard-to-find) transistors and op-amps to keep the character as authentic as possible. This vintage-isation makes the module a little raw and noisy but in a very charming way.

The Optomix is a direct coupled, two channel low pass gate utilizing 4 vactrols to provide simultaneous voltage control over amplitude and frequency content of a signal. It is in essence, a VCFA.

Additionally Optomix offers a summing stage complete with an AUXiliary IN allowing for the chaining of multiple units to create larger mixes.

The Toppobrillo Multi Filter is a new/ traditional state-variable design based on a great modern quad VCA chip, the SSM2164. This, in part, helps make the Multifilter what it is, a clean, quiet, stable and very controllable filter at it´s core, without limiting its palette, well suited for processing anything you can run through it. Much attention was paid to the range and feel of controls, inputs and overall usability, including all options standard and more; a very versatile processing tool with amazing sound in a small package,

The Z2040 is a discrete clone of the Prophet 5`s low pass filter with come additonal features like voltage controlled gain and resonance. The gain parameter allows for overdriving the filter.

This expansion module for the WMD Phase Displacment Oscillator consists of four individual -24dB low pass filters that provide for an anti-aliased output.

The Micro Hadron Collider or uHC, is  dual State-Variable multimode filter. You can use it in series or in parallel configurations or as two separate 12dB filters, as one 24dB filter or as a combination of both eg. dual bandpass.

The E440 is an analog discrete low pass filter with three simultaneous filter types (-12dB, -18dB & -24dB). It also offers overdrive and voltage controlled resonance.

The Eurorack module Richter Dual Borg by Malekko combines both vactrol based (meanwhile discountinued) Borg filter modules together with their different characteristics and timbres. Left hand is the slower but mellow sounding Borg 1, to the right the faster and aggressive Borg 2. Both can be used simultaneously, in series and parallel.

Based on the formant filter form the Trautonium the A-104 offers four resonant filter, switchable between low pass and band pass. Especially in band pass mode is good for creating static resonances, formats and vocal sounds.

More than a MS-20 filter clone! X-tremly flexible 12dB lowpass and 6dB highpass with separate ins for the filters and endless combinations of how to mix the filters and their polarities. An extreme, exceptional and experimental module with very strange behavior!

The A-105 is a 24dB low pass filter that bases on the SSM 2044 chip that was used amongst others in following units: Korg Polysix, Korg Mono/Poly, Fairlight II, PPG Wave 2.2 und 2.3, Emu SP-1200, Siel DK600, Siel Opera 6. The first Prophets used the SSM2040 - the precedessor of the 2044 - that generates a very similar sound. The filter convinces with a very powerful sound. The resonance starts quite early to color the signal and makes a big range of sounds possible up to self-oscillation. The latter provides a very clean sine wave - no wonder, because the SEM2044 chip wasn´t designed only as a filter core but also as a sine wave oscillator.

Analog, resonant and voltage controllable multi mode filter with four outputs, one of them with an integrated VCA. Mutable Instruments call the filter as "liquid filter" and that describes the sound pretty well.

Entirely dicrete VCA combined with a vactrol controlled low pass filter. The sound is gorgeous somewhere between wood and acid and the input stage can distort really well when desired. Did we already mention the lack or any ICs in the signal path? In best old school fashion this thing is built only with transistors what definitely affects the sound.

These old school 24dB filters take you on a time travel into the 60ies, directly into the tape music studios!
Left-hand a high pass, right-hand a low pass; they can't oscillate but growl and screech a lot. This dual filter is discrete, without opamp ICs and is based on the core of an old 100-series Buchla design

The big, sorry HUGE brother of the great RES-4 even outperforms it's concept by far. This module are four ultra stable multimode filters / resonators with three different resonance modes, three switchable filter types (plus a fixed notch), individual in- and outputs per filter and the Master section known from the RES-4 plus dry/wet controls.
What a monster module for filter and resonator use, generating drum sounds, equalizing etc.

We currently do not accept pre-orders for Cwejman products. If you are interested in this module, please use the availability notification. The number of Cwejman circuits is limited. Therefore, we recommend you to order online IMMEDIATELY when a module becomes available. Enquiries via e-mail or telephone are usually not fast enough. (More detailed information can be found on the product page.)

Touell Skouarn's idea of a fiter is, as expected, pretty weird as it is based on an inductor. According to this unique design the sound is extraordinary and somewhere in between a phaser-ish band pass, distortion and a gnarly wahwah with a vintage character.

Unbelievably lovely sounding clone of the lowpass filter from the Roland 100m with additional phase-invertted 12dB output. Prominent leads, abrasive basslines and killer acid chirps are easy to achieve with this filter. We are amazed!

Faithful clone of the quirky low pass filter from the Moog Rouge. After the VCF the module has a VCA which you may use but don't have to.

Four analog bandpass filters in parallel which stamp a strongle vocal character to your audio. The filters can't be controlled individually, in fact a special CV processor is used to determine first the size of the "mouth" and second to select the vocals.
A very stunning module with a special character and an awesome, liquid, organic sound.

Long-awaited and stunnigly beautiful State Variable Multimode filter built around transistors, combining the likewisely transistor-based mixer of Moog's CP3.
Soundwise somewhere in between the creaminess and wetness of a FrequenSteiner and the pleasant sound of transistors and for that reason one of THE filter modules of 2014!

Faithful clone of the early Minimoog lowpass filter with all transistor pairs selected and matched by hand what was nt the case with the later Minis. The circuitry runs internally with exactly the same operational voltages and the transistors have the same specifications as 45 years ago. AJH Synth added voltage control of reconance and selectable overdrive.

FXDf stands for Fixed Filter and that's exactly what this module is about. It features individual inputs for different filter slopes and six outputs with fixed frequency bands.

Totally unique is the RxMx (pronounced RixMix) because it combines the organic behaviour of lopass gates with the characteristics of a six-channel mixer and these of a crossfader. The mixer is more a scanner with voltage control addressed selection and modulation of a lopass-gate-channel and/or the number of neighbor channels. "Pinging" creates the simulation of a reverb because of the inert Vactrols' slow decay.