Modular Analog Synthesis

There are several major manufacturers of synth modules, in both kit and pre-assembled forms. This web site is my little contribution to that world. My intent is not to be an exhaustive catalog of the history of analog synths, or a reviews and interviews site. This is a place to find information on currently available analog synthesizers and related tools and parts. Hope you like it... -Doug

DISCLAIMER: Inclusion here does not imply endorsement by me. I have personal experience with some, but NOT ALL of the companies and/or people mentioned here. Everybody has different needs and expectations. All links are included to help you do your own research and reach your own conclusions. If I have included erroneous information, please let me know and I will correct it as soon as I can.

NOTE March 2009 - I'm sorry, but I've been sick for a couple months and haven't updated anything. I'm also in the process of transferring all of my web pages to a new ISP. (I used to have everything at but I don't like Apple's new "".)

You can contact me at doug at analog notes dot com


Modular analog synthesizers are musical instruments that are typically made up of discreet analog electrical circuits. These circuits may be mounted on individual panels, or may be grouped together in various chassis configurations.

While some manufacturers produce modules in sizes that no others make, there are three physical and electrical formats that are used by more than one module manufacturer - "Euro-Rack", the format used by Analogue Systems, Analogue Solutions, Doepfer and Plan B (with minor differences), "Frac-Rack", the format pioneered by PAiA and used by Blacet, Wiard and others, and "MOTM", used by Synth Tech and many other makers. Euro-Rack and Frac-Rack formats use 3U (5.25") of vertical space. MOTM uses 5U (8.75") of vertical space. Typically, this means that the Euro- and Frac-Rack modules use smaller knobs and jacks, while the MOTM modules use larger ones.

In general, european modules use 12v power and modules from the United States use 15v. There are exceptions, as well as some newer modules that use 5v power.

One of the biggest decisions you can make is whether to purchase full kits, parts, or pre-built modules. The main analog module kit supplier is Blacet, with a couple available from PAiA. Various parts are available from CGS (Ken Stone), Music From Outer Space, Oakley and others. Most other manufacturers sell complete modules. NOTE: Sadly, as of December 2006, Synthesis Technology will no longer provide full kits, although boards and panels should be made available in February 2007.

Other Information Sources

Email lists - There are several email lists where you can discuss analog synthesis.

Forums - There are a few forums with topics related to analog synthesis.

Other Sites - Articles and individual web sites.

There are several good books out there on the subject of analog synthesis. Check out Analog Days by Frank Trocco, Vintage Synthesizers by Mark Vail and Electronic Music Pioneers by Ben Kettlewell for overviews of the subject.

For technical information and articles about building analog synthesis circuits, check out these authors:


There are several stores out there selling analog synthsizers. Here are a few of them:



Tutorials and patches


There are several ways to control your analog synth. Analog modules typically use a voltage ("control voltage" or "CV") to change parameters (pitch, filter sweep, etc). Keyboards, sequencers and other controllers are available that can send cv signals directly, or you can use a MIDI to CV converter with a MIDI keyboard, sequencer or controller.


Sequencers are devices that output sequences of information that can be used to play notes or control other aspects of a performance. While there are both hardware and software sequencers, for the moment I am limiting this section to hardware only. Well...ok, except for one: Numerology ;-)

More info

Sequencer makers

MIDI-CV Converters

If you use a MIDI controller with your modular synth, you'll need some way of converting the MIDI information to the control voltages needed to communicate with your analog modules.


If you are using control voltages to set parameters on your analog synth, you may want some way of setting, or "tuning" your voltages so that your sounds are in tune with other instruments. You can use a voltmeter to set your control voltages or use a tuner to check the frequencies output from your VCO, but another way is to put a quantizer in your CV path. (NOTE: If you are using a MIDI-CV converter, it should quantize for you. Some MIDI-CV converters, such as the MOTM-650, have programmable tunings.)


Analog Metropolis

The Emulator Archive is now selling circuit boards for analog synthesizer modules, most using SSM or CEM chips.

Analogue Solutions

Analogue Solutions modules fit in the "Euro-rack" case. They require plus or minus 12v and plus 5v power.

Analogue Systems

Analogue Systems modules fit in a "Euro-rack" case. They require plus or minus 12v and plus 5v power. (Doepfer power connectors are built into the Analogue Systems case.)

Anywhere Instruments

This German company makes the Semtex XL ("Felix") which is cloned from the Oberheim SEM.


Gene Stopp's ASM-1 project was a DIY (Do It Yourself) project. There is a follow up project, called, amazingly enough, ASM-2.


Joint venture with Serge Tcherepnin, Ken Stone and Seth Nemec. Serge designs them, Ken makes the boards and Seth assembles them. (Nope, these modules don't actually use banana jacks...)

Blacet Research

Blacet modules are based on the "Frac-rack" system. They are 5.25" tall. They require plus or minus 15v power and are calibrated 1v/octave. Connections are made with 1/8" mini-jacks. See Synth Panels below if you want to use a Blacet module with an MOTM front panel.

Bride Chamber

Scott Deyo provides various parts and assembled modules.


Beautiful, but expensive!

Cat Girl Synth

See Ken Stone.

Club Of The Knobs

Club of the Knobs ("COTK") is in Portugal.

CMS - Cirocco Modular Systems

Phil Cirocco builds modules and systems and repairs ARP, Moog and EMS products.


This German company makes various module kits.


This Swedish company makes the S1 MK2 patchable synth and many Eurorack-style modules.


Many custom modules in Modcan and other styles. Now famous for the $995.00 Zeroscillator. Analogue Haven has some Cyndustries modules in stock - there seems to be a fairly long queue if you order directly from Cynthia.


Doepfer is the largest distributer of analog modules. I've heard that everything is designed in Germany and manufactured in China, resulting in very low prices. Doepfer modules fit in the Euro-rack case and require plus or minus 12v and plus 5v power.

Elby Designs

Laurie Biddulph provides a variety of boards and parts for ASM-2, AVRSYN, Pixie, Hobbit and more.

EFM - Electronics For Music

Tom Gamble runs this site and provides boards for the Wildcat, Tomcat and BassAce. NOTE: Apparently this will be the last run of BassAce boards - when this batch is gone, that's the end...

EMS - Electronic Music Studios

Creators of the Synthi A

Encore Electronics

Expressionist eight channel MIDI-CV converter and other MIDI controllers and retrofits, MOTM style Universal Event Generator and Frequency Shifter.


Paul Perry in Melbourne, Australia builds several pedals and a MIDI to CV converter. Pedals include the Resonator MS-20 filter, the Funk-A-Duck Envelope controlled filter, the Blue Ringer ring modulator and the Spacebeam Theremin, which seems to be similar to a Roland D-Beam.


Jered Flickinger and his father started Future Retro in 1996. Future Retro makes the Evolution monosynth and the Mobius sequencer.

Ken Stone (CGS)

Ken supplies many circuit boards for his own projects as well as for other designers.


Euro-rack size modules. Home of the Dalek and Vulcan modulators.


Ken MacBeth builds the M5 patchable synthesizer.

Magic Smoke Electronics

Tim Parkhurst and John Mahoney put together Magic Smoke Electronics, which is the sole source for Thomas Henry's designs and publications.

Mattson Mini Modular

George Mattson builds the Phoenix Series of micro modules.


Tube-based modules


Modules in Frac-rack sizes with Blacet-style power connectors.

Midwest Analog

Thomas Henry closed up shop in 2005, but authorized Magic Smoke to carry on.


Modcan A modules are 9" tall and 2.25" or 4.5" wide and use banana plugs. Modcan B modules use MOTM format.


What can I say? It was Dr. Bob. Great stuff here...


See Synthesis Technology

Music From Outer Space

Ray Wilson runs this Do It Yourself site


Tony Allgood designs analog modules as well as other projects like the TM3030 and TB-3031 TB-303 clones and the Filtrex filter bank. Oakley modules conform to the MOTM standard. Tony Allgood decided to close the shop in 2005, but there was enough demand that PC Boards are becoming available again. Tony seems to be working on another TB-303 clone too.


PAiA modules are based on the "Frac-rack" system. In fact, they invented it! Kits only. A really fun PAiA project is the FatMan, a monosynth that can be rack mounted or build in a table top cabinet. There are LOTS of modifications that can be done to the FatMan - it may be the most modified DIY synth in the world... And if you're in the market for a theremin, check out the PAiA Theremax kit.

Papareil Synth Labs

Plan B

Peter Grenader designs, builds and fixes electronics, including custom modules and various versions of the Milton sequencer. NOTE: DO NOT use Peter's buzzclick-music email address - it has been over run with SPAM. Use peter at ear dash group dot net instead.

Milton is a CV sequencer. No MIDI here! The standard design supplies four banks of 16 steps each and in theory, it can be expanded to 12 or more banks!


Schippmann is located in Berlin, Germany and makes the "ebbe und flut."


Modules, a whole panel at a time...

Studio Electronics

Studio Electronics is located in El Segundo, CA, USA and makes effects pedals and full width rack mount analog synths.

Spectral Audio

Spectral Audio is located in Switzerland. They make the Neptune II analog synth and the Cyclus 3 MIDI Analog Sequencer.

Synthesis Technology

Paul Schreiber is the creator of Synth Tech, home of the "MOTM" (rhymes with "modem") system. MOTM modules are made with the highest quality parts and designs. MOTM modules are based on the "U" rack size system. (1U = 1.75") They are 5U (8.75") tall and 1U (1.75") or 2U (3.5") wide. They require plus or minus 15v power and are calibrated at 1v/octave. Connections are made with 1/4" jacks. As of 2006, Synthesis Technology is shipping modules in FracRack format, available at Analogue Haven. NOTE: As of December 2006, Synthesis Technology is no longer supplying module kits.

Roger Arrick makes a variety of modules that are popularly called "dotcom". Roger provides very cost-effective modules with vintage style designs. Dotcom modules use 1/4" jacks and big knobs. Check out his web site - there is a LOT of great info there. One tantalizing thing is the Entry System Purchase Plan.

Synth Modules

Home of the PSIM-1. Brice Hornback started building his own modular and then created the PSIM-1, the "Programmable Synthesizer Inteface Module", which is a Frac-rack format module that can be programmed to output a variety of control voltages. NOTE: Brice is WAY behind in deliveries (as of October 2006, I believe it's been two years and five months), but he assures us that all ordered modules will be delivered. Brice recently posted that there are only something like 9 out of 56 left to be shipped. In the meantime, a group of developers has gotten together and created a Yahoo group called ComputerVoltageSources.

Synth Panels

I run a small business making panels and selling cables and other parts. I purchased all of the silkscreens for the original "Stooge Panels" that Larry Hendry and Dave Bradley used to make, plus I have added many new designs.


This Swiss company produces the "Small Monster" series including the Microcon monophonic synth, the Effexon analog processor and the Cyclodon 16 step sequencer, and the "Professional" series of analog modules.


Scott Juskiw has designed Blacet and MOTM add-ons (see Blacet and Synthesis Technology sections here) as well as several modules of his own, including the Neural Agonizer spring reverb and the Veeblefetzer signal level meter. Recently Scott developed a new multi-purpose board called the MUUB. As of December 2006, Scott tells me that he is thinking about resurrecting the TLN-854 Sword of Kahless next year! If you're interested in one, let him know.


This German company makes several synthesizers and modules.


Grant Richter builds the Wiard series of modules. His older, discontinued, 300 Series is highly collectible. Current 1200 Series modules are built by Grant himself. They are based on the "Frac-rack" system, require plus or minus 15v power and are calibrated 1v/octave. Connections are 1/8" mini-jacks. Currently available modules include a joystick, the Joystick Axis Generator, Noise Ring, and the Borg and Boogie Filters.

303 Corner

OK, I wasn't originally going to go down this path ;-) but I have an Oakley 3031 and a couple of x0xb0x kits on the bench. And so it begins...

Custom 303 Cases

Devil Fish

Robin Whittle in Melbourne, Australia applies lots of modifications to the TB-303.


This German company makes the "Bassline" and the very limited edition "Bombass".


Tony Allgood designed these 303 clones.

SE BassLine

Ripe101 has but a x0xb0x into a custom case.


x0xb0x is a TB-303 clone in kit form. It used to be available in kit form, but due to parts shortages, Ladyada is not longer selling full kits. Circuit boards and panels are still available, and parts lists and sources are available on the LadyAda forums.


WOW! This mod is amazing! Brian has been working on this for 15 months now. He has added many features to the x0xb0x. NOTE: As of July 2008, Brian has started shipping the x0xi0 back panel expansion and overdrive/distortion kit!

808 Corner

Wikipedia TR-808 page

MB808 - a TR-808 clone with a Midibox sequencer.

909 Corner

Wikipedia TR-909 page

Colin Fraser

Introspectiv - Trevor Page designed a clone of the TR-909, called the 9090. Circuit baords are still available!


Do It Yourself

There are several things you'll need to put together your own analog synth modules. First, you should have a well-lit work area. For tools, you'll need a soldering iron, screwdrivers and nutdrivers. If you buy kits from Blacet, PAiA or Synth Tech, that may be all you need. If you run into assembly or part troubles, you'll need diagnostic tools such as a Digital Multi Meter (DMM) or an Oscilloscope. It may also be nice to have a small parts vise as a "third hand" along with a large magnifying glass.

Helpful sites

Electronics Parts sources

UK US Prototyping Boards Patch Panels Soldering Matched Transistor Array ICs OTA info

Panels, screws, cabinets, etc

Circuit design


Low to medium price

Full fledged

Circuit modeling

Oscilloscopes, meters, etc

Buying new test gear can be quite expensive. Many of the national level laboratories regularly purchase new gear and auction off the old gear and there are several resellers who buy batches of that gear, clean it all up, test everything and then sell it individually. I have had very good luck dealing with John Bau of Precision Audio Services. Click here for John's current list of gear for sale.

Other Projects

And for some other DIY projects, check out:

Digital Projects