I've always been interested in electronics and music.  I played in a band in the '60's with a Farfisa organ and a Vox Essex Bass amp (I still have both).  My introduction to electronic synthesizers was an ARP 2600 at Evergreen State College and later on an ARP Odyssey.  My first synthesizer was an Ensoniq EPS-16+ but I longed for analog.  I starting with a PAiA Fatman and then progressed to a Matrix-1000, Sequential Circuits Six-Trak, Arp Odyssey, Arp Avatar / Sequencer, and finally began to build my modular in 2001.  My electronics experience started in middle school and by high school I had a part time repair business which helped fund my electronics college education.  Here is a photo of my high school repair bench.

The Synth

This synthesizer has now grown to over 100 modules and I never imagined it would have gotten this large.  Originally I wanted to keep my synthesizer all analog but a small portion of my modules are now digital.  I have a few out-board digital effects units but I still prefer my reel-reel tape for echoes and delays.  Hopefully you'll find some useful information here. I've documented my modular designs, many of my module modifications, and my synthesizer projects with reference information and photos.

This Site

I make nearly everything I do public domain.  I've learned from others and this site is help others learn from what I have done.  I'm delighted by the number of emails and feedback I receive from people using this site and the number of hits which is ranked by Xmarks and Top20Sites.  Send me an email if you have a question.


My Help

I've done electronics repair and restoration for decades.  I used to operate my own electronics repair business and I restore vintage radios as a hobby.  I repair a lot of tube radio, audio, and music equipment and I've done microprocessor and digital system design for Tektronix so I enjoy working on vintage synthesizer restoration.  Most of my synthesizer, organ, and amplifier collection were purchased broken for parts but I usually then end up restoring them - I just hate to part out vintage equipment.  I have the time and interest to be able to help and assist fellow Synth-DIY'ers with their projects and formed Modular Synthesis, LLC to help. I've even helped successfully diagnose and repair modules by email.  Contact me if I can be of help or assistance with your project, design, repair, or restoration.


Contact me if I can be of help or assistance with your project, repair, design, or restoration.

Repairs, custom projects and customer testimonials

Items that I have currently for sale

I spent 34 years at Tektronix working with some of the best people in all parts of the company: Computer Graphics, Video & Networking, and Test & Measurement.  I've since retired to enjoy my hobbies and now have time to devote to my music and electronic projects as well as volunteer at the vintageTEK museum.

My professional information on LinkedIn

My Tektronix memorabilia

My designs are indicated with a superscript¹

Modifications of existing designs are indicated with a superscript²

Quick Links

Latest Projects

ComputerVoltageSource Module
Ian Fritz DoubleDeka VCO²  New CVS eight channel module¹
5U E950 Circuit Bent VCO  New CVS 2x16 LCD display¹
CGS-35 Steiner VCF²  New CVS four channel module (PSIM software compatible)¹
Moon Modular M569 companion CVS Kurzweil ribbon controller¹
Thomas Henry mega percussive synthesizer Synthmodules.com PSIM and SpeakJet²
5U E560 deflector shield CVS and PSIM I/O expansion module¹
Barton dual quantizer² CVS and PSIM Programs¹
OMS-820 lag companion Arduino-based ComputerVoltageSource¹
DJB-021 pan-crossfade²
5U Buchla 266 source of uncertainty² Synthesizer Restoration and Builds
Flight Of Harmony plague bearer Aries modules
Polivoks VCF² Buchla modules  Updated
5U E580 sampling mini-delay Fonitronik mh21 Triple Resonator  New
Ian Fritz 'threeler' 3rd order VCF² Loft 450 Delay Line/Flanger
DJB-020 tap tempo LFO¹ Milton Sequencer
Synthesizer XY laser² Moog modules  Photos  Updated
Buchla pulser-crossfader-timbre generator² Moog Sonic Six synthesizer
5U E340 cloud generator² PAiA 2720 Synthesizer
5U E350 morphing terrarium² Papareil Labs Quantix-8²
Magic Smoke TH-301 VC-LFO² Roland System 100 - 140 module
Bridechamber wogglebug² SCI Model 700 Programmer
LCD oscilloscope module² SCI Model 800 Sequencers
Jürgen Haible polymoog® resonator²
Jürgen Haible living VCO² Related Musical Projects
   Circle machine sequencer¹
Modular Synthesizer Information MIDI 88 note keyboard²
Module listing by cabinet MIDI bass pedals¹
Custom modules design files and photos¹ MIDI processor¹
Purchased modules and modifications² SpeakJet  speech synthesizer²
Dotcom modules Yamaha Tenori-On
Main cabinets & power distribution¹
Side cabinets & power distribution¹ Organs and more
Hammond B-3 and Leslie 142
Reference Information Hammond M-3 tonewheel generator  Photos
Modular synth tips Hammond vibrato scanner module²
Parts and DIY information Hammond zinc whiskers Photos
Making PCB brackets Organs, keyboards and amplifiers
440 Hz sine wave reference oscillator¹  Part for sale   
Power supply sequencing¹ Electronics Projects and Repairs
PT2395 delay module² Electronic project information
Electronic repairs and tips information
Photos, Videos, and Sound Samples Fender Tremolux Restoration
Photo album Sony TA-E88 Restoration
Video and Sound samples
Hammond M-3 tonewheel generator
Hammond zinc whiskers

Synthesizer Projects

Modular Synthesizer

My modular synthesizer now consists of 115 modules including Analog Metropolis, Blacet, Bridechamber, Catgirl Synth, Encore, Roman Fillipov, Flight Of Harmony, Ian Fritz, Jürgen Haible, Larry Hendry, Magic Smoke Electronics, Moon Modular, MOTM, Natural Rhythm Music, Neil Johnson, Oakley Sound Systems, Synthcube, Synthesizers.comSynthmodules.com, and about two dozen of my own designs.


Synthesizer modules and external equipment index

Design files and photos for my custom modules¹

Information, mods, and photos for purchased modules²

Parts and construction information

MP3 samples of some of my favorite patches



Modular CV Keyboard

I rebuilt an ARP-3604 keyboard with a wood cabinet and updated electronics.

Information & photos for my ARP CV keyboard²



Modular Cabinets and Power Distribution

I built a 19" rack cabinet (30 modules and 2U standard rack) and a four stack of wood cabinet (96U).  I later replaced the 19" rack cabinet with a four stack wood side cabinet (36U+10MU).

Info & photos of my initial 19 inch rack cabinet¹


Info & photos for my wood cabinets & power distribution¹


Info & photos for my side cabinets & power distribution¹


Info & photos for my power-on delay¹

Info & photos for my rear AC mains module¹



ComputerVoltageSource Module


I designed the ComputerVoltageSource module using an AtomPro28.  Features include:
     8 analog inputs (0 to 10 volt with 0 to -5 volt offset at 10 bit resolution)
     8 analog outputs (0 to 10 volt at 12 bit resolution)
     3 digital inputs
     MIDI in / out
     I2C expansion (for additional inputs and outputs)
     2x16 LCD display.

Info and photos for the ComputerVoltageSource module¹


Info and photos for the ComputerVoltageSource display¹

Information and photos for a four channel version¹

Information and photos for a dedicated ribbon controller¹

Arduino-based ComputerVoltageSource¹  New



Synth Display Modules

I built an external display using a 2x20 LCD module with MIDI or serial input and three display modes.

Information and photos for my external display module¹


I built two dedicated displays for my programmable PSIM (2x8 LCD) and ComputerVoltageSource (2x16 LCD) modules.

Information and photos for my PSIM 2x8 display¹


Info and photos for the ComputerVoltageSource display¹



MIDI Bass Pedals

I built a set of MIDI bass pedals using Hammond organ pedals and an AtomPro24 controller.  Features include:
       Normal, Mono, and 'Sticky" modes (sticky=note held until next note played)
       Normal, One-Shot, and 'Sticky" arpeggiator modes
       5 built-in arpeggiator sequences and a user-recordable 100 note sequence
       Normal, -1 and +1 octave select
       MIDI in merge
       Internal or MIDI clock
       External LCD note display

Information and photos for my MIDI bass pedals¹



88 Key MIDI Keyboard

I built an 88 key MIDI keyboard from a salvaged Kurzweil Ensemble Grand Mark III digital piano.  I used the original keyboard controller and built a custom wood cabinet.

Information and photos for my 88 note keyboard²



MIDI Processor

I built a MIDI processor which is self-powered and provides multiple transformations.  Features include:
     Key transpose
     Channel transpose
     Keyboard split
     Keyboard reverse
     Specific continuous controller transforms

Information and photos for my MIDI processor¹



A440 Reference Oscillator

I designed a 440 Hz sine wave reference oscillator using only two 8 pin DIP components.

Information and photos for my A440 oscillator¹



Hammond Vibrato Scanner Module

I built an external electro-mechanical vibrato and chorus using a Hammond Organ scanner and delay line.  A small DC motor and speed controller varies the vibrato frequency.

Information and photos for my Hammond vibrato scanner



AVR Synth

I built the AVR Synth PCB to have a small format synthesizer but never completed this project.

Information and photos for my AVR Synth



Synth Controlled Laser Light Module

My first laser was a modified Ramsey Electronics laser light (LLS1) with CV control of the motor speed.  I built an AVR plug-in that replaces the 555 timers to interface to my synth 5 volt CV levels.  Later I built a full X-Y laser for synthesizer CV control.

Ramsey LLS1 modification document²


Synthesizer Laser²



PAiA Fatman Mods

My son has a PAiA Fatman and we enhanced it with a number of modifications.  Some of the modifications were from various sites on the internet and some I designed.  I consolidated all the modifications into a single document.  Modifications include hard sync, lower frequency range, separate VCO attenuators, sub-octave generators and attenuators, ring modulator and attenuator, LFO filter modulator, and separate VCO tuner output.

PAiA Fatman modification documentation²



Organs, Keyboards, and Amplifiers

 I have information and photos of my various keyboards, amplifiers, Hammond organs, and Leslie speakers.

Info and photos for my organs, keyboards and amplifiers


Keyboard and organ studio layout



Electronic Projects and Restorations

This is my  non-synthesizer electronic projects page.   I have information and photos of two 70's stereos, projects such as an FM transmitter and scrolling display, and various repair and restoration information for amplifiers, speakers, and turntables.

Info and photos for my electronic projects


Info and photos for my electronic restorations and repairs



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