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BugBrand Modular Synth
Click on some of the pictures to launch bigger versions.

Please note that this system has been put together as a way for me to experiment and learn.
So mostly the modules aren't aiming to be available commercially, although they may filter through to new Bug devices...

June 08 - Some sounds:
It has been about 3.5 years since I released any Bugs recordings proper - the modular provides audio clay which doesn't lend itself to songs or such, so most 'documenting' recordings I've done have just been long free runs. I don't feel like editing these on a computer and, actually, the way they flow is interesting as is. So, here are some, warts and all - there'd be more but I lost a whole hard-drive with all of last year's recordings by dropping it on the floor...
All these tracks are recorded in mono straight from the modular output. A small amount of EQ and compression has been applied in software, but that's all...
Note that they're quite large files - I'd recommend downloading them and then burning to CD so you can take them away from your computer. For best results play on a system which can produce decent bass.
bbef - quite beat driven - from Mar08 - 12 mins
extraday - slow beatish - from Feb08 - 16 mins
highandlow - slow moving extension top and bottom - from Mar08 - 23 mins
lows - bass hits with crunch - from Mar08 - 6 mins
morehi - swirling hi frequency modulation - from Mar08 - 20 mins

Click to enlarge

News Mar08:
Though this page has been a bit sleepy, there's still been plenty of movement in the workshop!

This is the new portable suitcase modular frame just completed. Well, the frame is completed, but the modules are always being changed as things are updated and tweaked towards the never-attainable-perfection!

This will be the sytem for shows around Europe this summer.

Click to enlarge

News Aug07 :
Another month, another modular frame...

I've been building up to a fully solar powered portable modular system over the last few months and finally the frame is done. Built to measure, the frame holds two rows of 26 Frac-width modules giving a whopping total of 52 units! And there are two large solar panels housed in the lid which hook up to 12v SLAs / charge controllers to provide all the power without any mains requirements.

Ambassador Rack - Jul07

Porta-frame - Jun07

Recent News - July 2007:
Here are some updates and images of how my DIY modular has been growing - there have been quite a few new modules to slot in. I've been trying to get things more portable for live use and also thinking about power, especially battery / renewable. As the configuration of the modules will continually be changing, its important to look at making some decent frames that offer a form of housing, power, auxiliary functions, etc.

I've got two systems going at the moment. The first & main one is the Ambassador Rack. This is based on a large mixer/effects flightcase - three fracraks at the top and a bunch of rack space at the front. Unfortunately there's a lot of dead space inside and, due to size, the whole thing is pretty awkward.. But, there's space inside for two large lead acid batteries (2x 12volt 7Ah) to provide several hours of portable use (solar powering to be developed..). At the front there's an input mixer - four preamps and various aux sends that allow lots of routing - both to external effects and for passing sounds in the modular system (..via some internal wiring buses). The main output has an opto-compressor on it and then hooks straight into a 20watt power amp - connect a hifi speaker and, with the batteries fully charged, you can get many hours of completely portable modular noisings. There are some more details on the BugBlog and pics of the current module arrangements below - Ambassador Rack details.

The Ambassador is too big to take on a plane, though. I had an old just-about-rack-sized box hanging around, so I chopped this up a bit and added rack rails for two fracraks and an (almost) 2u auxiliary panel. This Porta-frame fits within the size limitations for carry-on musical instruments (certainly on Easyjet which states 30 x 38 x 117 cm as the max allowable size) - I took this case to Europe as hand luggage without any problems at all! This runs again off two lead acid batteries. The aux panel features preamps, inverters, mixers etc. There are some more details about the frame on the BugBlog - here and here.

BugBrandModular - Mar07
BugBrand Modular - Mar07

BugModular PortaPair
PortaPair - FracCase & Drone Machine

Recent News:
March 07

Work on the modular goes in fits & starts - everything was dormant for the first couple of months of the year, but then I got active again in March, trying out new ideas and working towards some live performances. I've come to love this system for trying things out - both in a sonic way (so many possibilities) and for working out circuit designs.

I've got portability in mind a bit because I do aim for live use, but a system like the one pictured on the left will never be able to travel far! So, working on from the recent Drone Machine, I've made a further case that has a 7 unit Frac-frame within - ie, a reconfigurable portable modular case. And its got a super-fun stylus keyboard outputting standard 1v/oct, gates, triggers and envelopes - more details of the Stylus Keyboard Case here.

Live visuals have also been on my mind and really spurred on by the Oscillographics project - an electronic spirograph circuit that creates beautiful drone tones and, when hooked to an oscilloscope, generates immersive lissajous figures. This looks really fantastic projected onto a big screen.

Other new additions include Env Generators, updated BugCrusher module (does great S/H modulation waveforms and is very versatile), Buchla Low Pass Gate clones, Audio Interface module, ISD lofi sampler prototype...

Modules & Racks:

Other details:

Ambassador Modules Jul07

  • VC Clock - an old module from a Synapse design
  • CGS Divider x 2 - two dividers offering clock divisions of 2/3/4/5/6/7/8 plus reset. Based on the CGS Pulse Divider.
  • 10 Step Dual Gate Sequence - inspired by the CGS Gate Seq but maxed out to 10 steps - the 4017 chip that drives this circuit is meant to count to 10 and such a setup gives you just that bit extra over the standard 8 steps. It was a real squeeze to get four pcbs in - one for clocking / counting, two boards of switches (much more compact than using panel mount switches), and one board of LEDs. Each column offers gate or trigger output - the gate will stay high on subsequent ON settings whereas in trigger mode you get an individual pulse for each switch that is on.
  • Dual Pattern Generator - have a check of the project for this on the electronics page
  • Dual AR Envelope Generator - DIY design for simple but effective envelopes
  • ADSR Envelope - I think this was an MusicFromOuterSpace design but can't quite remember....
  • Touch Control Interface - inspired by a session at Steim with Michel Waisvisz. More details coming soon... this connects to an external box with 9 touch points - four source signals and four desination outputs plus LEDs for each and a ground connection. Lick your fingers!
  • ISD Lofi Looper - experimental and still slightly bug-ridden Lofi Looper using the ISD1416 chip.
  • Thomas Henry Quadrature VC(LF)O - new quadrature VCO by Thomas Henry. Details on Scott Stites' website. This offers four tri waves each - 0°, 90°, 180° and 270°. Great for modulations!
  • Thomas Henry XR2206 VCO x2 - a great TH design that's online at Scott Stites' website plus I have a compact PCB image for it on the electronics page
  • Thomas Henry / MagicSmoke Mankato Filter - maxxxed out Mankato VC Filter from MagicSmoke. This Thomas Henry design also acts as a sin oscillator with an extremely wide range from super low freq LFO to oscillations above human hearing - and you get eight individual outputs, each one 45deg out of phase and attached to bi-colour LEDs for mesmeric lighting effects..
  • Noise Generator & Ring Modulator
  • BugCrusher - this design is still changing but currently offers two rates - audio rate for sample-rate-reduction effects or mod rate for low freq clocked waveforms (like a standard S/H module). Also has external clocking possible.
  • Lo Pass Gate Clone
  • PS3100 Resonator (FonikModular) - great sounding clone project pcb offered by Fonik Modular
  • VC Vari-state Filter
  • VC Delay PT2399

Stylus Keyboard & Frac-case

Frac-case with Stylus Keyboard

More portable power built into a similar case to the Drone Machine.

Keyboard part - this is a Music From Outer Space design for keyboard controller with various additions and using a simple stylus keyboard (3.5 octaves) instead of a normal synth keyboard. The keyboard outputs standard 1v/oct CV info (there are two CV outputs, each with independent glide, plus CV2 has various shifting / offsetting controls). Trig and gate signals are output and the trig is also used to generate two simple drum style vari-decay envelopes. To use up panel space I added some footswitch modules and a passive output for general use.

The box also acts as a frame for 7 fracrack modules, so I can change the configuration - in the picture you can see i) proto ISD VC Sampler (lofi!) ii) PS3100 Resonator (Fonik design) iii) Oscillographics module.

YouTube demo video using the keyboard


This is built from a project from 1978 published in the German Elektor magazine.

Its like an electronic spirograph that generates dampened sine-waves that you plug into an oscilloscope to produce ever changing and immersive Lissajous figures.

Project details on Electro-Music DIY Synth Forum

YouTube video demonstration


More new developments - there's never enough space..


Env Gen - Music From Outer Space design - retriggerable with State Indicators

Modular Gristilizer - the legendary Throbbing Gristle effect modified into modular form from an old Practical Electronics article.
The lefthand side is a VC-LFO with ramp up/down, triangle and square waveforms. The righthand side is a VCA / VCF with biasing control - the input of this part is very gnarly so you get a very characteristic and lofi'd sound out.

XR2206 VCO - Thomas Henry design based on the XR2206 oscillator chip - pretty simple yet really powerful - includes linear and exponential frequency modulation, sync and a wonderful skew effect that morphs the waveforms. Provides pure sinewaves, tri and square. Also modified so as to work as a VC-LFO.


The AudioRak has been re-arranged and updated.


PreAmp and Env - Audio input plus envelope follower and trigger generator

Steiner Filter - Built from the Ken Stone plans. Lovely resonance ringing.

Wasp Filter - From the Juergen Haible plans.

VC Rate Reducer - prototype for the mighty BugCrusher pedal - an audio rate sample & hold amp that provides an effect like a bit-crusher. Based on the AD781 S&H chip.

Quad VCA - Four independent VCAs with Lin or Log response built from a Music From Outer Space design.

Mixer - A simple 3 channel mixer with an Attenuverter (A Cram design) tacked on the end.


This will mainly contain modulation sources and utilities - though at the moment it holds the Drone Machine.

I got this rack off Ebay - its the standard for Doepfer modules and holds 84HP width of modules. I kind of prefer the standardised Paia Frakrak method though - keeping all modules a similar width.


Dual LFO - Taken from Test Box 2 - two independent Sqr / Tri waveform oscillators with 3 ranges going from super slow to audio frequencies. This is a standard & simple design offering varibale waveshape / pulsewidth.

Dual Sample&Hold - two simple but effective independent S&H modules.

Noise & RingMod - the noise was taken from the defunct TestBox2. RingMod is provided from a simple circuit based around the AD633 chip

Quad DC Mixer - Four powerful little DC mixers primarily for mixing control voltages. Each mixer offers a summing mixer with offset combined with an Attenuverter (an A Cram design).

8Step Sequencer - Ken Stone design - the switches are on-off-on types so there are two channels of triggering.

Dual Glide - takes a square waveform and smooths the changes with independent Attack Decay settings.

Control Rack:

These are all built into one of the FrakRaks - these each fit 10 modules across and I've used sheet aluminum for the frontplates because its quick & easy to work with. It does all look a bit rough around the edges, but it works just fine.

This rack currently runs at +/-12v but may be converted to standardise it to 5v trigger / gate operation.

Foot Control - Having foot control is really important for me (playing guitar etc.), so I designed this footswitch interface and hacked on a glide function from a Music From Outer Space circuit. This is a quad version and each channel has input for a standard momentary footswitch on 1/4" jack plus a panel mounted duplicate. There are two switches that select how the momentary footswitch behaves - offering Normally Closed / Normally Open and Toggle. The glide circuit gives a maximum rise/fall time of a few seconds.

VC Clock - This is the heart of the Voltage Controlled Event Arranger circuit from Synapse Magazine and works well as a stand alone circuit.

Divide 1 - A slightly trimmed Master Divider circuit from Ken Stone. Divides a clock by 2/4/8/16/32/64 with normal and inverted outputs.

Divide 2 - ...not quite working correctly yet (but still useful as it is..). A Ken Stone circuit that divides by 2/3/4/5/6/7/8.

Logic - Ken Stone Boolean Logic circuit with 2 AND, 2 OR and 4 Inverters.

Power Supply - this rack runs off an AC wallwart adaptor at the moment and has a simple but effective power supply and distribution circuit mounted inside. Power comes in at the back and on the front there's an easy on-off switch, power indicators and a common ground connection that will be connected with other racks.

Drone Machine:

This module is still in quite early development stages - circuit re-designs going on now... The module has been taken out of the rack until its insides are improved..

The Drone Machine is built around four lofi oscillators which can be fed back into one another to create a system of constant shift and chaos.

Each oscillator, running at audio speed or low frequency, has simple waveshaping to smooth its squarewave output towards a triangle shape. Pitch and tone/shape can both be CV modulated and each have their own modulation depth control. There is also a keytrack control for the waveshaping. All controls are driven by Vactrols - little couplings of an LED and LDR. The intensity of the LED light sets the LDR resistance and this variable resitance is used to control a function within the audio circuit.

To keep the oscillator designs simple (ie. not having to build four proper ones) a single chip (CMOS 40106) is used to produce all four oscs (there are actually two further oscs left unused..). As the oscs are all on one chip a low-power circuit bend can be used to retune all the oscs together. This control works out to be pretty messy - it is basically starving the oscs of power so they tend to behave in wierdy ways.

A mixer that sums all the oscillators is still to be added. LEDs will also be added to show how fast each oscillator is running. This module could certainly expand in future designs - more oscs, more modulation inputs..

Test Boxes Modules:

I had a few old metal boxes hanging around (from old logic tutor boards) measuring about 20 x 28cm and with removeable aluminium front panels. So I cut some aluminium sheets to size and set about enclosing my first modular circuits.

I've used 4mm banana plugs for all the connections within the synth - these were chosen because they're pretty reliable, compact, and its so quick & easy to make new cables. They're also stackable and the plugs are available in many different colours - so I've got CV inputs as blue, CV outputs as red, Audio inputs as yellow and Audio outputs as green.

Box 1 - sound sources and processing

2 x VCO - Soundlab design
VCF - Music From Outerspace design
Dual VCA - A Cram design
VC Delay - a Scott Bernardi design (using the PT2399 digital delay chip) with custom modifications for VC Modulation

Box 2 - CV sources for modulation - !this box has now been dismantled! - some of the circuits have been rehoused into the racks and the box will be reused at some point.

Noise / S&H - Digisound design
Joystick Controller - Custom design for industrial joystick control
ADSR Env - Modulus design
2 x LFO - simple standard design with variable waveshape
Gate/Trig Converters - various designs (not pictured)

Box 3 - interfacing to/from 1/4" jacks and audio processing

3 x Preamp - modified Craig Andertron design
2 x Attenuverter - A Cram design
Freq Divide - Blacet design (not pictured)
Ring Mod - Digisound design
2 x Audio Mixer - standard design


  • The system runs at +/- 12 V. Each rack has a power board that produces a stable bipolar supply from a 24v AC wall-wart adaptor. The board also dristributes the power to multiple sockets that allow quick connections for modules.
  • All connections within the system are on 4mm banana jacks - its so quick to make the cables, they're cheap, available in many colours and you can stack them (..but, you don't get the power of normalisation that jack plugs would allow..).
    The colour standard throughout is: CV In = Blue, CV Out = Red, Audio In = Yellow, Audio Out = Green. Each rack also has a common ground connection.

Groove Electronics M2CV

A really damn useful MIDI to CV converter picked up for only about £40 off Ebay (probably because its not a well known make?). This is one of the versions with a bunch of extra features - there are two channels of MIDI to CV, each with independent Pitch CV, Control CV and Gate (on 3.5mm plus, but I've made a set of adaptors to 4mm banana). It's possible to get crude duo-phony by setting the two converter channels to receive on the same MIDI channel and setting the respective triggering priority. Plus this version has an Arp output that syncs to MIDI clock - ideal for syncronising the Control Rack to MIDI machines.


Modular Gristiliser Demos - pretty rough'n'ready demo-sounds - first one is with guitar, second one with XRVCO.
Gristle1, Gristle2

Sounds using the Control Rack for rhythmics and modulations, plus the M2CV for MIDI control. The first four minutes are a cut-up of various wierdy, all-over-the-place sounds and then it clicks into a rhythmic wonky techno sort of thing..
7 minute chopped together demonstration (mp3 - 6.4MB)

A quick burst of demonstration sounds from the Test Boxes:
Deep Synth Sounds, Delay Hyper Mods, Guitar Chop, Guitar Delay Decay, Guitar Under Bubble, Hi Bends with Filter
Modular Feedback Filter, Moving LFO, Regular Rhythm Delay Mod, Rising Harmonics, Synth Line, Tune Noise, Whistlee

And some sounds with new developments - lofi loop sampler and Wasp filter:
Looper Guitar1, Looper Guitar2, Looper Guitar Short

Archive Images

BugBrandModular - Oct06 BugBrand Modular - Aug06