Monday, May 6, 2013

Live set from Landscrape, Chicago 4.20.13 + Facebook page!

I've been sorely neglecting things in blogland but hope to pick up a bit once more. I've also created a new Facebook page here for my modules, pedals etc. For now, enjoy one of my live sets from Chicago recently. Lots of good live analog gear used: Roland TR707 Roland TR606 Electron Analog Four Sequential Circuits SixTrak MXR Pitch Transpower Roland DC-30 Narrat1ve WTPA 2.0 Modular Synth

Monday, April 30, 2012

Loft - The Package

We just finished up a new record today.  Music recorded with our diy modular synths in several cities around the world.

Friday, April 20, 2012

A New Face!

Another panel option for the Voice of Saturn Synth "Red Devil" Euro module.

Thursday, April 12, 2012

Big Muff Mod!

Last week I did a simple Big Muff mod for a client in the band swerve. Its one of the newer, surface mount pcbs, and thus took a little digging around the circuit to find the correct place to implement the noise gate mod described here. Its pretty easy to figure out which transistor is the 2nd gain stage from looking at the stock schematic from general guitar gadgets, then it just took a bit of poking around to find the equivalent to R14, the 100k to ground. I used a 500k linear pot instead of a trim pot, to allow the user to dial the tone in to taste. Its a pretty easy mod, and super useful as are the others on that site. I hope to get a cheap newer big muff in the near future and fully mod it out.

Wednesday, April 4, 2012

Arduino Midi to Trigger interface with random cv output

Today I completed V1.0 of my Arduino Midi - Trigger interface. Its nothing groundbreaking but a very useful module to give you up to 9 trigger outputs, a random cv output, clock input and midi control over all inputs. The inspiration for mine was watching some demo's of the amazing drum dokta module from Din Sync. I picked one of these up and they sound killer but I needed a useful and easy way to trigger the sounds. The module is basically 2 parts. One is a clock divider inspired somewaht by the 4ms module, the other is a simple midi implementation. As it stands, triggers 1-6 as well as the random cv trigger are controlled by midi notes 60-66. This is easily editable in the code and more triggers can be added. Below is a diagram of the connections and the code follows. Hopefully someone will find this useful and help me to improve it!

One other important thing to note, this program uses the Arduino Midi library which can be found here.
Code below:

#include "MIDI.h"

// Modular utility controller
// Clock divider, random CV generator, Midi to trigger
// Rev 01. 4-2012 Travis Thatcher

// midi values
#define OFF 1
#define ON 2
#define WAIT 3

boolean DEBUG = false; // to turn off all debug print messages

int resetPin = A0; // analog input used for reset button
int resetValue = 0;
int resetStart = 0;
boolean resetState = false;

int pwmPin = 5; // pin to output cv
int sequence[16]; // array to hold sequnce for pwm out
int counter=0; // counter for pwm sequence array

int triggerPins[] = {2, 4, 10, 11, 12, 13}; // trigger pins
int triggers[] = {0, 0, 0, 0, 0, 0}; // hold trigger counts
int triggerDivs[] = {4, 8, 1, 2, 16, 4}; // these set up the clock divisions for eachoutput
int triggerTimes[] = {0, 0, 0, 0, 0, 0}; // hold times for triggers
int triggerStates[] = {LOW, LOW, LOW, LOW, LOW, LOW};
int triggerTime = 1;

int currentTime=0;

byte incomingByte;
byte velocity;
int action = 2; //1 =note off ; 2=note on ; 3= wait

void setup() {

MIDI.begin(2); // i need to use channel 2 since i use the midi thru to send data do my doepfer midi to cv on channel 1
randomSeed(analogRead(0)); // lets get random
// setup output pins
pinMode(pwmPin, OUTPUT);
pinMode(2, OUTPUT);
pinMode(4, OUTPUT);
pinMode(10, OUTPUT);
pinMode(11, OUTPUT);
pinMode(12, OUTPUT);
pinMode(13, OUTPUT);
resetStart = millis();
attachInterrupt(1, trigger, RISING);


void loop() {
if ( { // Is there a MIDI message incoming ?
switch(MIDI.getType()) { // Get the type of the message we caught
case NoteOn: { // If it is a note on


//Handle reset processing
resetValue = analogRead(resetPin);
currentTime = millis();

if(resetValue >= 200){ // arbitrary, just making sure the button is pushed. anything greater than 100 would probably work

if(resetState == false){
resetState = true;
resetStart = currentTime;
else if(currentTime - resetStart>=200){
resetState = false;

// check out the trigger states
for(int i=0; i<6; i++){
if(currentTime - triggerTimes[i] > triggerTime){
Serial.println("turning off!");
digitalWrite(triggerPins[i], LOW);


void shuffle(){
for(int i=0; i<16; i++){
Serial.println(sequence[i], DEC);

// reset beats

for(int j=0; j<6; j++){
digitalWrite(triggerPins[j], LOW);


void resetBeat(){

void trigger(){

analogWrite(pwmPin, sequence[counter]);
if(counter == 16){
counter = 0;

//trigger outputs
for(int i=0; i<6; i++){
digitalWrite(triggerPins[i], HIGH);
triggerStates[i] = HIGH;
triggerTimes[i] = currentTime;


void playNote(byte note){

// funkee random bits
analogWrite(pwmPin, sequence[counter]);
if(counter == 16){
counter = 0;

// triggers!
for(int i=0; i<6; i++){

digitalWrite(triggerPins[i], HIGH);
triggerStates[i] = HIGH;
triggerTimes[i] = currentTime;
action = 2;




Thursday, March 29, 2012

The Voice of Saturn Synth, Eurorack module!

Finally finished the first actual production VoS Synth euro module. I have a very limited number available at the moment, with more coming hopefully later this summer. This first batch is handmade by myself and is a bit cheaper since the panels were messed up slightly in fabrication (the top mounting holes are about 3mm too low, thus I had to route the holes out to make them bigger.

Its the same circuit as my previous synth, but its really interesting to use within the context of a modular with all the cv possibilities. The video pretty much demonstrates the range of sounds and modulations. Panels, pcbs and vactrols are available from Curious Inventor. I have some built modules for $220, get in touch if you are interested.

Wednesday, February 22, 2012

DJ Mix and VoS Synth status

So I've got the Mouser BOM ready to go for the Euro-VoS Synth. Should have the panels within the next two weeks. This first run is a small one so there will be about 10 or so available from Curious Inventor as part of a package that will include the PCB and a vactrol (since they are a pain to find sometimes). I'll personally be building 10 modules that will be for sale by mid April (I hope). If you want to reserve one the cost will be $220 + shipping. You can email me: recompas at gmail dot com to reserve one if you'd like.

Now for a mix I made today:

Wednesday, January 25, 2012

Voice of Saturn pcbs back in stock + euro panel coming soon!

We've got the original Voice of Saturn synth pcbs back in stock over at Curious Inventor. I've also designed a Euro-rack panel which we will have in stock within the next 6-8 weeks. This summer I hope to have some new Voice of Saturn designs going into production as well!

Sunday, November 20, 2011

Balboa - Live at Zebulon 11 16 2011

Balboa - Live at Zebulon 11 16 2011

Here's our live set from the other night in Brooklyn. We used an Arp 2600, Moog Little Phatty, Realistic (Moog) MG-1, Roland TR-606, my diy modular, and some computeres to send out the midi sequences (all audio signals are analog).

Thursday, November 10, 2011

Its been a minute!

So I've been on the road since the beginning of September and have been neglecting the blog. I'm in Kiel, Germany at the moment and am looking forward to some electronics projects waiting for me when I return. For now here are a few webcasts from myself, Nathanial Murphy and Mikael Jorgensen. The first is from a hotel room in St. Louis on Oct 3rd, 2011. The second is part of a larger live jam on Nov 6th at Plattfon Records, Basel, Switzerland. The linked video is mainly us, but then the third is any number of people who came along and brought some toys.

Monday, August 22, 2011

VoS VCF pcbs/panels/cem3372 chips for sale

We've got a few CEM3372 chips, filter pcbs and panels that we'll be selling together on Ebay in the next week or so. This is the last remaining stock (apart from a few I'm keeping for myself).

Via this Ebay auction.

Saturday, August 20, 2011

Curious Inventor's VMeter Test

Sorry for the low volume on the voice-over. Here's a quick demo of CI's VMeter. Pretty useful little midi tool, and who doesn't love nice bright blue LEDs? More info here.

Sunday, July 24, 2011

Casio CZ101 Backlit LCD Mod!

A client gave me a CZ101 with a dead LCD to work on. I replaced the former with a new backlit LCD from Sparkfun. They're cheap and come in a few different colors and being able to see the screen in the dark is totally key. The mod is super easy, just one note - the pads for the backlight power just need to be connected to the LCD power, and the rest of the wires go in the same order as the old display but the pads themselves will be on the other side of the board - i wired mine upside down at first. Get in touch if you want help doing this mod, or would like me to do it for you!

Friday, July 1, 2011

Voice of Saturn Sequencer clock IO mod

A while back I was syncing my VoS Sequencer to midi via the clock out of a Kenton Pro Solo and noticed that the clock was slightly off. I remedied this by using the gate out and shifting the notes of a midi sequence until it locked in but realized this was a problem. I discovered that the decade counter that is the heart of the sequencer is triggering on the trailing edge of the square wave of the clock instead of the leading edge. This means that if you try to either sync to an external clock or send clock out, the sequencer will be half a step out of sync. Granted, this can be kind of cool for off time stuff and you may want to do the following mod so it can be switched in and out. The idea is to put an inverter between the clock and the clock jack so the output clock signal is inverted. That needs to go through another inverter before it reaches the decade counter so the clock signal ends up as it was before. This 2nd inverter will also invert an incoming clock signal so things will sync up. I've done this mod on a few and it works fantastically. Attached is a schematic.


Wednesday, June 29, 2011

Last Voice of Saturn Sequencer MK I

First come first serve. I've got one more enclosure for the last built (and signed by me too) voice of saturn sequencer. $400.00 There's still some pcbs left for $35.00 each. Within the next year I hope to release a completely different sequencer but for now this will be the end of the run. Email me: recompas at gmail dot com if you are interested.

Sunday, May 15, 2011


Here's a new piece I just recorded for a fashion installation.
Sndtrk by recompas

More info on the patch etc. on patchatoms

Friday, May 13, 2011

Urban Remix Times Square Performances

Yesterday I did two performances in Times Square as part of the Urban Remix Times Square project. The first performance took place outdoors in the square, the second in the Times Square visitor's center in the evening. It was great to see the typical visitors to Times Square react to our performances. We got a lot of positive feedback. I was also very interested to see what I would come up with for this project, having performed a piece for the Atlanta Beltline Urban Remix last year, I really enjoyed the contrast in source material. All sounds on these recordings came from recordings made in Times Square, no additional synthesis or sampling is in there, just filtering, compression, delay, re-arrangement, etc. A little musique concrete.

Urban Remix Times Square 5.12.11 perf 1 by recompas

Urban Remix Times Square 5.12.11 performance 2 by recompas

Thursday, May 5, 2011

Modular Recording

Here's the recording we made on the gear pictured in the previous post.

Loft- Untitled 2 (collaboration with Recompas/Voice of Saturn) by alter/break

For more info check out at PatchAtoms.

Monday, May 2, 2011

Modular Madness at SAIC

Modular Madness at SAIC, originally uploaded by recompas.

Recording coming soon! Got a chance to play on this with my co-conspiritor in loft

Tuesday, April 19, 2011

Voice of Saturn II

Voice of Saturn Synth II Prototype from Travis Thatcher on Vimeo.

Here's a quick demo of the mostly completed prototype of the Voice of Saturn Synth II. Its actually going to be a sort of modular oscillator system, with a circuit board for each vco, and a mixer board. This will allow you to have 1 - ? VCO's depending on what your space requirements are. My prototype will eventually have 5 VCO's, and 2 will have caps for super low speed LFO timing. Once I get the pcbs prototyped and working, I'll be doing a Kickstarter campaign to raise funds for the first board run this summer.