Barton Musical Circuits MWC & UWQ Eurorack Modules

MWC Demo 1

Published on Nov 13, 2012 by boogdish

"New prototype from Barton Musical Circuits. MWC = Multi-Window Comparator. Sorry for the blur, I'm working in a basement and the light's not great.

In a nutshell, this looks at your input voltage, converts it into a number, then looks that number up on a data table and turns a +5V output on if the table tells it to. It does this 4 times, for 4 different outputs. There are attenuation and offset knobs for conditioning the input signal, write/erase buttons for writing the "on/off" tables, and save/load and bank select switches for saving your tables to the internal EEPROM.

The write/erase buttons could also be replaced by input jacks so you're rhythm generating devices could write the tables. The board has euro/motm power connector pads. The board has 2 pc mounted pots, and it also has 4 mounting holes so people can feel free to create their own layout. I am going to try to offer a Eurorack front panel for this as well.

I will be writing build documentation for this soon. I'll have boards/PICs to offer for this next month, and a set will be $20 plus postage."

Discussion on Muff's here.

UWQ Demo 1

Published on Nov 13, 2012 by boogdish

"A dry boring demo of the features of a new quantizer module I've designed. More info will be up at www.bartonmusicalcircuits.com after I get it written.

To summarize: Instead of pre-loaded scales/modes, you're using write/erase buttons to create a data table that records all possible outputs, if you saw my MWC demo, this will seem familiar (I actually copy/pasted some of the code).

There are additional controls for: turning the quantizer off, triggering a new sample (it constantly samples when nothing is plugged into this jack), controlling whether the quantizer quantizes above or below the input voltage, a "softness" control which acts like a voltage controlled portamento with fun interactions with the trigger-new-sample control. It can also save two banks of notes onto the internal EEPROM. There is also a bi-polar/positive only switch so it can interact with more voltage sources.

There are input jacks for the quantized signal, a secondary cv (with attenuation pot), external softness cv (with attenuation pot), write and erase jacks for triggering from external sources, trigger-new-sample, and quantize on/off.

Finally, and I didn't get into this on the demo, the board is set up so that the range of the module is adjusted by just a couple of trim pots (an input attenuator and an output amplifier) so individual builders can decide whether they want more range or accuracy. Different people will use this differently so I'll leave it up to them. On this demo I had it set up for 10V range. The table of possible outputs has 1024 parts (because the PIC has a 10-bit ADC), so this gives me 102.4 pitches/octave. At 5V you'd get 204.8 pitches per octave.

This prototype had a few errors on the PCB, so I'm waiting for a revised PCB to show up (should be in the next couple weeks), and if I got all my errors on that, then boards should be available to ship in early to mid January. I think a board/chip combo will be $22. This uses all through hole components, and pc-mounted pots, but has mounting holes so people don't have to use the pc mounted pots. It has euro/motm power connecters and will work with +/-12v or +/-15v with no modification.

I think I'll also be selling a few of these with hand made front panels if anyone thinks this is a cool module but is intimidated by all of the wiring. This is 8HP in euro-rack."

Discussion on Muff's here.