Friday, April 26, 2013

Midi2CV module via Midimplant board

UPDATE 8/19/13 -- I'm working on a new version of this module with buffered outputs.  Stay tuned

 This is a module I built based on the Midimplant board.  They are capable of different configurations which you can upload via midi Sysex.  The website has a configuration widget here, which makes things incredibly easy.  One of these options will convert midi to CV and Gate signals for 2 independent midi channels.  My eventual goal is to have a 4 channel midi to CV module, so I hope to be getting another board when they are available.  With that in mind, I designed the module and the PCB to be ready for my future configurations.

Here's the board. I soldered a header on it, to make it easy to play with.

Here's the pinout.  Something to keep in mind, is the gate signal is whatever the Positive voltage input is.  my system is a standard Synthesizers.com/motm +/-15V.  All my modules seem to work fine with 15v gate, so I didn't really worry about adding a voltage regulator, but it would be easy to implement if that was a requirement. 



I like LEDs on everything.  Why else build a big monster synthesizer if it's not going to be covered in tons of blinking lights.  I added simple 3904 LED buffers to the circuit aswell. 
I didn't do a schematic and I didn't label the pads on the parts picture either but I will name the now. 
It's clear where the chips go. the chip should be facing you. 

LEFT SIDE of the PCB
 Midi input (pin 4 and 5 on your DIN jack) it doesn't matter which of the 2 pads on the PCB. 

RIGHT SIDE of the pcb
(from top to bottom)
CV2
LED2
GATE2

Gate1
LED1
GND
CV1

(chip 2)
CV2
LED2
GATE2

Gate1
LED1
GND
CV1

It should be set up so that the thru is already connected correctly to the second chip's midi input, but I am unable to test this because I only own one chip currently.  You will need to configure the chips seperately using the first chip socket.

The artwork from this module is a nod to Twin Peaks.  I also did a front panel design. 


I use a more diluted mixture of Ferric Chloride for etching Aluminum. basically I mix in the same amount of water as etchant (I got this etchant at radio shack).  I have no idea if etching aluminum is toxic or not,  wear a resperator if you are considering this.  I leave it in there for about 5 minutes. 

2 comments:

  1. Very cool! If you made the panel and PCB available for sale, I would surely by them. Nice Twin Peaks reference on the PCB, too.

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