123ADC module project

a thread covering the 123adc if everyone has given it a go or an iteration of it. you can get a 9 bit version by using 2 of the ADC chips



That’s an amazing result from a very simple design. I get a Voice of Buddha vibe there, as if somebody who knew nothing about rhythm deconstructed the sound. Anybody who lives with a parrot will know how “freeform jazz influenced” their sense of rhythm is at times. I’m something of an antifan of synth percussion, but I can see a use for that module in my noisemaking.

1 Like

This is excellent :smiley:

Cant wait to try it. This project has a lot of potential!

any one found the adc0820 in the us or an alternative im coming up blank on getting any thank you for the awesome plans sam

to be honest I plan on building a derivative of this for a module as a first of a few in logic gate functions. I’m wondering if there would be a better alternative from a supply standpoint. a 8bit ADC. people fire away! and ill figure out which is best to use

1 Like

If you’re not in a hurry, you can get 5 from AliExpress for less than $2.50 including shipping.

yea found them from china as well but with chinese new year kicking off lag time is at least a month. i found the smd version on mouser but not sure they will work.

Someone on Ebay has some in Long Beach, California.
For anyone in the US.
They’re kinda pricey, but hey, can have em by the end of this month!

I bought 2!

I picked up some parts yesterday. Didn’t see any of the ADC0820CCN but saw plenty of other ADCs. Was going to see if i could get something working with the ADC0838CCN, was only like 2 bucks.

1 Like

Looks like the ADC0838CCN has a serial interface (MICROWIRE), which means you most likely need a microprocessor to interface with it. Since Arduinos already have ADCs built-in it’s probably easier to just use those directly if you’re going to use a processor anyway.


Mouser has ADC0820CCN… for five bucks each. They have 11 in stock! https://www.mouser.com/ProductDetail/Texas-Instruments/ADC0820CCN-NOPB?qs=7X5t%2BdzoRHD32Kf3FMD5Sg%3D%3D


The stripboard diagram has a different connection for CV In than the breadboard; which is better? I assume the stripboard is more recent.

I’m giving some thought to a version of this for my Eurorack. I’d consider a couple of changes. First, I’m not sure I understand the reasoning for using diodes on each channel; I’d’ve thought one would use op amp buffers instead. And indeed I found the MIDI to Gate module from Barton Musical Circuits, which has basically identical outputs (eight triggers each with a parallel LED) driven from a microcontroller, uses two TL064s or TL074s to buffer the outputs. Second, I’d add protection diodes and 10µF electrolytic filter capacitors near the power header and 0.01µf caps on the power inputs of the ICs. Not sure how I’d build it, stripboard or Adafruit protoboard or the Eurorack protoboards sold by Synthcube (probably would need 2 of those) or bite the bullet and learn how to make my own PC board. Needs further thought.

1 Like

hey just to let you know I have a new version coming out, that is scaled to 1v/octave! it’ll have buffering etc. this ones a rough and ready one with minimum components basically. the diodes were the simplest way to stop the logic LOW. sending things to ground :).


@lookmumnocomputer Any update on this? (Not to take you away from the Delays, as I am excited as hell for that!)

Has anyone actually built the stripboard layout?

I have 2 ADC chips just sitting there lol.

hey! yep. its still here. basically I have a row of breadboards sitting to get transferred onto schematic/stripboard etc. I built the stripboard layout it was the video I did I did the layout then built it to it, it works however I have a much better design now! however that delay has indeed jumped the queue of a few of them of getting from breadboard to the other mediums. rest assured after this im going onto that! as I have finished its dac counterpart too! so I need to be hasty on them :). sadly I cant rush though cus thats when silly mistakes happen


I would appreciate some clean-ish pics of the breadboards if its not too much trouble! :slight_smile:


I just replicated the breadboard layout (which is a little different from the stripboard), no connection to synth just LED outputs, a 555 oscillator for clock, and a pot for CV input.

Seems to work…