This is a 6 voice analog drum module based on the Boss/Roland DR110. I saw this thread over on Mod wiggler. It looked like a fun module that I could get some use out of. Weston Audio has a few interesting Eurorack modules. They offer the AD110 as a kit!
The kit comes with three PCBs, an aluminum front panel, and 4006 shift register chip. The boards are great quality and well marked. The front panel is particularly nice. The documentation is pretty good. There are lots of parts spread across three boards. Luckily the part numbers are number well 1xx for board A, 2xx for board B, and 3xx for board C.
This is a fairly epic project. It’s three bards all through hole parts. Most of the parts are easily available. There a few things that are harder to get. The parts list show more than a few resistors as 0.1% tolerance. These are harder to get but available through Mouser. The hang for me was not all of the values were in stock! That’s another point, som of the values are very specific like 374r, 91k, 158k etc. I had many of the values on hand but there was I lot for this project that I didn’t have.
I ordered parts from mouser and Tayda Electronics. It probably cost me roughly $100+ more for parts. That will put this project in the $150 to $200. Which is about half the $385 asking price for the pre built version. Sometimes you want to be careful with DIY. There are occasions where it’s more cost effective to buy the prebuilt version!
I made a couple part substitutions. There are some diodes listed as ISS133M. I looked these up and it sounds like these are general purpose diodes, I subbed with 1N4148/1N914 types. I also subbed the ferrite beads with the closest equivalent I could get from Tayda.