Another great contribution by Chris Stelloh!
This is a layout drawn from the Madbean Oracle project, which is, essentially the Boss CS-3 compression sustainer. I really like the sound of VCA-driven compressors, especially on sampled drum sounds. This Boss pedal has been around for about 40 years, and the Madbean version makes a few slight modifications to it based on stuff people have done attempting to improve the sound quality and lower the noise. I included a list of part values that are most commonly swapped to make this more bass guitar friendly.
This one is verified and good to go.
To anyone who may attempt this one - the 8 pin SIP chip (I used the Coolaudio reissue) has a flat side and and an indented side. With the indented side facing up, the pins are numbered 1-8 from left to right.
ReplyDeleteThanks for the hint, I definitely need to source one, thanks for the layout.
DeletePs in the upper left part of the board, 4x 100nF in // = 400nF no?!
The power filtering MLCC's are in parallel - so yes, approx 400nF. The four individual caps are what is on the schematic. https://www.madbeanpedals.com/projects/_folders/Compressor/schematics/Oracle24.gif
DeleteAlso - as far as the various 2181 SIP chips go - THAT makes three of them with suffixes A, B and C. Fidelity according to price - "A" is the most expensive at about $11. The coolaudio one I used is the least expensive at about $5 - and I don't know how it compares to the others with noise floor and all. This can be a bit of a noisy bastard when you crank the sustain, and a gate after it can be quite necessary for some applications. I will be sending Anders/Fuzzhead a layout for a modified NF-1 noise gate that I am currently working on verifying.
ReplyDeleteAmazing! Thank you Chris!
ReplyDelete