freestompboxes.org

I continued my Exar circuits tracing, this time it was Exar MM-04 Moon Metal. This one was a recommendation by some of my FB friends and I was lucky to get it recently from Germany for a decent price. It is the last Exar series 4, made in the early 2000s.
The PCB is single-sided, the only challenge was measuring pot values, as they are placed on a separate PCB and wired with "spaghetti" to the main board.
Surprisingly it appeared to be a modified Marshall ShredMaster with input/output buffers added (mainly for non-true bypass switching). The main difference is in a few gain stage values and EQ (Low/High part) and gain of the output stage (I double-checked those parts). The pedal has a ton of bass on tap and lacks treble a bit IMO (I would add a kind of presence control to it), but still sounds pretty good. I don't have ShredMaster and haven't built one, so can't compare it, but changes in EQ are quite big according to the tone stack calculator. Attached is the schematic with bypass switching circuity omitted.

Now this could be a decent thing to play around with.
Here's a stripboard to try it out..
+m