Mdk Mb-17 W Schematic //free\\ -
Unfortunately, finding the official factory schematic for the MB-17 W is like looking for a ghost. But don't reach for the desoldering iron just yet. We’ve done the reverse-engineering legwork.
If you hear a low-frequency "put-put-put" (1-2 Hz) when the effect is engaged, look at the ground plane around the opto-isolator. The schematic shows a missing star ground. Solution: Solder a 10-ohm resistor between the input jack ground and the PCB ground. Mdk Mb-17 W Schematic