This is probably the biggest Marshall-in-a-box pedal out there (footprint-wise anyway). Originals use a +/- 12v supply with a transformer internally. I modified the power section with a +/-18v charge pump and will run off a normal +9v power supply. This saves room so you can use a smaller enclosure and gives more headroom to the effect. It is a buffered effect, so the In/Out pads go directly to the jacks. All switches marked in the layout are the footswitches. It should fit fine in a 1590BB with top mounted jacks.
Edit Nov. 28, 2018:
Had 2 pads for the Drive footswitch mislabeled. Fixed now and good to go. Schematic for reference (note the pot lug numbering in the schematic does not follow the normal numbering convention used on this site).
