DOD - FX76 Punkifier [schematic]

[mirosol]

The previous topic on this unit has practically zero informational value, so i though i'd start a new one.
(previous one, in vintage section, is here: https://www.freestompboxes.org/viewtopic ... 76&p=43516 in case admins want to remove it - along with this line...)

Got mine a few days back and i really enjoy the sound. Sort of like Devi meets Boss. While the design seems to be nothing more than a buffer/splitter -> fuzz section (weirdish, original design) + distortion section (OD250 on steroids) -> sections blended together -> buffer -> active treble boost -> output buffering, it sounds very good and there's something personal to its sound. These are getting rather rare and the prices are also getting rather steep.

Snapped a couple of photos of mine today. Thought about doing a re-trace as i believe the floater schematic has errors on it. I've attached that too (apologies to the copyright owner). To begin with, there are couple of smaller errors on the input buffer alone. Plus the resistor numbering is a pain to read since most labels are under the components. Since it started this way, i decided to leave the re-tracing for another day.

All 100k pots are W-tapered and the 500k is reverse log. Both opamps are KA4558s and there are three types of transistors on board. J201 JFETs, 2N5088 BJTs and MPSA12 Darligtons. So there are number of things wrong with the floater. It may have most of the base topology correct, but i'm not even certain about that in this point.

Due to scracity and rocketing prices, this may be a nice thing for cloning. Just wouldn't want to build one from a schematic that doesn't work. That's all i have for now. All input is welcome.

[astrobass]

Yeah, like Devi ever figured out how to implement an op amp

The Punk control is neat. The signal splits into a mu-amp on one side and an op amp on the other. Each one hits an identical set of clipping diodes (to ground, not neg feedback), and the Punk control is a blend between either side.

Looks like there are two spots where it's using op amp rail clipping to add to the distortion. I'm guessing this is almost unusably loud.