An Op Amp Big Muff! With a parallel clean compression circuit! What?!?!?! Amazing on bass. Think I'm gonna have to clone this circuit and mod it for my own design in future.

This thing was sitting in its box in a garage; the owner had long since past and the neighbor was selling stuff off to help the late owner's wife with her bills.

One of the old filter capacitors had tripled in capacitance, so I replaced it to protect the rectifier circuit from potential surge damage when turned on. I am including the original capacitor for good measure.

The circuit has some quirks, for sure. For one thing, this is not a truly clean compressor; the design of the circuitboard (this is revision EH3054) has crosstalk between the compressor circuit and the high gain muff circuit, so it's clearly not designed for compressor-only use. The compressor itself is also fairly noisy--not in a leaky power supply way, but in a thermal white-noisy kind of way. That being said, it absolutely works when used for its intended purpose, which is to blend in some clean signal with the same dynamic compression as the distortion voice.

If I hadn't bought this to repair and then sell to tide me over between jobs, I'd 100% be keeping it for myself. Easily one of the coolest pedals to ever enter my possession.

Comes with original box and papers as shown in photos. Owner's kid must have done a little scribbling at some point. Still cool as all hell.