Rotten Apple

Op-Amp Fuzz (Big Muff v4 style)

Manufacturer description (condensed, with some added notes): The gain of the Rotten Apple has an amazing range on tap, and is sensitive to your guitar, strumming (attack), and volume rolloff. The Tone Control gives you everything from submerged stoner-rock sludge to highs that claw through your speakers.

Extensive testing and tuning was done using an Eric Clapton Strat w/ Lace Sensor pickups. (aka 50's spec Strat Plus.) Knowledge gained from designing the Dark Side fuzz helps reduce the noise while increasing the gain dramatically.

To address the harshness that some V4 Big Muff examples can have, additional filtering was added / adjusted to suit the circuit design.

Knob controls work in a similar fashion to a standard Big Muff, with an additional switch that adjusts the EQ taper from full range, flat, and scooped (from left to right positions, respectively).

https://robertkeeley.com/rotten+apple