The 360 Vintage Fuzz is based on the fuzz section of the Acoustic Control Corporation Model 360 bass amp and Model 260 guitar amp. This fuzz is footswitchable sub-circuit based on the Mosrite Fuzzrite, but converted to negative ground and utilizing a hybrid silicon/germanium transistor arrangement. Many of the component values are different, but the overall topology is identical.
To best replicate the sound of the fuzz in the original amplifier, we have kept the amp’s input and output buffers intact, which are not part of the original Fuzzrite circuit. We have also ported over a modification from our Orpheus project, which switches in two higher-value tone capacitors for a more modern sound where the original vintage circuit can be somewhat thin.
This project allows you to build either the 360 bass or 260 guitar version, which differs only in one capacitor value. The guitar version has a smaller capacitor going into the germanium gain stage, which raises the bass cutoff frequency and keeps it from getting muddy. The circuit also only runs at 9V since the original amp only used the 24V supply for the input and output buffers, which is in no way important to the sound.