The Antipode Vintage Fuzz is an adaptation of the Roland AF-60 Bee Gee, a fuzz/distortion from 1975 that is best known as the standalone version of the “jet mode” of the legendary AP-7 Jet Phaser.
It features a combination of transistor gain, op-amp gain and diode-based hard clipping to get its character. The tone control is the classic Big Muff “balance” style, centered around 1.3Khz with a very slight mid-boost in the middle position.
The Jet Phaser’s adaptation is largely the same but with fewer controls. The output volume control is retained for the fuzz stage, but the tone control is simplified into a two-position switch with only “full bass” and “full treble” settings. The potentiometer on the AF-60 is much more usable.
The Antipode project has one modification, which is the addition of a gain control to allow the distortion level to be dialed back. In the original, the op-amp gain was fixed at 220, but with this control it can now get as low as 2, getting down into overdrive territory instead of full-on fuzz. With the gain control at maximum, the circuit is 100% identical to a vintage AF-60.