The first stage is bypass, which is very much similar to the Jumbo Tone bender. There is volume loss on this stage but has a very nice sound and probably more suited for bass.
The second stage is the fuzz war stage, this is the more familiar fuzz sustaining tone
The third stage is the Reverse Beta stage, similar to the fuzz war stage but with the transistor in backwards and more harmonic content.
The fourth stage is the similar to the previous two but uses a dual op-amp to get the sound, its similar to a band pass filter.
The fifth stage is the octave stage, transformer based octave with an internal trim pot to adjust the gain for this stage. Lower gain settings for this sound more musical, and sounds best with single notes not chords.
The sixth stage is the gainiac stage, it has an internal trimmer to adjust the gain of this setting as well. Set it to the max for a crazy speaker ripping sound.