The first printed circuit board production models carried over the core 1969 design with slight changes, likely due to parts availability and standardization.The 1970-1971 Muffs retained the huge, wooly character of the earlier pedals but were less mid-scooped. The lower notes still had that gnarly breakup and slightly throaty low end, while lead tones bloomed easily and maintained a smooth, creamy feel.These pedals also show noticeable inconsistencies and can vary significantly from one another. Early versions are relatively close, with differences mainly in overall tonal balance. Some are slightly brighter in the tone section, while others are more open or bass-heavy. To my ears, V1 stands out, delivering a monstrous, throaty, wooly fuzz with strong breakup on the low notes and a clear, full, smooth lead tone.
V1: Monstrous fuzz with a throaty, wooly, gritty breakup on the lower notes and a full, blooming, smooth lead tone. The overall voice is balanced with just enough extra low end to give it a meaty fullness.
V2: Very close to V1, but with a little more top end and a touch more mids throughout the body of the tone.
V3: Similar to V2, but with considerably more high end, giving the upper notes an almost glassy quality.
V4: Overly bass-heavy with a tremendous amount of low end. Turning the tone control up to around two o'clock balances things out, producing a sound similar to V1, but with a smoother fuzz character.
V5: Plenty of gnarly, wooly, gritty fuzz with an open yet full tone on the lower strings. Lead notes have a broken-up, heavily saturated quality that almost borders on octave fuzz.
V6: Extremely close to V1, but with just a touch more top end throughout.
V7: A very rare version containing 2 µF capacitors where 1 µF parts are normally found. This is the only Big Muff I have encountered with these values, and their placement gives the pedal a huge, very open, gnarly tone that is also slightly brighter than the other versions.
V8: Unique resistor and capacitor values produce an incredible amount of fuzz. A massive flow of overblown, gnarly grit dominates the lower notes and adds a touch of hair to the smoother lead tones.