Marshall JMP Super Bass (1992) Head – 1974 – Impeccable Condition

We are offering this incredible amplifier from our private collection. Opportunities to find a true original “Plexi” in such immaculate condition are extremely rare — it’s like Marty McFly brought it straight from 1974 in the DeLorean.

This is a 100W head featuring the classic configuration of 4 × EL34 power tubes and 3 × 12AX7 preamp tubes. The circuit is essentially the same as a Super Lead 1959, but with a much smaller bright cap, which results in subtle yet important tonal differences.

Originally designed as a bass amplifier, the Super Bass quickly became a favorite among guitarists looking for a cooler, less aggressive, and creamier tone. Famous users include Jimi Hendrix, Paul Kossoff, Eric Clapton, Pete Townshend, Angus and Malcolm Young, Eddie Van Halen, Gary Moore, Duane Allman, and many others. Of course, it was also widely used by bass players, as seen in photos and videos of Noel Redding with the Jimi Hendrix Experience.

So what’s the difference between a Super Bass and a Super Lead? Only about three component values in the circuit — they are essentially the same amplifier. This is why so many Super Bass heads were converted to Super Lead specs during the 1970s.

Tonally, the Super Bass delivers slightly more low end and midrange, sounds far more musical at lower volumes, and — crucially — is much easier and better to use with pedals. It also offers more clean headroom, making it an exceptional platform for big, transparent clean tones. When pushed into overdrive, it feels softer, spongier, and creamier than a 1959 Super Lead, with a fuller sound and less aggressive bite.

This amplifier has seen no stage or studio use. It has been kept strictly as a collector’s piece and only received routine maintenance. The circuit is 100% original, with the only replacements being the aged electrolytic capacitors, as expected for reliability. It has been fully serviced and fitted with brand new tubes throughout by a technician specialized in vintage Marshall amplifiers.

There is a small mark on the tolex, which comes from the original hand-assembly process used at the factory. It is not a dent or abrasion, as this amplifier has never been used live.

The amplifier includes the original power cable with Bakelite Bulgin connector, professionally adapted to a European mains plug.