If you know, you know. This is an absolute beast of an amplifier, with a sound reminiscent of the old Sunn amps. It is equally suitable for bass or guitar. Rated at 375 watts at 2 ohms.It can be used for guitar, bass, keyboards, synths and drum machines. Condition is good but will pots will need to be cleaned. Famously used by Rush, The Isley Brothers, and Mahavishnu Orchestra, among others!