Invader 60 valve amplifier

made in the late sixties/early seventies this amplifier is a valve amp with three channels - two of which are high gain for guitars and each with volume controls, and a third which is low gain for a keyboard or similar also with volume control.
There are bass and treble controls and an on/off switch. The condition is very good and it has been fully checked and serviced professionally and is fully working. It has similarities to the early Marshall amps and may well have been designed by the known ''HH Electronics''.