Someone mentioned this model of GK amp and I looked to see what was for sale and found one on Ebay listed as "not working or for parts". The seller was a charity and they said it powered up but they had no way to test it. I threw a bid at it and won it for $66...$88 total with shipping. It arrived today. The pots were dirty...some Deoxit 5 took care of that, some of the fins on the heatsink were bent...careful use of long nose pliers took care of that and it works just fine and sounds so good. I have some friends who still gig with the GK 400RB head and for good reason. It is reasonably powerful and sounds just great. Yeah, it is a little heavy and it won't fit in a gig bag but what an amp for less than $100. This one will take up residence at our rehearsal space and will power a 4 ohm SWR Goliath, jr 210 that I have that is not being used.