PCPics

(Sorry about the thread resurrection!) Only just discovered this thread - and what a resource, esp with regards the eras and the order everything was released. So I have a question which I’ve never seen explained: I have a GP12SMX with the 250wRMS/500wPeak amp (indicated by the silkscreened print on the back - not hand written) as part of the 1x15 combo - it has a cooling fan inside and no cooling fins on the back. I’ve had it for 20 years and apart from one service, has never done anything other than what I bought it for! I’ve just bought a spare head only (in the same textured vinyl case as the combo) - exactly the same spec, but with cooling fins and no fan. Identified as AH250 (hand written on the back). Is it the same amp?? I’m thinking the lack of fan noise might be for studio applications - but that’s a guess. Or is one the earlier model and the other slightly later? Any other differences (the front panels are identical), are either better/more desirable? Any insight would be appreciated.