Just picked this up. I don't know the year, or how much is stock, it seems to have some aftermarket and homegrown components. The speaker is a huge upgrade, a rare and sought after Pyle Driver! All I have on hand is an EVM15L, I may put that in and see how I like it. Can't afford to buy a replacement speaker.
Functionally, I have a concern, maybe somebody has experience with these amps and can help. Is channel 1 generally quieter? It reacts like it has an input pad, have to get the volume close to half to be as loud as channel 2 is around one quarter. Both channels also have no volume until they are turned up a bit, channel 2 becomes audible much earlier than 1. Is this normal? I can take it back within a week and get it repaired free, but if it's just the way the amp's volume controls react there's nothing to repair. The loose input jacks I can take care of myself. I'll probably want a 3 prong power cord, but that won't be free.
The "B12" on the circuit boards on the pots makes me wonder if the head began life as a B12; the chassis looks aftermarket to me, newer than the rest and unmarked in the back. But then again, I'm pretty cluless. It sounds good though, even with the current speaker. Had to trade in my beloved Genz Benz GBE750 to get it, but the Genz didn't have power tubes so it's not like it has a soul, or feelings or anything.
detailed pics (let me know if you can't view these - never used photobucket before):
http://s1177.photobucket.com/albums/x355/Wim_M/Ampeg/