So this is what I picked up on a recent trip down to Oregon from Vancouver:
The first sound you hear upon powering up the 500 is the whir of its two cooling fans.
I had a choice between the ADA and a DOD preamp, but the ADA was already in place, and I didn't know anything about the DOD, so I just accepted the ADA. I'm planning on replacing it with a JMP-1 eventually. I think the ADA needs new tubes, I get some crackling when using certain distortion presets.
I think this rig will have to stay in the basement, because it's too loud for upstairs (where amps can easily be heard outside the house) and down there I'll have a lot more room to back away from myself it than I do upstairs.
I'm a bit concerned about playing it through my Avatar 2x12 with a g12h30 and V30. Since this amp's 200 watt / channel, that's a recipe for blowing a speaker, right?
The original Craigslist posting for this sale is this:
http://salem.craigslist.org/msg/1506148420.html
Also, the guy I bought it from claims that for some reason the tech who last retubed it had to dent the chassis to fit in the 6550 tubes. I don't understand why they'd require that to fit, but here's a pic where you can see the mounds made in the chassis to accomodate the tubes:
I still haven't yet given 'er any in-depth use, so my opinion and understanding of the device is very not yet matured. Still, I am very happy to own it!