Bob Seger said:
...Working on mysteries without any clues ..
jp said:
... Call me crazy, but I'm willing to bet Sister Tharpe is cranking through a Maestro--MA1-RVT? MA2-RVT? MA216-RVT?
Hi JP; not saying it isn't but I don't think it's an MA216-RVT - the only one of those I've seen was on eBay and it was covered in Epiphone grey tolex and is a variant of the GA19RVT. Floating in the ether is a schematic usually tagged GA19RVT that's internally labeled M-216RVT. It's the schematic for the GA19RVT 'Crest' Falcon - like yours and Guildzilla's - and probably for the 'Maestro' version I saw that was dressed up like an Epiphone. The tweed and 'Crest' versions of the GA19 take the larger, medium-sized Gibson cabinets.
In the pic below, that's default's GA1RT in the top two panels; shown for badge orientation and it's cab size and shape; 'low-rise' like an LP Jr / Skylark. Even though it carries a 'Maestro badge', it also has a 'GA' ID#. On the bottom, two of the later Maestro versions; both with 4 X 8" speakers ... though to be the descendents of the two-tone '50s GA 45 Maestro amps popular with harp players.
But I think you're on to something with the MA1-RVT but make it a
GA1RVT at Schematic Heaven This is the same circuit as the GA1RT including a single 6BM8 except a 6EU7 substituted for the 12AX7 and an added 7199. The GA1RT couldn't reverb its own signal; it was designed and sold as a remote 'echo' effects amp; like the Guild RC 20.
With the 7199, it could drive and recover its own reverb signal without having to have a larger cabinet. The GA1RT had a long-spring unit; that is, the cab was wide enough and there's plenty of space on the GA1RT chassis for another tube socket. The MA2RVT or
GA2RVT, assuming that the cabinet in the vid is as low as it looks, I don't think would fit; it's a two-channel, 5-tube preamp model ... which strikes me as alot of electronics for a shorty cab.
Anyway, while this is all speculation, I think you're probably right about the M or GA 1RVT ID but in a later, squared-off, low-rise cabinet with a Gibson badge; the fact is that default's GA1 with its 6BM8 puts out a terrific signal and it shouldn't surprise that Sister Rosetta mighta thought the same thing ... but she wanted reverb too! CJ