1961 Maestro (Gibson) GA-45RV 45w 4x8" Tube Combo Amp


This is a cool amp. This variant of the GA-45, the RV with its 4x8" layout, was only made in '60 and '61. I looked-up the transformer codes and they indicate '61 manufacture. Gibson made these under the Maestro brand and intended them as accordion amps. Apparently, harmonica players are into them as well! I mean, 8" speakers do work well for harps with their clear, midsy chop. To me it's almost "Chicago-y sounding" in that it's a little bit Bassman-like and a little bit Premier-like and a little bit Harmony-like. It's got a solid low end when you crank the bass and the treble doesn't get brutal like an old Fender but it's bright, chipper, and responsive when you turn it up.

A friend of mine owns the amp and brought it here for sale. He's had it for a long time and, considering his absurd herd of vintage amps, I can understand why he might want to downsize a bit. When he bought it to begin-with, its original speaker complement had been reduced from 4x8" to 1x15" instead. He had an amp tech fit a new "Baltic birch ply" baffle (and, presumably, a new grill cloth) and a set of repro Jensen 8" speakers. At the same time it looks like a number of the old electrolytic capacitors were replaced with Spragues and whatnot -- good-quality stuff. The job was tidy on the boards and silicone was used to keep the "big boys" secure.

It arrived here working well save that it needed the 2-prong cord and "death cap" replaced with a 3-prong cord. The reverb was also not working.

I swapped the 3-prong cable in, no problem, but it took me a while to suss-out the reverb situation. I resoldered the pin connections for the RCA jacks going into the tank and then chased-down any leads running to and from them. Eventually I found a bad connection at the old RCA cable running into the input section from a tab on a transformer. I swapped the whole RCA cable out with a spare for good measure and, hey presto! -- we're off and running. I also resoldered the footswitch to its mounts on the output tabs of the tank and replaced any replacement wiring runs (there were two or three) that looked a little messy.

It's now running nicely and sounds excellent.

The control panel has a lot of plating pitting and much of the labeling is worn-off so I did mark what each input jack does. The first channel was intended as a "mic" channel when new and it has a second, lower-gain input. This first channel does not work with the reverb. The second channel is intended as an "instrument" channel and both it and its lower-gain input work with the reverb.

So, let's recap...

What's been changed? The original baffle, grill cloth, and speakers were missing and replaced with a new baffle, grill cloth, and 4x8" repro Jensen speakers before my time. It has a mix of newer and older tubes but all are good. The amp jewel is purple so I'm assuming it's not original. A number of capacitors have been replaced and/or upgraded inside, but most of the original equipment is in there. The cord has been replaced with a 3-prong, grounded one. One of the RCA cables running to the reverb tank is not original.

What is the condition? It's "ready to go" with the caveat that the tube sockets are all a little wiggly and should be retensioned or replaced if this is to be an amp traveling a lot on the road. That's the only thing I would change if I were thinking of using it a lot at gigs. They're good for light use or studio use, however, but I wouldn't trust them if this were getting tossed around in a touring van. Also, it clearly has a number of modifications and a ton of wear and tear to the cream-colored tolex. I mean -- someone smoke much?!
























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