Gibson Maestro Maestro GA-45T: Preamp tubes: two 5879; 6SQ7 tremolo; 12AX7 PI Output tubes: two 6V6GT, cathode-bias Rectifier: 5Y3 Controls: Volume on each channel, shared Bad and Treble, tremolo Depth and Frequency Speakers: four 8″ Jensen DP-Alnico-5 Concert Speakers Output: 15 watts RMS
The amp has the original foot-switch and a 3 prong cord was installed when I had it serviced at The Amp Lab in Campbell, Ca. A year or two ago. Not sure what all was repaired but channel 2 was intermittent. The amp sounds great and is in excellent working order with slight cosmetic defects to tolex as shown in photos but otherwise really good condition.
The GA-45T has a paraphase PI like tweed Fenders from earlier in the ’50s. The Maestro also carries a choke, but more significantly, those 5879 preamp tubes are simply nothing like the 12AY7 or 12AX7 found in Fenders. A little closer to the more familiar EF86 pentode than anything else, they are less microphonic than that occasionally troublesome tube of the vintage Vox AC15, and just fat, wide, warm, and greasy-sounding all at once. In short, they’re the bedrock of a tone all its own. As well as having more gain than the more common 12A-7 dual-triodes, they also handle input voltage more elegantly, which means they don’t fizz up into hairy dirtballs of tone, and instead pass a thick, rich frappe of a soundstage along to further stages of the amp.
Aside from the differences in the speakers, the two-knob EQ seems to rein in the GA-45Ts gain just a little from that of the GA-40T, but that’s not entirely a bad thing. Those 5879s are fat-sounding tubes, and ramp up the gain in a big way in the first place, so it survives the two-pot journey well. If anything, you get a jot more twang than in the GA-40T, although all bets are off once you crank up either one of them past half way.
The other disparity between the Gibson and the Maestro is, of course, the speaker configuration. The GA-45T sounds good with guitar with its stock 4×8″ rig, but plug it into a 1×12″ extension cab with any reputable driver and it really comes to life. A Jensen P12Q, Celestion G12H-30, or Celestion Alnico Gold produces great (if varied) results, and the amp reveals firmer lows, more aggressive and blooming mids, and much more giggable volume levels. The 22″ (wide) x 20″ (high) cab even allows for a 15″ speaker, if you want to cut such a baffle. Being spec’d for accordion, the four 8″ speakers also work a treat for harp, of course, and the fact that blower extraordinaire Little Walter wailed on a Maestro GA-45T lends kudos to the model.
Above is from a write up by Dave Hunter in Vintage Guitar Magazine. In my experience its spot on. Most of the clips online don’t do this amp justice. Its not very loud but the tone is thick, really nice. I am having a hard time letting this go, I told myself I wouldn’t let the GA6 and the Maestro go ever, a mistake I made awhile back with a mint 1966 Deluxe Reverb I sold which I still regret to this day. But alas, they are both listed here on Reverb.
