These are great sounding amps and real sleepers on the vintage market in my opinion. After decades of being ignored, non-Fender amps finally started appreciating around a decade ago and while a Gibson, Magnatone, Valco, etc., may never get the money of a blackface Fender from the same era, they’re so undervalued that most vintage experts know that most have definite growth potential. More importantly, amps like this sound great, and can be had for a price that doesn’t hurt. The Custom M15 is one of the cooler amps of this era, built when companies weren’t afraid to try anything, like this “Royalite” thermoplastic case. Unlike Fender, which has never made a true vibrato (pitch shifting) amp, Magnatone built amps with real vibrato and the effect is stunning. Additionally, the M15, is a true stereo amplifier, with dual output transformers and twin 8″ Alnico speakers, four 7189As power tubes (two matched sets), and two phase inverter 12AU7A tubes. It is equipped with stereo output channels (not just two input channels). Each input channel has its own pre-amp, and both of these signals are equally mixed together on both output sections. There is Stereo vibrato, but it only applies to the signal from Channel No.1 input. That signal is send to two different vibrato units, which each go to one of the two output sections. Confused? The Stereo vibrato switch, in mono mode makes the two vibrato units modulate at the same frequency, and in “out of phase” frequencies in stereo mode. If vibrato was simply ON or OFF, the two vibratos, in stereo mode, might cancel each other out, however herein lies the magic. The Magnatone vibrato is the varistor. These magic varistors rise and fall at a much slow rate, so the rise and falls of the two output of phase vibratos never match up perfectly enough to cause complete cancellation. This unique vibrato circuit was used by Magnatone, who called it “Stereo F.M. Vibrato.” Controls are (L to R): two sets inputs with a stereo input jack between them, each input with volume, treble, and bass controls, a contour switch and a pair of input jacks. Next is the four control vibrato section and foot switch jack, followed by a single reverb control and foot switch jack. At the far right is the power switch and output speaker switch with left and right speaker output jacks. Power output is listed as 2X38 watts “peak”, which probably equates to around 12-15 watts X2. This amp uses a bunch of tubes, around 13 total including four 7189A power, three 12AX7 preamp, two 6GW8 reverb, three 12AU7 and a 12DW7 vibrato, two 12AU7 phase inverters. There were several design changes that took place on these amps between ’63 and ’65. I’ve done my best to accurately reflect the design aspects of this amp but apologize in advance if there are any inaccuracies. Most of the information above came from a fantastic vintage Magnatone site, MagnatoneAmps.com. This is a very good sounding amp with some of the coolest effects I’ve heard on an old tube amp. It works well, although could probably use some minor tweaking/cleaning. It was last gone over by Jeff Bober, who owned Budda at the time, back in ’95 (see the “JB” in the pic of the back). It’s a heavy amp and I’d estimate shipping to be around $75. I will guarantee that you’ll be the only kid in the band with this baby and probably have a blast playing it. I think it’s a steal at $650.