Ed Green bought this Magnatone Custom M-15A new in 1965-66. It has 2 seperate input channels, (each with high or low gain), plus a Stereo input. 3 12AX7/7025 preamp tubes for the treble, bass, loudness and contour controls. This amp uses 3 of the 12DW7/7247 split mu tubes. The hi mu sides are used for phase inversion and a low freg. oscillator. The medium mu sides are used in the 1st vibrato shift and the 2 shift recoveries. A 12AU7 drives the 2nd vibrato shift. Another 12AU7 to amplify the low freq. oscillator. The Reverb input comes from the secondary side of one output transformer# T2 20-0155. Another 12AX7/7025 tube recovers the reverb. This model M15-A also has an "Echo" control that I am told sounds like it gates the reverb using an LDR circuit on the reverb output. This M15A reverb circuit is different from the M-15 and the "Dual Imperial" models, which use a tube driven reverb circuits. The M15 has a tube recovery, and the "Dual Imperial" uses a transistor returns. Four 7189A power tubes into stereo output transformers, into 2 12", 16ohm, Jensen model C12P speakers (one labeled: 220536, 25-1024, C12P 8274, and the other labeled: 220545, 25-1024, C12P 8274).
Email Ed if you know where he can get the speakers reconed. He lives in Calgary, Alberta.

Approx. 75 Watts
Serial Number: 3255
Owner: Ed Green, Not For Sale.
Photos: ©1997 Ed Green. Used by permission.