This is a vintage 1965 Magnatone “Estey” MP-1 electric guitar amplifier. With a good-looking black and silver sparkle cabinet and silver grillecloth, the MP-1 features; a duet of 7189 power tubes, a 12″ speaker, dynamic tremolo, (2) separate channels for both “instrument” and “mic”, and the original “kickstand” for tilt-back projection! Easily the best model from the MP-series, this special model is quite similar to Valco-made amps with similarly coveted configurations The pair of 7189 power tubes, often equated to, and interchanged with, EL84s, is a real treat when paired with a full-range 1×12″ speaker. Akin to an 18w Marshall, this amp produces incredibly rich overdrive while retaining some British-inspired clean headroom.
This amp is in very excellent all original cosmetic condition. Though it is not in perfect shape, it is well preserved and presents quite nicely. Like most amps with this covering, the back panel displays waviness. The original speaker was replaced years ago with a ’95 Eminence, and the power tubes were replaced at the same time. Those currently installed are Electro-Harmonix EL84s instead of 6973s, however, the preamp tubes are vintage and possibly original.
The MP-1 has two channels labeled: Instrument & Mic. The 1st, or Instrument channel, has two inputs (high & low gain). A 12AX7 is responsible for this channel’s volume, bass and treble controls, while the 12AU7 is used to drive a reverb transformer and springs. This channel and the Mic channel are summed by a 12AX7. Half a 12AX7 is used for a cathode driven incandescent bulb, in the Tremelo’s oscillator circuit. The 2nd or Mic channel has only volume and tone controls. The phase inverter uses a 12AU7 to drive two 7189A power tubes and the output transformer into a 12 in. 8ohm speaker.
This amp includes the original single-function reverb/tremolo footswitch. It also includes a non-original formfit black vinyl cover.