Craig sent us this photo of his Model MP-3. It was sitting in his neighbor's garage for years. The neighbor almost gave it to Goodwill Industries, but on second thought gave it to Craig, the loud musician next door. Craig says he loves it, but it could be louder in the low end.

The model MP-3 has two channels (each with high & low gain) preamp'd by a 12AX7. Each channel has a Volume, Treble, Bass and Reverb control. Each channel uses the other half of a 12AX7 in the 2nd gain stage but the tremolo channel uses the medium-mu side of a split-mu 12DW7 as an extra gain stage. The other high-mu side is used to develope the low frequency oscillator for the tremolo. Note: Do Not contact the grid (pin 2) of this 12DW7. Current surge may burn out the GE1869D lamp in the oscillator circuit. A 12AU7 drives a special transformer for the reverb tank. Followed by another 12AX7 for the reverb tank amplifier stage. The reverb section has a depth & tone control. Another 12DW7 split-mu is used for the mixer/inverter stage. The medium-mu side for summing and the high-mu side for the phase inverter. Two 6CA7/EL34 pentodes deliver the power to output transfomer and then two 12-inch 16 ohm speakers. A control labeled normal & record is used to bypass the the phase inverter, power tubes and output transformer resulting in a low level signal at the external speaker jack. There are also footswitch jacks for the tremolo and reverb. There is a knob labeled dimmer that controls some neon lights for the control panel.

Approx. 35 Watts
Serial Number: Not available
Owner: Craig Downing, Not For Sale.
Photo: ©1998 Craig Downing. Used by permission.

For more Information contact: Magnatone-Valco discussion group Vibroworld has Magnatone Parts

Bill sent this photo and has some more details. Transformers are indicated: Power: 20-0024, Custom Coil Co. Output: 20-0121A CT 213A. The amp had Jensen 1966 C12PS speakers but Bill put in Mojo 12" ceramic speakers and say they sound great. When he got the amp serviced, new tubes, bias adjust, caps, etc. It sounded great, good tremolo and reverb but a little too hard to break up and not quite loud enough for a 40 watt amp. Bill rebiased the first gain stage and played a little with the circuit to a more traditional Fender style first gain stage and says it really growls now. He says: "I love this amp - much lighter than my SF Twin Reverb or AC30 & a great jazzy, full bodied vintage tone. Only wish it had the real vibrato!" Will is also interested in buying a 213A or M10A.

Approx. 35 Watts
Serial Number: Not available
Owner: William Boyd, Not For Sale.
Photo: ©1998 William Boyd. Used by permission.

For Sale, MP-3. Contact: Hal Gulliksen

Approx. 35 Watts
Serial Number: Not available
Owner: Hal Gulliksen, For Sale contact:haltone@aol.com
Photo: ©2000 Hal Gulliksen. Used by permission.