Drew's Geezer Amps

This is a 1967 Marshall JTM/JMP 50 Plexi. A 50W tube rectified EL34 model transitional between the tube rectified Black Flag JTM 50 and the solid state rectified 1987 models.

Cabinet rear. Cabinet probably has been recovered but using vintage green hue Marshall tolex some years ago.

Requires a Bulgin style power cord.

Back Panel removed.

The JTM 50's were the first to use the 784-139 output transformer designed for EL34 tubes. The power transformer has been changed to a Mercury Magnetics copy of the original, bringing the cost of this amp down to my price range. The paper date stamp sticker has been lost.

V1 is common cathode design. The grey Radio Spares capacitors are likely original to this amp. Innards are in good shape, I only added a bias trim pot.

Close up of the power section.

Another view of the board. All of the electrolytic capacitors on the board have been replaced.

Another power section view.

The 1967 JTM/JMP 50 atop a 1970 model 1987 and a 1960AX speaker cabinet loaded with Weber Silverbell and 1230-55Hz speakers.