JTM 45 / JMP 50

Circuit: original British circuit from '62 with improvements
Rectifier: GZ 34 / 5AR4
Power Amp: 2x 6L6 or 2x KT 66 or 2x EL34, 45 W
Bias Circuit: fixed type, adjustable on bias pot
Driver/PI-Stage: 12AX7
2nd Gain Stage: 12AX7
1st Gain Stage: 12AX7 (12AY7 optional)
Controls: Presence, Bass, Middle, Treble, High Treble Vol., Normal Vol.
Inputs: High Treble Volume Hi 1, Lo 2
Normal Volume Hi 1, Lo 2
Output: two speaker outputs on jack
Output Z: switchable 4/8/16 ohms
Features: aluminium chassis, hand wired, point to point on turret board


  • speaker simulation on balanced XLR output
  • tube rectifier / diode rectifier switch
  • adjustable feedback
  • Line Out
  • Wild switch
  • fixed bias / cathode bias switch
  • Plexi Boost switch
  • Fat / Tight switch for both input stages
  • Bright switch for both input stages
  • 12" speakers
  • available as Top or 2x12" Combo (64' or 65' Version)
  • Covering and Grill
  • Colour / Shape of Control knobs
  • Custom voicing and tone shaping on request

Builders Statement:

I personally own and played originals for over 10 years, so I know them all very well.
This amp is a bit more fore the rocker or blues rocker because of its higher gain structure of the input stage.
The amp let you produce all the classic British sounds of the mid sixties, you got instant Cream, Hendrix, Free
and Who sounds with the corresponding guitars.
Amp likes all pedals while still offering a good dynamic range.
I recommend Alnico speakers, but amp sounds good with ceramic magnets, too. It's a matter of taste and money
which speakers you will use.
EL34 version
6L6 version