67’ Marshall Model 1987T (JTM 50) “Black Flag” [GZ34]
-4x EL34

-4x 12AX7

-1x GZ34 Rectifier

-JTM 50 “Black Flag” Circuit

-Original Drake Transformers


*Amp thoroughly checked on and “gone over” by Greg Germino

**Below is Greg’s dossier for the amp. It documents EVERYTHING

1967 Marshall Tremolo 50w Black Flag circuit.

Window style serial no T/ 10163

All pots date 7-7 Assembly of this amps date to post middle of 1967.

Apart from two changed switches this amp is original with all original transformers, coupling caps, resistors, pots, indicator lamp, etc.

Was at one time converted to ss rectifier, now back to GZ-34.

Panels are clean with only minor discoloration on front plexi panel at switches. This amp exhibits all build characteristics of what is referred to as “Black Flag” period, early 1967 through late in that same year.

There were both reverse typeset JTM panels and JMP panels used in production at this time. Doubtful that there were any JTM Tremolo front panels during production. The circuit shows all the common build aspects for BF production…non perforated board material. The majority of resistors are the red Phier brand associated with JTM-45 and JTM-50 era. There are 3 Iskra brand resistors in the V2 board are which were intermixed during this time period. The Phillips/mullard mustard caps are dated B6N of the .022uf and D6N of the.1uf. This is very typical of early through post mid 1967 production. This amp uses the AEI brand octal sockets typical with early mid 1967 production. Filter capacitors have been replaced with correct values as well as bias supply capacitors and cathode bypass cap in pre-amp. A bias trim pot has been added and bias resistors at each output tube socket. All service work was performed by Greg Germino of Germino Amplification.

Pictures show all interior and exterior views of chassis and circuit as well as original Drake 1202-118 PT, 784-139 OT and 352-114 choke.


For audio/video inquiry get at me at “thegearangle” at proton mail…. Will put amp through it’s paces!

Amp ship’s Fast & Secure !

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Listed3 days ago
ConditionVery Good (Used)
Very Good items may show a few slight marks or scratches but are fully functional and in overall great shape.Learn more
Brand
Model
  • JTM50 "Black Flag" 1987 Lead 2-Channel 50-Watt Guitar Amp Head
Finish
  • Black Levant
Categories
Year
  • 1967
Made In
  • United Kingdom
Power Tube Type
  • EL34
Number of Channels
  • 2 Channels
Electronics
  • Tube
Direct Output
  • No Direct Output
Number of Inputs
  • 4 Inputs
Impedance
  • 16 ohms
  • 8 ohms
  • 4 ohms
Reverb
  • None
Color Family
  • Black
Output Power (Watts)
  • 50

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The Gear Angle

Cincinnati, OH, United States
Joined Reverb:2019

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