The HJ Custom 50

The Harry Joyce Custom 50

The Harry Joyce Custom 50

Harry Joyce 50/100 watt

The Harry Joyce 50/100 watt amplifiers are an A-B class amplifier. These are all point to point, hand built by George Scholz right here in the U.S. 

It provides 4 inputs:
Normal Hi/Low

Brilliant Hi/Low

This amplifier is a master volume design which includes:

Gain controls for Normal or Brilliant inputs, Tone controls for Bass, Treble, Mids and Presence. The pre-amp stage uses 4 ECC83 (12AX7) Pre-amp tubes for inputs, tone, voltage amp, and driver. The output stage (output transformer) is designed for EL34 (6CA7) power tubes.

On the back side, voltage and ohm selector, 2 speaker outputs (in parallel) and an unbalanced slave output (signal is tapped directly off the output transformer). Hum balance, send and return (effect loop), as well as, fuse holders for power, high voltage supply and I.E.C. Power Entry Module.

Upgrades on newer units include:

-Stainless steel chassis (9 lbs)

-Enlarged filtering in power and bias supply

-All ceramic tube sockets

-Improve shielding & layout

-2 watt resistor value

-Hum balance

Specs for 50 & 100 Watt amps:

Input resistance-High: 1meg ohm
Input resistance-Low: 136K ohm

Inputs can be linked from channel to channel

Input sensitivity 2.5 M.v.@ 500Hz

Tone controls:

Bass + minus -20db

Treble -6 to 30db with presence

Middle +10db

50 Watt Amplifier / 100Watt Amplifier

Output Power RMS: 50 Watts / 100Watts

Total Peak Power: 50 watt head 125 Watts, 100 watt head 250Watts

Input Volt Selector: 100V, 115V, 230V , 240V (not connected)

Output Ohm Selector:50 watt 8,16 ohms,100 watt 4,8,16 ohms

Effect Loop: 50/100 -Send through master output, return input 1 meg ohm

Slave Output: 50/100- Level Dependant

Preamp Tube: 50/100- 4x ECC83 (12AX7)

Power Tube: 50 watt- 2x EL34 (6CA7) ,100 watt- 4xEL34 (6CA7)

Rectification: 50 watt- 3x 1N 5408, 100 watt- 5x 1N 5408

Fuse Power: 50 watt -3A @ 250V slow acting , 100 watt – 4A @ 250V slow acting

Fuse High Voltage: 50 watt 500mA slow acting,100 watt 1A slow acting

Cabinet Dimension Approx: 50/100 -11″ H x 22.5 ” W x 10.5″ D

Weight: Approx. 50 watt 48 lbs.- 100 watt 51 lbs.

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