Specifications

1
3
4
2
1 2 3 4 5 6 7 8
5
6
7
8
6350
12AT7
INPUT
RCA
OUTPUT
B+ MAINS
FUSES
IEC MAINS
IN
1 2 3 4 GND 5 6 7 8
BIAS READOUT POINTS
Amplifier Overhead View
Bias Adjustment Points:
Tube Location
TRIODE
SWITCH
TETRODE
TRIODE / TETRODE SWITCH:
With this switch, the amplifier may be set for TRIODE or TETRODE operation. When the switch is in the forward
position, the amplifier is in TETRODE mode and the green led is not illuminated. When the switch is in the rear position, the
amplifier is in TRIODE mode and the green led is illuminated. THE AMPLIFIER MUST BE TURNED OFF BEFORE
THROWING THIS SWITCH!!!!!
OUTPUT TUBES: 8 X 5881
The 5881 is a Russian military up-rated 6L6 type. This has been proven to be the rugged and reliable of the 6L6 types
and we strongly emphasize that only the 5881 should be used in this amplifier. The MANLEY 175 WATT MONOBLOCK has
been thouroughly optimised around this tube.
DRIVER TUBE: 6350
The 6350 is an American military uprated version of the 12BH7A but WITH ONE IMPORTANT DIFFERENCE!!!
The 6350 has a differnt pinout to the 12BH7A. Thus ONLY the 6350 can be used in this circuit. THERE IS NO OTHER
SUBSTITUTE!
INPUT TUBE: 12AT7WA
The 12AT7WA has several equivalent numbers, (12AT7, 12AT7A, 6201, ECC81, etc.) Any of these types may be
used. We have selected this 12AT7WA very carefully for noise, microphonics, and constancy. Replacement tubes of premium
quality are always available from MANLEY LABORATORIES.