Rear Panel Features (from left to right)
A.C. Mains - Plug IEC AC Power cable from 120VAC wall socket in here.
Fuse - Use a 2.5 amp fuse. Consult qualified technician in event of failure.
Bias - To bias amp: with amp off, set voltmeter to DC millivolts. Insert flat-head
screwdriver into bias adjustment slot and rotate fully clockwise. Insert negative
lead of voltmeter into "Ground" jack on amp. Insert positive lead of voltmeter into
V1 jack on amp. Turn on amp. Adjust bias control until meter reads 32-42mV
(37mv optimal) for 6L6 power tubes, or 27-37mV (32mV optimal) for EL34 power
tubes. Plug positive lead into V2, V3, and V4 jacks to check matching.
Mains - Main power switch for amp. Turn this switch on first when powering up
amp and off last when powering it down.
Standby - Standby switch. Turn this switch on 1 minute after Mains when
powering up amp. Turn it off 10 seconds before Mains when powering amp down.
Speaker Output - Always ensure that a speaker or load is connected to one of
these jacks whenever the amp is powered up. The main and extension jacks are
wired in parallel: (main * ext.) / (main + ext.) = total impedance load.
Impedance Switch - Set this switch to match the total speaker load plugged into
the Main and Extension jacks. EX: With a single 8 ohm cab plugged into Main, set
this to "8". With one 8 ohm cab plugged into main and one 8 ohm cab plugged into
extension, set this to "4": (8*8) / (8+8) = 4.
Effects Loop - This is a series, buffered, post overdrive, pre-reverb signal access
connection. The "Send Level" control is always active so you'll need to adjust this
to an appropriate level to avoid overloading the built in reverb. The optimal setting
will vary based on how high you have the amps volume and tone controls set. "5"
is a good starting point, though. If the amp is producing a harsh, un-natural
distortion, try turning the send down.
Control Switches - The "Reverb," "Drive," and "Boost" switches turn the reverb,
overdrive, or preamp boost features on or off. These should be in the "off" position
if the foot-switch is being used. DANGER:
HIGH VOLTAGE!
Refer servicing
to qualified
technician.