Biasing Instructions - Rivera Knucklehead Reverb KR 55T Owner's Manual

Biasing Instructions:

Place amplifier on a stable surface.
Remove rear Tube Grille on cabinet.
Disconnect Reverb Cables plugged into the Jack on the chassis surface.
Remove the 8 chassis mounting bolts from the bottom side of the cabinet.
Place the chassis open side up on the workbench. Be careful not to damage the power
tubes.
Measure your AC Mains voltage. If you have a Variac, adjust the Mains voltage for
whatever the amp is labeled for, i.e., 100VAC, 115VAC, 230VAC, etc.
Observe the location of the Bias adjustment pot on the motherboard. It is located near
V5.
Observe the two wires connected between the output tube circuit board and the speaker
jack board. These wires carry the output tube cathode current.
Connect your current meter across the pads of the speaker jack board where these two
wires are soldered to.
Bias Adjustment Pot
Test Points
Black and White
Wires
Knucklehead Reverb 1.0 p 39