Power Output Switch; Ht Fuse - Rivera Knucklehead Reverb KR 55T Owner's Manual

Power Output switch

Between the use of the High Power/Low Power positions in combination with the use of
the Vintage-Modern Switch, 4 different output voltages can be accessed:
100 Watt Versions
Power Output
High 100W 50W
Low 25W 12W
55 Watt Versions
Power Output
High 55W 30W
Low 12W 8W
The actual high voltages as well as the bias voltage is changed when switching
between High and Low Power setting. The amp may be on, but does not play or feed
signal at the moment that you switch. A thumping noise can be heard through the
speakers and this is normal.

HT Fuse

The power amplifier circuit has its own fuse for protecting the output section from short
circuits and transient current peaks that exceed the normal current draw. These
conditions are usually caused by a bad tube. When a short circuit or transient peak
causes the fuse to blow, the output tubes should be checked and replaced, if
necessary.
For 100VAC and 115VAC 55 versions, the HT Fuse is:
1/2 Amp, 250 Volt Slo-Blo type (3AG, or MDL).
For the 100 versions, the HT Fuse is
1 Amp, 250 Volt Slo-Blo type (3AG, or MDL).
For 230/250 VAC 55 versions, the HT Fuse is:
T 1A (time-delay, 5mm x 20mm size).
For 100 Versions, the HT Fuse is:
T 500 Ma (time-delay, 5mm x 20mm size).
Note: Repeated blowing of the HT fuse is a clear indicator of a defective
output tube. Always use the correct fuse value when replacing the HT
Fuse.
Modern Vintage
Modern Vintage
Knucklehead Reverb 1.0 p 18