Troubleshooting guide

Knucklehead Reverb 1.0 p 33
Note: On SEMKO-CE 230/250-volt models, there are two additional T
1.6A (250-volt Slo-Blo type, 5mm x 20mm) fuses and one T 10A (100
Watt Version) or one T 8A (55 Version) (250-volt Slo-Blo type, 5mm x
20mm) fuse located internally. These protect the amp's output tube
filaments and should only be replaced by qualified service personnel. y
When this fuse opens, the output tubes will not light up, and this is
usually due to a Mains Voltage surge, or a shorted output tube.
There's unwanted distortion
Check the speaker(s).
Check the cables.
Check the signal level at other devices in the signal path.
One or more tubes may be bad (refer to the tube information in this manual, or take
your amp to qualified service personnel).
Tube Care & Replacement
Like a sports car, there's a certain amount of wear and tear to be expected in a high-
performance tube amp. Over time, especially with hard use, tubes may need
replacement. That's why it's a good idea to make note of when you purchased your
amp and whenever you replace tubes. It's no accident that your amp has two common
types of tubes: They're great-sounding and reliable, and it's easy to find replacements.
Here's a tube chart to show you which tubes go where.
Location Type
V1 12AX7A, 12AX7WA or 12AX7WB
V2 12AX7A, 12AX7WA or 12AX7WB
V3 12AX7A, 12AX7LP or 12AX7EH
V4 12AX7A, 12AX7WA or 12AX7WB
V5 12AX7A, 12AX7LP or 12AX7EH
V6 EL-34
V7 EL-34
V8 EL-34
V9 EL-34
Note: In 55 Versions, V8 and V9 do not exist.