2. Check the cables.
3. Check the signal level at other devices in the signal path.
4. 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
V2 12AX7A
V3 12AX7A
V4 12AX7A
V5 12AX7A
V6 6L6
V7 6L6
Here's a brief description of what each tube does:
V1
Input buffer and tone control driver for Channel 2, and also the first Preamp stage of
Channel 1.
V2
Tone control follower for Channel 2 and an additional gain stage for Channel 1.
V3
Third gain stage for Channel 2 and for Channel 1
V4
Reverb follower gain stage, and mixer for both channels
V5
Phase inverter driver tube for the power amp section
