1987 .22 Caliber Tubes

Siebecker · May 1, 2016

I have a 1987 .22 Caliber with EQ. There are 5 12AX7 tubes. Can anyone describe for me the function of each 12AX7 tube and it's socket location? There is no diagram on the amp and I can't find anything on the internets. Any help would be appreciated. Thanks.

Bob in Chicago.

Stratcat · May 13, 2016

The manual is available on line and describes tube location as follows:

Viewing from the rear of the amp:

V5 - V4 - V3 - V2 - V1 (where V1 is furthest to the right)

A description of their function is not as clear but implies:
Lead V1
Rhythm V2, v3
Reverb V4
V5 - ???

Hope this helps

Don · May 13, 2016

Here's a little more detail. These are to the best of my knowledge, looking at the schematic and manual.

V1A and B are the 1st gain stage in the lead mode
V2A is the 1st gain stage for the rhythm mode and the 2nd gain stage for the lead mode
V2B is the tone control return
V3A is the effects return
V3B is a gain stage for both modes
V4A is the reverb return
V4B is the reverb driver
V5 is the phase inverter

1987 .22 Caliber Tubes

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1987 .22 Caliber Tubes

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