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Lordathestrings
Gear Guru
Joined: 01/18/01
Posts: 6,242
Lordathestrings
Gear Guru
Joined: 01/18/01
Posts: 6,242
02/13/2004 6:33 pm
'Can't be sure without a schematic. Each tube has two sections in it, so each one could be a separate two-stage channel. If each channel has it's own EQ or Tone controls, this is probably what's happening.

The whole idea here is try something different. All three channels are using 12AX7's, so you should swap out one of them to see which channel that tube controls, and to see if you like the new tube better than the original. You might also want to try a 12DW7. This has one high-gain (100) section like a 12AX7, and one medium-gain stage like a 12AT7.

Look at the base of a tube, and you will see that there is a gap where it looks like a pin is missing. This feature allows you to be sure to get the right pin in the right part of the socket. Shut down the amp, and use a clean, dry cloth to grip the tube you want to change. [u]Gently[/u] rock it back and forth a little bit as you pull it out. Note which way the gap in the pins is facing, so it will be easier to line up the new tube with the socket. Install the new tube, again rocking it gently as you push it all the way into the socket. Now, fire up the amp and see if you like it.

[Edited by Lordathestrings on 02-13-2004 at 12:35 PM]
Lordathestrings
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