[Harp-L] Super Reverb (Perry White)

["Don Z" <dzeller@xxxxxxxxxxx>]

Perry,
Some preamp tube substitution  to decrease feedback and allow you to push the power tubes harder than you could otherwise would be easy, safe, and remarkably effective in turning the Super Reverb (or Deluxe Reverb or Vibrolux Reverb or Showman Reverb or Pro Reverb) into a harp screamer.  Always power off to swap tubes.
If you look at the amp from the rear, there are 6 "preamp"tubes lined up, usually 7025s, 12AX7s and  12AT7s.  If you are using the Reverb channel, the first, third, and fifth preamp tube (counting from left to right) are involved in that channel: the first is the phase inverter, the third is the second gain stage, and the fifth is the first gain stage.
Try a 12AU7 in 1, try a 12AU7 or 12AT7 in #3, and a 12AY7 in #5 for starters(my favorite combos) and experiment with various combinations of these in differing order until you find a combo you like tonally. If you can find a couple each of Electroharmonix 12AU7 and 12AY7 (they're cheap and decent) and experiment you'll likely find a winning combination.
For more info on the preamp tube layout of Fenders and tubeswapping see Mike Kropotkin's great page:
http://www.kcanostubes.com/layout.htm
Hope this helps!
Zig