6SL7 in a Tweed Deluxe Clone?

[NBlair930]

I have some converters which enable a 6SL7 (RCA Red Base) to be used in place of a 12AX7 in a Tweed Deluxe Clone. Anyone ever try this w/ tonal success?

[Old Tele man]

...another flavor of chocolate.

...meaning: if you like chococate, you'll like it; if not, you won't.

...they're close (same transconductance values) but not identical tubes:

_6SL7: mu = 70, rp = 44K, gm = 1600 micromhos
12AX7: mu = 100, rp = 62.5K, gm = 1600 micromhos

[conundrum]

I have a tweed deluxe that runs on 6SL7's. It actually dosen't sound that much different than the 12ax7 version. It's currently in the 5E3 format with a cathodyne phase inverter. Beforehand I had it set up with a paraphase inverter ala 5C3. The difference in phase inverter circuits made a huge difference. The difference between the two tubes...not so much.

[UR12]

I have some converters which enable a 6SL7 (RCA Red Base) to be used in place of a 12AX7 in a Tweed Deluxe Clone. Anyone ever try this w/ tonal success?

It's really really hard to find a 6SL7 that isn't microphonic. I have had some success with some of the new Sovteks but the NOS ones are hit and miss at best. You may have to go through a few dozen to find a really good one. Having said that they do have a nice tone. If you are trying to use it in a hi gain amp you may have problems with the microphonics and they can squeal like a pig. Running them in a Deluxe circuit may work.

I have a design that I run a 6SJ7 and a 6SL7 and it seems to work very well but I have tried to reach a compromise with the gain.

Here is a clip of of the amp with some chickin pickin using a Tele recorded using a sm57 and a Mesa 1 x 12 cab. Kind of a Brad Paisley tone

http://users.zoominternet.net/~jdhall/amps/sample2.mp3