One more thing Joe, if you like clean sounds and detail:
I usually fit at least one 5751 type pre-amp valve in my larger amps to ensure the quintesential Fender/SRV sound. These are a 12AX7 type, but with only about 75% of the gain. They add a lot of detail and articulation to your sound, especially if you put one as the first valve in your pre-amp stage.
I have tried them throughout my Fender 'The Twin' and Laney LH50R, but when used all the way through they 'cool down' the gain channel too much.
Whilst I do not play Stevie Ray Vaughan stuff, I read with interest that he kitted out his Fender amp's pre-amp stages throughout with 5751 types to get that massive clean sound, (even with a tube screamer pushing up the front).
Each one you use tends to bring the overall volume down a bit, but that does not sound like it would be a problem to you.
In the end, (to get the best of both worlds) - I ended up just using the one 5751 at the first input stage of my amps and then nice clean sounding N.O.S 12AX7 types for the rest.
If in doubt about voicing and choices, contact Derek at watfordvalves.com to ensure you get the right combination. They do tend to be the BKP of valves and speakers, as they test a sample of their products in actual amps at full throat as well as the electrical tests.
Hope that helps,
:D
FF.
