David, my memory was fuzzy so I just dakked over to
http://www.traynoramps.com to look at the schematic.
Your amp has a special autobias circuit. It adjusts itself and you can't change it! Mind you, it's set at what Ray the designer happened to like but he's not a bad player himself so what the heck! :tongue:
That takes care of the power tubes. I really don't think that you'll notice much difference in head room with different output tube brands anyway.
As for the preamp tubes, going for lesser gain versions of the 12AX7 family is a good idea but you really have to pick a tube with a BIG difference in gain to notice any change. I'd try a 12AY7, also known as a 6072. If you were close to me you could come over and also try some original 12AZ7s and 5751s but close to home you're better off ordering the 12AY7 from thetubestore.com
Even if it doesn't do exactly what you want as far as headroom I'll bet you 2 beer that you'll like it for some sounds anyway! 'Course, you'll have to come to my town to collect! :wave:
There's a lot of talk these days about all kinds of sonic differences between brands but I doubt if many folks could consistently hear them blindfolded after 3 beer. There are crap brands of course and one or two that sound a bit better than the rest of the crowd but maybe not worth all the extra cost.
I keep 12AX7EHs in stock from ElectroHarmonix. They work well and have a bit of a Mullard flavour to my old ears. Middlin' priced so good bang for the buck. There are some new TungSol tubes on the market. TungSol was a great name in the old days. Someone bought the name but unlike some other manufacturers they also tried to build their tubes as close as possible to the originals, instead of just inking on the name to try to BS the ignorant. I've tried their 5881s from the 6L6 family and they sound GREAT! They are the first and only 5881s I've heard since TungSol was still in business that sound real good! They don't cost all that more either.
They recently started making a 12AX7 that sounds as good or better than anything else out there and is super quiet - very resistant to microphonics and vibration. Well worth trying.
If you do want to play with brands of preamp tubes remember that 99.99999% of the tone difference is not only subtle but to do with the very 1st preamp tube in the string, the one closest to the input jack. After that you'd need a NASA lab to measure it, let alone hear it yourself. Stores that talk you into a full set may not actually be trying to take advantage of you by selling needless extra tubes. They usually are just cocky young pups that believe their own BS! They think that learning brand name buzz words and how to solder on a plug to a cord makes them techs!
Don't blow the extra money to no benefit. You might get caught short when confronted by a new brand of beer to sample! :banana:
Have fun!
