Re: Superior Tubes?
Tubes...especially pre-amp tubes, are the 2nd biggest change in tone you can make to your amp, IMO, after speakers. You can go brighter, darker, more gain, less gain, open, more compressed...it can go on and on. Experimentation is the key, and for the most part pre amp tubes are cheap enough to experiment with. At one point I had a stock of about 15 different pre-amp tubes, ranging from cheap Mesa and EH tubes thru a $90 NOS mullard.
I have really found a happy medium between cost and tone with the Groove Tubes pre-amp tubes, specifically the C's, which are the 9th generation Chinese, and the "M"s, which are the Mullard reissues. I have A/B'd them with some of my good NOS tubes including:
Mullard
RFT
Bugle Boy
RCA Blackplate
Siemans
GE (white letter)
and a few other's I can't recall right now. Bottom line is the GT's sounded about 90% as good as my best tubes NOS tubes, and downright better than some of the others. I still have my stock of NOS tubes, and I need to get back in the habit of buying one or two every so often, in case production tubes take a dump again, but the GT's are great, affordable and easy to get.
Long story short, take $100 , buy a handful of different tubes and experiment. It will be the best $$ you've ever spent.