Larry:
That's a pretty deep question. It depends on your speakers, front end, music preferences, etc. What kind of sound are you looking for? In 6SN7's Tung Sol, RCA, Sylvania and Raytheon are gold standards, but each will give a different sound. The RCA's are the most romantic tubes, and Raytheons are closer to solid state. In 6922's, Telefunken, Siemens 7308, Amperex 6DJ8 or 7308, Tungsram and Mullards are all good, but beware of fakes on e-bay. Each will give a different sound. Best thing is to counter-balance 6SN7 and 6922, e.g., RCA 6SN7 with Siemens 7308 or Amperex 6DJ8, Raytheon with Telefunken.
That's a pretty deep question. It depends on your speakers, front end, music preferences, etc. What kind of sound are you looking for? In 6SN7's Tung Sol, RCA, Sylvania and Raytheon are gold standards, but each will give a different sound. The RCA's are the most romantic tubes, and Raytheons are closer to solid state. In 6922's, Telefunken, Siemens 7308, Amperex 6DJ8 or 7308, Tungsram and Mullards are all good, but beware of fakes on e-bay. Each will give a different sound. Best thing is to counter-balance 6SN7 and 6922, e.g., RCA 6SN7 with Siemens 7308 or Amperex 6DJ8, Raytheon with Telefunken.