There is a good chance that you will be dissapointed with NOS tubes if you try only one brand. There is no reliable predictor of how a specific NOS tube is going to sound in your system without trying them out. Hence the term "tube rolling" which is the act of substituting several brands of a tube type in your equipment to find the best sound. This can become very costly depending on the number of brands you try and how exotic or scarce the tube brand is. For example, you could spend upwards of $200 on a matched pair of NOS Amperex 7308 gold pins and there is no surety they will sound good in your system. You can increase your knowledge on the NOS subject by visiting the Vacuum Tube Valley website. They have devoted magazine articles to the 6922 tube and its close relatives such as the 7308 where they test as many as 50 different tube brands and vintages for sound quality, noise, and gain. The good thing is that they include recent vintage tubes in the articles such as the sovteks, the JJ's and the EI's. Again, this is a guide that will get you started but it is likely that the tubes they rate highly will sound somewhat different in your system. That has been my experience. In my opinion, tube rolling should be viewed as a seperate avocation within the audiophile world. You must be patient and expect to get some tubes that go bad shortly after installation no matter how well they measure. If this sounds fun to you, then go for it. Just don't expect to get the right NOS tube the first time around.
