Tube swapping in amps and preamps

Put the best tubes you can in both. What "best" means will depend on your preferences, system synergy, and budget. I have found NO components that couldn't be improved by exceptional NOS tubes. Some new production tubes are quite good but almost none can match the best of the best when tubes were king... (recent WE excluded IMO).

Here's a thought, perhaps you should do neither! Pre amp tubes, amp drivers and power tubes all contribute substantially, and probably equally, to the sounds you hear. You need to decide what you want to change, sound wise. The sound you want to hear will determine your selection. Personally, I would start with my pre-amp and if that didn't give me what I wanted I'd start working on the amp, starting with the drivers. Leave the power tubes til last (due to the expense involved - but if you have smaller power tubes (read less expensive) you may have a couple sets of new production tubes about for contrast purposes). There are new production tubes that work well in amps but not so well in pre-amps. There are NOS tubes of moderate price that can work as well in either and there is some dreck. Then there is the expensive NOS stuff, which should be approached with caution, unless you are absolutely sure it will work well in your application. Usually its not a matter of "tube A" being better or worse than "tube B" its about how the tube will compliment your unit and your system and give you the sound you want to hear. Caveat emptor.

I'd agree to some extent with Jwaugh's statement regarding NOS tubes. I would add that there are some instances where current production is close enough to NOT warrant the very significant added cost of NOS, not to mention risk if you are not buying from a known seller. There are plenty of boutique tubes available in the big bottle triode category that are current production, though are just as expensive as NOS.

Given the choice between spending $ 100/tube on some GEC KT88's or pick up a quad of JJ Teslas for just a bit more than one GEC might cost, I'd prefer to spend the extra money otherwise as opposed to the marginal improvement the GEC's might render. Same goes for Mullard EL34's. Svetlana's brand new 300B tube is supposed to equal if not surpass the WE according to the Stereophile shootout (as reported in a follow-up). Sovtek's 2A3's are excellent tubes in that category. I just had some vintage Sylvania's (the good ones) to roll against them, and though marginally better in most areas, I didn't feel they were worth the added cost in my PP 2A3 amps...perhaps in the SET amp I compared them on. NOS construction and materials may have a leg up on most current production tubes, but I think each person should weigh the cost to the (degree of) benefit. I've heard bigger gains by improving the tubes in a preamp section than I have in swapping the tubes in amps, but I don't think this is a rule by any means. You may want to list your pre and amp and the tubes you are using and state what you are considering changing/investing.

Marco