In my experience, current-production tubes have been far, far more reliable than old-stock (new or not). This has primarily been with Russian Tung-sol and Gold Lion tubes, which are both the sort of mid-to-upper range of current production. I don't expect that the lower cost JJ, EH, or basic Shuguang would necessarily be as consistent. Having gone through hundreds of tubes in untested batches, it is exceedingly rare that these new tubes will exhibit electrical noise and even more rare for them to fail.
Also having gone through hundreds of old-stock tubes in tested and untested lots, I can say that it is much more effort to find tubes that meet my standards for low noise and microphonics, especially if I'm looking for a pair. There is also a higher likelihood of a tube testing well and developing noise after it's been shipped. Having the tubes pre-tested by the vendor sometimes helps reduce the instances of noise, but sometimes it doesn't make a difference. My testing procedure is: external burn-in period > Maximatcher testing > in circuit listening test #1 > in circuit burn-in period > in circuit listening test #2.
While certain old-stock tubes can certainly sound great and often sound better than new-production, I find that Gold Lion and other brands sound excellent and allow much less worry about noise, so I'm on the same page as millercarbon .
When you're buying a new amp, would you prefer the manufacturer use current production tubes as stock, significantly reducing the chance of tube noise in your new purchase, or would you prefer the manufacturer try to install old-stock tubes, though it's more likely that you'll have to deal with a noise issue?
Also having gone through hundreds of old-stock tubes in tested and untested lots, I can say that it is much more effort to find tubes that meet my standards for low noise and microphonics, especially if I'm looking for a pair. There is also a higher likelihood of a tube testing well and developing noise after it's been shipped. Having the tubes pre-tested by the vendor sometimes helps reduce the instances of noise, but sometimes it doesn't make a difference. My testing procedure is: external burn-in period > Maximatcher testing > in circuit listening test #1 > in circuit burn-in period > in circuit listening test #2.
While certain old-stock tubes can certainly sound great and often sound better than new-production, I find that Gold Lion and other brands sound excellent and allow much less worry about noise, so I'm on the same page as millercarbon .
When you're buying a new amp, would you prefer the manufacturer use current production tubes as stock, significantly reducing the chance of tube noise in your new purchase, or would you prefer the manufacturer try to install old-stock tubes, though it's more likely that you'll have to deal with a noise issue?