Well it all depends on if your Tungs are true vintage or just reissues. The easy answer is for the stock R8 6SN7’s they are either not very good Russian (probably – mine were) or worse Chinese – so they aren’t good anywhere but in the bin. Now if your Tungs are reissues they aren’t much better than those stock R8 tubes, on the other hand if they’re vintage Tungs, then they’re among the best sounding 6SN7’s ever made and i’d put them in the Pre for sure. Now you might think i’m being hard on modern tubes – but remember the tubes ARE the Amp and i’ve listened to pretty much every common 6SN7 (and many rare ones), and quality vintage tubes beat the modern tubes hands down. Yes this is a very general statement and you will occasionally find a good sounding and reliable modern tube.
