new 6h23 tubes vs nos telefunken or mullard 6022's

NOS are nice, but finding good, low noise, matched, linear, reasonably priced NOS can be an exhausting challenge that often ends in disappointment. There just is not enough NOS supply to screen and weed out the "boutique junk". The current manufacture tubes are often times much more robust than NOS. Some of the more "demanding" gear that eats NOS like candy performs better with current production tubes. I haven't given up on NOS, but I've found that it's much easier and less costly to go with current production low noise matched tubes and still be extremely satisfied with the sound. The most consistent sounding NOS that I have found are the TFK E188CC, TFK CCa and the Amperex White Label PQ 7308 along with its re-branded brothers. These demand prices up to 4+ times what you will pay for a screened current production. The Ei Elite 6DJ8EG was a pretty good tube after you got them sorted out and they survived burn in without shorting, but Ei is no more. There are several current production Russian and Chinese equivalents that perform quite well. If you want to give current production a try, contact Kevin at Upscale Audio or Brian at DIY Supply.

I beleive you can find a better source for tubes than Upscale Audio. If you want to deal with a rude, pompous individual call Kevin.