Which tubes are the best?

@akiravelvet,
Obviously Brent does not like new tubes. His business is to sell NOS :-)
I have not heard NOS in my system. But after hearing the difference between the new Mullards and the Psvane/Genalex Gold Lions, I am more than happy with the new tubes.

If « really » NOS tubes last between 6000 and 10000 hours and a new one only 2 or 3000, which is the more expense ice in the end ?

Sorry, just a novice here. Got a PrimaLuna amp that started to whiz a little so I went to get some new tubes. (This was just two weeks ago) After some research and reviews choose the "Natural Sound 6CA-7" which is a Shu Guang Perfect Pair. So while I was in the mood to spend some money I figured what the heck, I'll replace the 12AU7 as well. Landed on the Gold Lion Genalex ECC82/B749. Yay.
So put them in and loaded up some of my best music recordings. Well. Spent the next three days relistening to music that literally blew me away anew. I thought, dang, these Double Impacts ARE pretty good. Dang, this PrimaLuna IS pretty good. Everything went up to like double as good. Nothing changed but the tubes. And quiet, wow. But like I said, I'm no expert but I know what my ears hear.

My amp calls for 6550 output tubes so I auditioned them against a couple of other brands. I ended up preferring the Gold Lion KT88s by a significant margin so I bought them. And then I bought a back up set!

But that was on my power amp (CJ Premier 11a) - YMMV with other amps.

   Fist off , I’m a strong advocate of premium NOS driver tubes . Yes they are expensive, but they’re  a long living tube and worth the investment. I must disagree with the “ JJ “ crowd , as my Rogue pre amp came with JJ 12AU7’s . I tried numerous tubes , with RCA being the best domestic and Telefunkens bettering everything I tried . I haven’t owned your particular amp , but I’d speculate that in a 3 driver tube configuration,  your middle tube will influence the sound significantly more than the other 2. That’s how it works in amps like  Bob Latinos. The sound is all based on system synergy , room character , and your taste . So you have driver tubes , power tubes and a reciter tube . Your driver tube(s) will have the biggest change in tonality . Your power tubes will matter in accordance with what speaker you have . Now I have about 10 different driver tubes , Including RCA, Seimens silver plate and CCa, Tekefunken Tektronix, G73-R, and standard, PHILLIPS, EI , and I can keep going . Now as for power tubes I have new production JJ, Gold Lion, Tung Sol and the Psvane Ti. NOS power tubes GEC KT88 and KT 66, Tungsol 6550 3 hole , and SED Winged C . And about 6-7 reciter tubes , mostly NOS . So here’s my recommendation. Driver tubes on a budget , Tungsram NOS , Or Tesla ( nos ) . Telefunkens are the best . I’ve tried nos Mullard and it’s like throwing a blanket over my speakers .  The sonic signature of all drives tubes is perfectly described on Brent Jesses site. Then for power tubes,  new production Gold Lions are the overall best at providing a flat response  and still provide good bass . In my system they are only bettered overall by KT -120’s and SED Winged C’s . The higher level Psvane Ti’s are too bright . Now with your rectifier tube , it’s important to see what your amp can accommodate. Mine will handle many . I have all of the good ones except a NOS GE 274b. I prefer a 5U4GB over the higher voltage 5AR4, as it smooths  out my system . So for you a modern Gold Lion or a vintage RCA or TungSol coke bottle if it’s compatible with your amp . About 15 years ago, when I got back into tubes, I had an Antique Sound Labs 30 Wpc integrated that had a SS power supply . I went with Tungsram drivers and Svetlana ( SED ) winged C EL34’s and the sound quality improvement was substantial. So junk any cheap Chinese tubes , skip over JJ’s and go to something that you can live with . Happy hunting , Mike .