Five 6AS7g type tube comparison

Someone else will need to take on the 6SN7 challenge. Not having anything that uses them they are not part of my tube stock.

 

@atomicbob , I have been following the TA-66 threads and, based on your reports, a couple of new-looking T6080s arrived today in a HUGE box inside of a HUGE box. I am not experienced with OTL amps and have just a few tubes for the TA-66: the OG Shuguang 6N5PJ, a Sovtek 6AS7G, and now the T6080. I love the "grooviness" of the Shuguang and the crispness of the Sovtek, but the T6080 really seems to get the best out of my 600s: stuff that would feel cramped now has space, the mids are just lovely and a touch magic, nothing is smoothed over but nothing hurts, and I feel like the bass is as articulate as I have ever heard on the 600s.

Thanks for all of your informative and fascinating work on the TA-66 and on measuring these tubes!

My chain is Qobuz>HQPlayer>Geshelli J2S 4499 with Sparkos SS2590 stack>TA-66>HD600/6XX/ZMF Auteur Cs

Just as I was typing all this down, Queens of the Stone Age's "No One Knows" came on: crunch, punch, present, everything in its right place, super legible and exciting.

 

You raised something interesting here. I'm wondering if OTL actually gives you a better sense of the tube's characteristics than OPT, because the saying is that OPTs will impart more of its sound than the tubes. But then I remember Purr1n said that the correct caps in line of the tubes will make or break the sound.

 

I can't speak with any authority on the matter. Some tubes are better than others, for me anyway. But they should all mostly be good enough, I recognize, for whatever reason, maybe just EQ. I defer to others. For SET it seems like some of the greater amp designers have rolled a great amount of transformers and know what they are looking for - for sure. For OTL I briefly owned the TA-66, for a long time owned a crack and a euforia - both of which I sold and the TA-66 returned. The crack responded to tube changes a little more than the Euforia, it seemed, but a standard crack apparently responds to tube changes quite significantly compared to speedball (which I owned) - and that has pretty cheap parts.