Atma-sphere amps best power tubes


This question has been debated before on A-gon but without a clear onclusion. I wonder, is it worth it, to upgrade from stock Russian or China output tubes (6as7g), to American NOS tubes?

It seems that everyone agrees that upgrading the Atma-sphere driver tubes from stock Russian/Chinese to NOS is well worth it. This is my experience also.

I am wondering about changing the output / power tubes too. I wonder if a change to NOS is well worth it also in the output case.

It seems likely, judging from my other equipment testing.

My Audiotailor Jade OTL headphone amp uses 1 6asg7 and 1 12ax7. No surprise - it sounds better with a good NOS 12ax7 compared to Russian/Chinese stock 12ax7.

More surprisingly, it also sounds clearly better with a NOS 6as7g output tube (General Electric US NOS). The improvement is largest with the driver tube but not so much behind with the output tube. Almost 50 50.

A lot of output tubes are involved - 28 tubes in my MA-1 amps. Changing them all is costly, and so I would like to know some user experience before I go into this.
Ag insider logo xs@2xo_holter
Try dome Sylvania Ws note not WGT ,  These have the renowned 'chrome dome'.  They are expensive but are very good.  The short bottle is relatively more common than the talls etc. and have been selling for unusually low prices of late -about $50  or slightly more for ea. .
Updating experience with NOS output tubes in the MA-1 amps (mainly RCA 6AS7G). I have had zero problems, no failures, over the last half year. This NOS set has now been running for close to two years. I enjoy the sound.
It's a very interesting combination of input tubes . Obviously highly amp specific. If you want clean crisp almost SS sound from a 6SN7 try  old stock Hytrons, avoid the CBS Hytron.
I have to chime in on this....

I just put some Shuguang CV181-Z tubes in my AtmaSphere UV-1 pre. Best 6SN7s I have heard, and by a mile.  CLARITY.  I also run M60s and will be trying to figure out if they'll fit. They are not shaped like typical 6SN7
@ bigboltz. Does the UV-1 transmit the character of the 6SN7S  really well when you roll them?