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5 of the 6 tubes in the ARC are 6H30's, which are not really conducive to tube rolling. NOS 6H30's mean stock from the 1990's, unlike NOS 6DJ8's, 12AX7's, etc, which can date back 50 years or more.
Also, AFAIK, the former Soviet Union is the only source of 6H30's. Many countries manufactured 6DJ8's, 12AX7's, etc.
So figure the ARC Ref 3 will save you the headaches of tube rolling. Yes, tube rolling can have some positive benefits in the right situation, but it can also bring headaches as well.
There's a lot of hype on the 6H30 DR tube. When I had a BAT 31SE, I had a quad of DR's. I also had a quad of the Sovtek hand picked from Upscale Audio. I really had to sweat to hear a difference between these two and ultimately I concluded it was not worth the effort to try.
The difference between tubes in the 6922 family is huge. And with the new Aria WV preamp, the designer allows for these as well as the 6H30 and 12v based tubes like 12au7, E180CC, 7062, 5965, etc., in the line stage. After 2 weeks of trying 20+ tubes in the WV's line stage, the 6H30 came in nearly last place. Only a couple of 5963's fared worse and I concluded this had more to do with the gain structure of these tubes; the designer noted this tube might work but he had not tried it. A particular 7062 stole the show even over my coveted Amperex 6922 PQ pinched waist pair. And a couple other 12v based tubes were just behind the 7062.
Tube rolling can be a headache if you can not get off the train and be content with a favorite set after several trials. But this is no different than the obsession with changing cables every few months.
Everyone has different goals, ears and systems. Some systems won't resolve the differences between cables, tubes, etc, and some can't hear, or perhaps don't know how to listen to the various changes that component swaps can make. I've got some Ken-Rad(bottom getter) JAN CKR/6SN7GT's that sound identical to my TungSol(round Plate)JAN CTL/6SN7GT's, BUT- the TungSols give me a few more feet of sound stage depth(as drivers in my Cary mono-blocks). I have no doubt that 6H30 tubes hand picked by Kevin(I recommend his services often) would have performance very close to that of the DR's. BUT- What if he went through a batch of the DR's and hand picked a few? I've owned my BAT VK-D5 for a few years now, and have the bufffer stuffed with six Siemens CCa's(1960's,NOS 3yrs ago). I won't be having the unit upgraded to the Six-Pac/SE for that very reason(I'm too attached to the openess/transparency/ambience recovery/top extension w/o grain, glare or sibilance/solid, well defined bass of my CCa's). I've never found tube rolling to present any problems in the least, having always done my homework in advance. The rewards always have outweighed the efforts by a very wide margin.
Yes, there are 2 or 3 different styles of 6H30's at this point, the DR and the EB are the only ones I'm familiar with. They are all Russian sourced though, AFAIK. There are no Mullard, Siemens, Telefuken, Amperex (typical highly sought after NOS manufacturers) 6H30's.
I have done some tube rolling, and I find that there is a much larger sonic difference in 6DJ8, 12AX7 and 6SN7 variants then there is in the 6H30 class. Yes, you can spend more money on the DR's, and there is a subtle improvement, certainly not on the scale of going from a Sovtek 6922 to a Amperex 7308 PQ or a Siemen's CCa.
If you want the VERY best 6H30, Victor Khomenko of BAT will sell you some of the oldest NOS 6H30-DR's from the 80's for $300 a tube. I wouldn't recommend it, but some will I'm sure.
Actually John (Jafox), changing tubes is a bit more of a headache for me than changing cables. My ARC Ref 3 has 20 screws on the top plate, and I have to unplug all the interconnects and power cord to move it in and out of the rack to change tubes. Interconnects I can change without a screwdriver, moving a chassis or involving any other cables. :)
Tube rolling in my BAT VK-75SE amp is much easier, but again, not as rewarding as rolling KT88's, 6550's or 300B's.
The Russian tubes (6H30's, 6C33C, etc) tend to have better dynamics, definition and extension then the other types, though they are not quite as full or sweet sounding, IMHO.
The other plus for the Russian types is that replacement tubes tend to cost less.
I agree that introducing vintage 6DJ8 family tubes in, say, an ARC PH7 phonostage, can yield a much broader range of results (almost all favorable) than rolling 6H30s.
I did a comparo of stock 6H30-EB, cryoed 6H30-EB, and 'NOS' 6H30-DR in a CJ ACT2 and in the phase inverters of a CJ Premier 140. The DRs came from Evgueny at ConusAudio. Did I hear a difference? Yes. Was it significant? I don't think so. Maybe ... maybe ... a little more top end extension. Changing the Premier 140's single 6922 driver tube made a larger audible difference than rolling the 6H30 in either it or the ACT2.