I have no Bat,
No Hallcro,
I know a preson with the Dartz,
I do have a one off ultramodded ARC SP6B last altered circa 1980, with a phonon that has approx. 200db of gain. The gain selection is soldered in the high position the switch byopassed. To get somethging resembling a noise floor it is clearly to much for but about one in a thousand 12ax7s quiet enough to tolerate. This kind of ultra low noise tube has yet to classified there are only few electron particle accelerators large enough toidetect the subtle vibrations that each tube naturally resonates at. Then assembling six would need six such tubes in a constant state long enough to find them makes it imposssible. It is also best siuted to nanovolt output cartridges the upside is that no a step up transformer is needed.
I have a very rich almost class A sounding ARC power amp the rare D100B. A solid state amp that was given up for dead a few years ago but judiscious small quick fixes have kept it going. Also circa 1981.
Absolutely nothing by ARC starting with the word reference. I have pleasant system of modestly priced gear with very few extravagances I think it sound great.
The one truly extrvagant part of my audio gear is a pile of 6 to 8 linear tracking turntables most don't work or if working don't sound very good.
So that leaves my good tube collecton. Do you have any gear that uses 6SN7s. I have a large variety and some of the best. 5751s, 7316s and other 12AU7 subs, And finally a goodly number of 12AT7s, 801s TFKNs, Brimar T brand 6060s and so on.
Finally some good copper braided wire reminding one of Jena lab cables.
Sorry but I'd have to refer you to the NJ Audiophile group. I was a member breifly.