You are ignoring the fact also that tubes from different manufacturers of this tube sound different as do they over the period during which they were manufactured. For my old Supertek Syrah, at one time I had 12 different tubes with some clearlly sounding better, not that I recall which anymore. This is the joy and terror of tube rolling.
I have no conflict of interest to disclose. Tubeseller.com a dealer I think sells 6SN7S exclusively, has a lot of information on his site. He has credited a very long thread from the headphone site hed-fi.org which he abstracted. You would do well to read them. The other sites that I recall which have the general info you want are vintage vacuum tube services, and Brent Jesse's site which has a new name. Mr. Behr is quite knowlegable as a collector of 6SN7s amongst other things and I have benefted from him. But I don't think he has a BAT. The differences between the sonics a tube roll will make depends on many variables. Some amps don't respond or very little for instance my SP6B ARC preamp is difficult to manipulate. That said there are tubes which yeild a particular sonic signature on no matter what system it is used on...e,g. A Ken Rad 6SN7GT is very bassy.I am sure Victor at BAT will recommend a Russian tube.
I recently bought a bunch on N7s to a friend's place who has a Supratek. He settled on a very immediate, quick and a slight mid bass emphasisizing tube, the Sylvania 6SN7WGT. You may want a richer tone? The list is endless as youn already know.
Damarodona: "After all those I 've read in the past about BAT's tubes and voltage I really wonder what type of 6SN7 is the right one for a VK-60 ?
My question is only about voltage."
Gentlemen, Dama is asking only which 'N7s are suitable for the Voltage that BAT designed into the amp, NOT which ones sound good.
Dama, which tube type came with the amp? Have you yet asked BAT which tube types are suitable?
And come on guys...we don't need inane notes on the cost of capacitors v. frontend tubes; that's called hijacking a thread.
I asked them months ago and their answer was:"We do not get involved in the aftermarket tubes, we just know what we sellworks, other brands may have problems holding the voltages"
Yes but IMO a pair of Raytheon 6SN7GTB can blow away any russian 6SN7.
And unfortunately almost all NOS 6SN7 are expensive. So, in a fear of a problem because of voltage, we (BAT owners) must know which type of these 6SN7 can handle 500v or 600v...?
It can't be a secret!