12AX7 tubes for Music Reference RM-10


I looking to replace the 12AX7 tubes in RM-10 amp. Looking at the manual it says something about "V1" being grade AB and "V2" being BA. Below is a quote from them:
" Note that V1 is a RAM grade AB (section 1 selected for low noise) and V2 is grade BA (section 2 low noise). It is essential to have a grade A section as the first amplifier to achieve the very low noise of which the RM-10 is capable."
The question is: do I need some type of special 12AX7 tube? Do they have to be matched? Balanced? etc...
Any feedback will be greatly appreciated, thanks in adavance to everyone.
jmcp60

Showing 3 responses by gmuffley

Both halves of the tube are used. One section is a grounded grid voltage gain section and the other is used as a concertina phase splitter.
Both halves of the tube are used. One section is a grounded grid voltage gain section and the other is used as a concertina phase splitter.

Sorry. I meant to say grounded cathode--not grounded grid.