VAC 70/70 mk3 tube rolling question

Use matched set of Rca, matched set Raytheon.

The input circuitry of the Renaissance Seventy/Seventy is derivative of the unique Williamson circuit, which provides pure, direct coupled, inherently balanced input amplification and phase splitting. Type 6SN7/5692 octal twin triodes do the honors.

https://skyfiaudio.com/products/vac-valve-amplification-company-renaissance-seventy-seventy-70-70-du...

@lowrider57  Thanks for the helpful information. Forgive me as I don't understand all the details of the williamson circuit and I can't upload photos here. 

So basically there are four 6sn7 tubes in the front row of 70/70. Assume they are V1, V2, V3, V4 from left to right. My understanding is that V1, V2 are for channel 1, and V3, V4 are for channel 2, is that right?

My question is which ones are for gain stage and which ones are for phase inverters? ( If my above assumption is right, is v1, v3 for gain stage; v2, v4 for phase inverters ?) Thanks!  

Correct, V1,V2 for left channel.
V3,4 for rt. channel.

Sorry, I can't help identify which is gain and which is driver. Hopefully a VAC owner will chime in.
But, designers like to keep things organised, so I would guess that the gains are V1 and V4. Or they could be V2 and V3.

Have you looked for a user manual online?

Call the VAC factory and speak to Kevin or Brent. I believe the order will be the two most outside (L and R) should match and the two inner should match, but my memory may be incorrect.  They are always happy to welcome new members into the VAC family and will share where they believe each pair will work best (splitter or gain) and exactly which pair of tube sockets is each... so yes one of each for each channel but you need to know which sockets are what in the circuit. If your “red base” RCAs are the 5692 military versions I would suggest those to be in the amplification section and use the others as the splitters.
The manual is on the VAC website if you have not already seen it. http://www.vac-amps.com/manuals/Manual_Ren70-70.pdf

@rodman99999  Thanks a lot for these info! I purchased my two pairs of 6sn7 from Brent at audiotube.com. He helped me picking up those sets. Personally I don't have a lot of experiences with tube rolling.