VAC 70/70 mk3 tube rolling question

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?

Interesting and valuable info.

The RCA red base is a 5692 which requires less voltage. But it's good to hear VAC is ok with running all versions of the 6SN7.

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...

@roxy54 
Almarg is no longer a tube guy, no more VAC. Can you believe it?
Of course, his wisdom is always welcome.

@roxy54 ,, 
Oh yes, I was agreeing with you.

I wish Al all the best, he is sorely missed on the forum. My thoughts go out to him for a speedy recovery.

One pair 6SN7 are for the gain stage, the 2nd pair are the phase inverters.
Example; RCA L, R gain stage.
Raytheon L, R phase inversion (drivers for output tubes)

Good luck, @yuhengdu_tiger . You have a beautiful amp. And your 2 sets of tubes should work well together.
🤞 fingers crossed.

@yuhengdu_tiger .
Yes, I agree. Nice work finding that pic.