Psvane CV181 TII in both driver and splitter on VAC Renaissance 70/70?

Your, "...other issue..." is addressed; in the third paragraph from the bottom, of this tube survey/comparison:          http://www.dehavillandhifi.com/6sn7_vt.htm        A well-chosen, NOS pair of decent 6SN7s would benefit your presentation.     A nice amp, like your VAC, deserves good tubes.

My preamp has two pairs of 6SN7 signal and driver tubes, and while I enjoyed splitting tubes with one pair of new, and a second pair of my best NOS tubes, what worked best was two very closely matched pairs/triodes of the same brand of boutique tubes.  The tubes are from a related company who ended up selling their tooling to PSVANE, running a quad of them now, sound fantastic. The NOS are now sitting in a box.    

Just do it! Better tubes are better than what you've got. 

I’ve always used two different kinds of input tubes (NOS) in my amps. Both tubes will contribute their characteristics to the overall sonics. For example, a Sylvania (transparent, detailed) in the gain stage and a RCA (lush, warm) as the driver/phase splitter. The best of both worlds.

Or you can have a different approach. I like transparency and realism so I'm using a pair of Sylvania VT-231 with a pair of Ken Rad VT-231. The result is neutrality and realism combined with the KR's deep bass and more forward presentation.

I really appreciate all the input here.

Well, I have some sylvanias and rcas arriving soon.  And hopefully I'll get to drop them in soon, I'll prob start with an RCA/Psvane combo, then try the Sylvania/Psvane.  Lot's of combos to try out, but some break in first.

The second set of Psvane is tempting, and I may  just have to roll the dice on an order, and play with them when / if they get here.  But maybe these NOS will be a great stopping point.

I'll keep you posted!

Vineland, can you describe the change in sonics you're experiencing with the Psvane in the amp? 

Btw, the 70/70 is a beautiful amp. 

Hi Lowrider,

The first difference was vocals - for example in rocks off or tumbling dice on Exile on Main Street, they'd been recessed a bit, almost lost in the mix, with the electro harmonix.  I'd say a certain natural prominence I'd always heard was gone.  Also in From Her to Eternity by Nick Cave.   When I put the Psvane into the V1 slot, I didn't hear a difference.  When I put them into the V2, it was an immediate improvement.   I'd also say the soundstage expanded, and some textures on the vocals were there that weren't there before.

Additionally, the sound was not as bright, which in my system with Thiel 1.6, brightness can be an issue.

btw, I also went from the 8 ohm to 4 ohm taps, and that's really helped on the coherence.  The Dvorak dumky trio on a recording by Trio Wanderer has more image solidity and naturalness using the 4 ohm taps.

Thanks for your kind words on the VAC.   It's a fantastic amp, and I'm just tuning it right now.  I feel I can get more out of it.

Thanks for the reply. You've experienced the same issue as me with new production Russian tubes. They don't reproduce a smooth, realistic top-end.

Keep us posted on your next tube roll.

I'll keep you posted.  May be a break in period, for the NOS as well as the psvanes.

@vineland are you still feeling good about the PSVANE CV181-TII tubes?  Are they still sounding good?  Lasting  longer than 1-year for you?

Ordered a matched pair.  Hope to learn more first hand in 30 days; after shipping and a few weeks of burn-in.