Tubes for Modulus 3A

Tungsram 6922s are cool!!!

That's one tube I NEVER skimp on. Manufacturers used the 6922 because of its quality compared to a 12ax7 and such. Good 6922 can make or break a system. You don't need to break the bank but $100 pair is well worth it, amperex, mullard or such. I actually like Golden Dragons if you can find them.
Keep in mind that 6922's will last up to 10,000 hours. Much longer than other types.

I previously owned a Modulus 3. The prior owner inserted a brand new quad of National 6922 tubes. I got less than 300 hours out of the new tubes. They became microphonic. I sold the preamp and the buyer tested the tubes and confirmed they were spent. I think AI recommends Russian tubes which are known to endure inspite being run at the limit. There's no reason for a preamp (properly designed) to cook tubes this way. Not meaning to put down your choice of preamp - they do sound nice. I just could not see retubing yearly. Mullards or Amperex may sound nice but probably will not last long in these preamps. A costly affair over time.

Here are the ones that Kevin Deal recommends from Upscale Audio. He has never steered me wrong over many years and many many tubes:

http://www.upscaleaudio.com/Russian-6H236922-Type-3_p_49.html

Like it or not you have to use rugged tubes in the AI. Unfortunately most of these are threadbare Sovtek types, including 6h23's (which I use in my ARC SP10 because like the AI it also requires rugged tubes). You might try some EH6922's. They have very different tonal balance than the Sovteks and might work in the AI. Since I believe these were the tubes which were OEM with Raysonic's you might just have some on hand to try.

How I solved my problems with the sound of 6h23's in my ARC was to find my 'warmth' in my phono cartridges, or tubes in DAC's or CDP's. For example with your stuff I'd try some EH6922's in the AI and some JJ/Tesla 6922's in my Raysonic. I'm familar with the sound of JJ's in the Raysonic (128) and they can sound quite lush. That Raysonic might just be the source of the warmth your system needs.

FWIW.