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.
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.