Tube vs Solid state for Preamp

I’d consider some tube rolling with the AI before giving up that preamp.

Definitely stay with tubes if a Krell 350 watt amp can't do low end it's on the amp not your preamp. Are there better tube preamps than the AI? Sure do you have a budget in mind?

Backert preamp as superb.

Funny this post came up, wondered when it would again.  I just spent the last 90 days re-evaluating my SS preamp to my 6SN7 based tube preamp.  Both are nice in different ways, however nothing about the SS preamp can replace the sound stage, layers, 3d imaging of the tube preamp - IF that's what you are going for. 

I always prefer tubes, in the past units all were using 12aux, 12atx

My current Cayin Integrated uses 6SN7 and 6SL7’s, I really like their sound. Based on their sound, 2 of my friends changed their Preamps to 6sl7/6sn7, both very happy with them.

Various tubes definitely sound different, I bought (6SN7 or 6SL7’s too lazy to look it up) from Brent Jesse, one pair sounded awful to me (compared to the original Cayin branded I blew up). He had me break them in for 60 hours (no signal, just on), I still did not like them, he let me exchange them, I got lucky, second choice, half the price, they sound terrific.

Meanwhile, someone changed their OEM Cayin tubes to a different type, and listed his Cayin tubes on eBay. I jumped on em.