Shall I add a preamp to my setup?

I know you don't want to hear this, but the harmonically "thin" thing is coming from the Thiels; crossover and tweeters; its a constant with Thiel. I know you are not going to move from them, but down the road, when you are still trying to balance out the thin thing with wire, amps, etc. you may want to remember this.

If I had $6k - and that is plenty of cash to do a lot - I would go with a Shindo Augieres. Its a line stage that has a nice MM phono when you decide, if you do, to step into the analog waters. With all due respect, I understand that the Io is a nice piece, but getting a new guy into all of those tubes is not really a good idea. The Shindo is fantastic (see Art Dudley's review in stereopile (no, not a typo...). You could build around it for a long time and if you ever wanted to sell it, you would hardly lose much and it would sell fast. Which is the tough part; you have to be patient for one. The avg $ on one these days is @3000. Which, of course, leaves you cash for some other stuff, which brings me to...

I know that no one asked, but if I was putting a system together for someone, I'd do the Shindo pre above ($3K), the Shindo Montille 25W EL84-based amp ($3K), Shindo or Kondo wire (@1K-1.5K if you are smart), maybe a Cambridge CD player, and Living Voice IBX-R2 speakers (@4K), and then a nice intro analog rig after that. You might never come up for air.

Just some ideas...

Grandtech, on the VT-231's, if you don't shine up to the others, trys some black glass Ken-Rads.

I have a stash of the Sylvanias and Ken-Rads and always preferred the Rads. Don't know about the RCAs.

Let us know how it goes...

The black glass Ken-Rads, while a bit darker, are very expansive - assuming you get a good pair. The Sylv are nice, but IMHO just a bit less all the way around, just a bit, which adds up, of course.

My choice is the black glass Tungsols, but they are getting very hard to find.

On the Thiels, hey, if you love 'em, great! I mean that!