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...

Grandetech, I have a similar setup with yours in pre/pro and amp. It is good for HT, but the 2-ch performance is not very good. So I got a BAT VK-3iX. The 2-ch sonic got much better. However, it lost some bass and dynamics.

I did some research and found that some tube pre-amps, including my BAT VK-3iX, have higher output impedance levels. So I upgraded my BAT with their Super-Pak and Six-Pak packages. Both dynamics and bass improved quite a lot.

Then I thought it was still lacking harmonics for vocal, piano, and violin. After some research, I found that 6922-based preamps don't have the harmonics that 6SN7-based preamps have.

Then I decided to get a dedicated 2-ch amp. So I got a Counterpoint NP100 with 6SN7 in the gain stage and transistors in the driver and output stages. I really like my setup now.

So my recommendation is as follows.

1. For the tube preamp, you want to make sure that it has a low output impedance to drive a SS amp. Most tube power amps have higher input impedance levels than SS amps. So if a tube preamp is designed for tube power amps, it may not be sufficient to drive a SS power amp.

2. If you want to keep your Sim Audio 5-ch amp for 2-ch music, I would get a 6SN7-based preamp.

3. I also think your speakers are a bit too dry.

Hope it helps.

i have to agree with the bulk of posts above. For certain harmonic rightness, or richness depending on your view you cannot be without a tube pre amp. With that said the post regarding thinness with the thieles is something i have noticed on various brief listening sessions with thiele.

If you want most bang for the buck improvement id switch speakers first. Then buy a used tube pre. It may not be what you want to hear but its my candid opinion

I finally getting a Cary SLP-05 tube pre to see what my system actually got, maybe also upgrade the speaker cable from some DIY to Analysis plus solo crystal oval 8, by then should know if I have to switch the speaker from there, hope not. God bless me :)

Any comment if AP speaker cable will fit the Thiel 3.7?

RE pre
Congratulations.

I've only heard some talk of AP cables from those I trust... it wasn't impressive talk.

Synergistic Research offers a lot of bang for the $$$, as well as does Audience. I've 3 sets of SR speaker cables. All different itterations, in 3 different systems and couldn't be happier.