Shall I add a preamp to my setup?


I newly setup a system with Thiel CS 3.7 speaker, driving my Sim audio Titan 5 channel poweramp, source with Simaudio cd5.3, I am very excited with the 2 channel performance, but it seems lack of warmth of vocal and extension of high, not enough airly extensions, base is fine. I doubt my weakest link is the Sherbourn PT-7010A pre/pro, all the above new gear has pretty much break my bank, I wonder if I should squeeze the rest of bank reserve for a descent 2 channel preamp in order to solve the problem.....the other choice is a better CDP, can someone walked thru the similar path give me some advice?
grandetech
Those tubes should help a lot. they possess different attributes and should offset each other well. More ease would be gained using all RCA.... just something to think about.
Thanks for all your input and finally the Cary tube pre is installed with excellent result, its more harmonic on vocal, strings, piano, bigger soundstage, singer step forward to me couple of feet, last but not least, more airy and less harshness.

If I have to improve, thats the slight tip in the highs (I know its Thiel) and lower the signal to noise level (I can hear it with volumn tune to zero from 3-4 feet away), hopefully the RCA VT-231 coming in with resolve a bit. Any thoughts of other?

Thanks Jim, I am using Cardas Golden ref now. Put on hold for speaker cable unless a good pair of SR AR/RR comes up in agon.
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...
Asa, may I know how do you prefer Ken-Rads over Sylvanias?

I just love more and more to my system every single day, the SLP-05 is terrific in all area, hope rolling to the NOS tubes early next day will shine it up even more, I will let you know soon, thanks, ASA.

p.s. I don't mind the hiss at all, the music covers everything even no matter what volumn level. Jazz piano will bass and drums are top notch now...
update on tube rolling, Cary/Gerald has suggests to roll tubes on the buffer stage in priority, follow by the gain 4 tubes, so I am going to put the RCA vt231 pair in buffer stage and with sylvania vt231 to gain stage.

p.s. Thiel CS3.7 is such a revieling speakers, crap in crap out, with Cary tube pre, you get great resolution with terrifc warmth, muscical, I consider this is a true synergy and absolutely in love with the speakers now. I had A/B SLP-05 with SIMAUDIO P5.3RS, absolutely different league in terms of transparency and bass control, everything seems more clearer.