Preamp with Aleph 5 and Thiels

Aleph 5 has a neutral, detailed sound. Lacking body.
Thiel is also neutral, detailed sound. Would make use of tube or beefy amp to give it a fuller sound.
Personally, I'm not very comfortable with the two combo.
But ymmv.

I sold THIEL's for many years, Threshold Amps then, which were Nelson's first company, I believe.
I really liked using a tube preamp with solid state amps--to give a rounder sound, smoother upper midrange to the solid state of the Threshold.
The Pass is much more refined than the Threshold--but still, IMHO can benefit from a really good tube preamp--depending on one's taste, certainly.
Without checking for a mismatch of impedences, you may consider a cj pre, or a VAC pre with this combination.
Good luck and good listening.
Larry

I agree with Unsounds point, it seems you need another amp to drive the Thiels to their best - it is a great amp, but it really is not great at delivering current, a bit like a tube amp, and the Thiels need current and more watts to sound their best, changing preamps is not going to change that.

I agree with Pubul and Unsounds about the match between the A5 (which I currently own) and the Thiels (which I have owned in the psat, but not together and a different model). If the A5 had more power and more current, I think it would be a good match with the Thiels more strident and detailed sound (which is what I like about Thiels - great speakers FWIW).

I am running the A5 wih Gemme speakers, which basically use the same drivers as the Thiels, but a tad more efficient. I also run an ARC preamp (LS16II with the "supertubes").

I would never say the A5 lacks body, just the opposite. And I am coming immediately from SET and before that high power high current Aesthetix/Krell FPB/Wilson W/P5.1. I went SET based on all the SET lovers comments on this site, that lasted about 6-8 months and I grew bored with the SET sound - to me I missed the excitement.

I am still not sure if I find that the A5 is a bit under powered for my speakers, as I am thinking I may want to push the music a little more forward. But a large majority of the time I find I really enjoy the performance of the A5.

So, its a tough call. Do you love the Thiel sound most? If so, replace the amp. Do you want the sound of the A5, replace the speakers. I think (for me) that a more detailed speaker (like the Thiels) go well with the A5. A soft speaker, with a "traditional tubish" sounding preamp plus the A5 would be too underwhelming for my tastes, lacking the excitement I am seeking.