Choice between Pass Labs & Constellation amp

Here is input that is not exactly what you are seeking, but may prove valuable.  The Constellation amps were designed by Bascom H. King, a contract designer of considerable skill and pedigree in the business.

A couple of years ago he designed amplifiers for PS Audio that use very similar thinking, and incorporate a triode tube input stage, and they are marketed as "BHK Signature" products, being amps the designer was pleased to put this stamp on.  They are far less expensive than the Constellation line, and it seems that BHK might even allow that they are superior, if pressed.  I do know of one Constellation owner that sold them in favor of the PS Audio offering (their 300 Mono's), so they may be worth your adding to your list, and arranging a home audition is pretty easily done, I believe.

I have the 300 Mono's driving some TAD CR-1's and I'm done looking for amps.  They just draw me into the music with great emotional connection, even while punching the "audiophile" buttons of resolution, etc.  My 2 cents.

ibrrp 1

Thanks!  I will look check out  PS Auido's  BHK Signature amp later.
Do you know if BHK Signature amp sounds very same with Constellation amp?

I have not personally heard the Constellation amps, so cannot give you such a useful take on it.  But you might want to read some of the posts by "Dirk" at PS Audio's forum; he sold his Constellations for BHK gear and seems well pleased by the result.  I recall him speaking directly to the amp comparison and decision.