Best Preamp - NO preamp... (?)

None of you have mentioned using a high quality passive pre.
Ami, you should consider this-  http://www.thebespokeaudiocompany.com/

Thanks for all your comments!

RE: shorter path / better parts with preamp - I doubt that is the case here. The passive I was using has a $400 P&G volume pot, and the volume control of the DS DAC is a digital one AFAIK, so it introduces no additional components in the signal path.

RE: a more expensive passive or some 'magic' signal processors, I am still to be convinced that adding anything in the signal path, no matter how good, can make things better.

RE: What is "better"? that is something I can't argue with. If you like the specific distortion or the coloration that a component introduces, then by all means, go for it. I am on the search for "Hi-Fi" - transparency and not coloration. I am of the opinion that if you need to add a preamp to make up for your speaker's deficiencies, you should be looking for better speakers.

RE: PS Audio BHK, I will ask Paul in the PS audio forum again. It will be interesting to hear his answer :-)

Have a wonderful weekend all!
 

infection,
I typed my response that the OP should try a TVC, and then deleted it.
I would highly recommend OP to try a TVC instead of using the DAC directly. It should not be a problem because he indicates that he has enough gain in the system.
The Bespoke is a pricey TVC. He can look for something on the lines of Promitheus Reference/Signature or Audio Music AMR-S.

+ 1 🖒, I am of the opinion that if you need to add a preamp to make up for your speaker's deficiencies, you should be looking for better speakers, by ami. Amen brother 😎

Dear ami,
Hi-Fi transparency can only be relevant to and very often at the price of tonal balance and dynamics. 

RE: What is "better"? that is something I can't argue with. If you like the specific distortion or the coloration that a component introduces, then by all means, go for it. I am on the search for "Hi-Fi" - transparency and not coloration. I am of the opinion that if you need to add a preamp to make up for your speaker's deficiencies, you should be looking for better speakers.

You can't be sure unless you compare the transparency of preamp vs. your source device directly to amp. The fact that you've chosen to use your source components directly instead of passive preamp speaks for itself that you like more active drive vs. anything else posters offered.
That's where simple math kills all the science behind.