Best Preamp - NO preamp... (?)

Hi Ami.
Since I have the same DS dac you have, perhaps I can shed some light.
First I have to give a dealer alert, since I sell the Ps line.
while the DS happens to have an extremely transparent volume, and it does sound great in my system, a top preamp will enhance your sound and enjoyment.
If one has a less than stellar pre amp, then yes the DS direct might in fact be preferable. But running the DS at less than full output (or with the -20db attenuator) is a compromise.
The preamp I’m running is a $15k all tube two box unit, but there is a stellar option at almost 1/3’rd the price.
Paul at Ps has stated that their new BHK preamp sounds much better than the DS direct.
In fact Bascom king has stated that it is the best preamp he has ever designed. And his other designs are super expensive. His hybrid design actually varies the level of tube gain as well as attenuate, so it’s a novel and very transparent approach.
While I haven’t gotten one in our system yet, having the BHK 300 Mono amps in our system, I can assure you that Bascom teamed up with Ps’s value driven aesthetic means these electronics, while not cheap, represent edge of the art sound at real world prices.
If you’re serious about building a world class system, (and you have an world class source in the DS- and one that keeps getting better with each new OS release) you need an active preamp (not a passive unit)
Also going balanced will help and means that even cheap cables can work extremely well.  
If you're ever in the NYC Area I can demo the DS direct vs. Through a great preamp.  Triode picture sound.  

Just to clarify.   I have heard it explained that The volume control in the Ps audio DS (I'm a dealer) is digital up until 50 - from 50 to 100 it is analog.  as Robert Deuch found it sounds fantastic and close in sound to the Cat preamp.   Well as good as the DS is - the reports from Paul at ps audio is that the BHK preamp is significantly better in all respects.   he's a straight shooter and these days won't release a product that doesn't live up to his expectations.   He spent years developing a hypex based amp with custom front end, and scraped it because there were better out there. 
audio doesn't always make sense.  One would think less parts means better sound but it doesn't always.  
Bascom king who measures electronics for a magazine once tested a ss amp from a DAC manufacturer that measured much lower in distortion than any other - but it didn't sound good.  
Paul McGowan was against using a tube input and in fact planned to offer a solid state input and and tube as well (ss on a tube socket) but once he heard the tube input he had to throw out his preconceptions and just build his new amp with tube input only.