Preamps


I'm not unhappy with the Jeff Rowland Corus preamp,  but I don't know what I don't know. I'm currently looking for a solid state preamp with HT bypass to compare to my Jeff Rowland Corus preamp. I would like suggestions below $15K new list price to listen to. I have a Jeff Rowland 625 S2 amplifier, Antipodes DS GT music server and Chord Dave DAC. 
ricred1
Ayre KX-R
a superb SS preamp from a now departed genius
... and a fanatical implementation of volume control

Definitely consider and audition the GamuT D3i. We used it last year at AXPONA and will again this year, along with their D200i mono amps. Incredible combined natural sound and resolution. It is available with a phono stage. PF and other reviews available online.
Note: the GamuT's USA distributor also distributes our product and is a personal friend. I have no commercial interest in/with the GamuT products.Good luck with your search.
When I first received the Dave I tried it straight into the amp and preferred music with the preamp inserted.

Yes, I can see that. But first you have to make sure you weren't "bit stripping" if the volume on the Dave was below 75% of full you could have been losing "bits" (lowering the resolution from 16bit to 14 to 12 ect the lower you go below 75%).
  
If it wasn't "bit stripping"  then yes going direct can sound absolutely stunning with unmatched transparency and dynamics with the good to best recordings, but then almost unlistenable with the bad recordings, it gives you everything warts and all and pulls no punches.

A preamp will be a a bit of an equalizer pulling back a little on the good/best recordings, and making the bad one a bit easier to listen to.
It all depends if your prepared to cull some of those bad recordings for the sake of hearing the good ones at their very best. 

Cheers George  
Thanks to everyone for responding. I will look into a couple of the recommendations. I actually need a preamp with HT bypass, so going direct isn't an option anymore.
Another nod for Ayre. I also recommend T+A P3000HV. 

There is a demo T+A on Agon, 

https://www.audiogon.com/listings/lis8hd59-t-a-elektroakustik-p3000hv-available-in-titanium-and-silv...

And this is hot off the press for you to consider, 

https://www.stereophile.com/content/emm-labs-dv2-da-processor

Should you choose to look into a Tube pre, ARC Ref6 should be on your list. I believe it will be a killer pre for your 625 S2 amp.