Preamps

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. 

@georgehifi said: ...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,
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Precisely my experience with a wonderful passive I auditioned that was much cleaner than the DAC volume control.  There were just too many recording where I really didn't want the band in the room because the mastering sucked.  A real conundrum.  Can I handle the truth? I'm back to that loosy-goosy search for a "sweet sounding" linestage.

It's my understanding that ARC preamps have issues when using a subwoofer and I have a JL Audio F112 v2 sub.

I think step #1 is to identify what you think the weaknesses of the Rowland are, and /or what you want further improved.
Honestly with out that its a crap shoot/
G