Which DAC as a preamp?

Cary 600.  Friggin awesome as a stand-alone with a 3 volt outputDoes it all and sounds fantastic.   Based on AKM 4497 Dac set. 28 lb beast. All sorts of digital ins and outs. Roon , Mqa, integrated SD card reader. It is sweet  and you will never tire of listening to it 

just never worked for me without a pre. that said the mytek manhattan has an analog pre and is a very good dac. 

@shadorne , @transience, I too expected my very mellow balanced tube preamp to tame the highly analytical M6S for a perfect match. On SOME recordings -- notably those originally analog mastered -- it works splendidly despite subsequent remastering. (Example: Keith Olson's 1975 "Fleetwood Mac" eponymous album remastered in 2017). But on more recent, digitally mastered material with substantial high-frequency content, the M6S's 768 upsampling screams like a banshee, cackling right past the tubes when coupled with RCA-terminal coax. Have not yet tried using USB or optical (M6S has no AES input), but if those don't tame it, I've got serious trouble. 

Any hints? Maybe I will start a new thread if a different coupling doesn't help. 

@hicksmore 

RCA coax is intended for digital signals. I suggest to try the M6S RCA analog output with simple analog RCA cables.

I've not heard the DACs listed by the OP. I've found the Sonnet Morpheus to be excellent driving my ATC SCM100ASLT active speakers.