Does a tube preamp warm up sound of SS amp?

The Bryston has a lowish input impedance on its XLR inputs, 20K Ohm per phase (it's common to give the sum of the phases in spec sheets), making it a poor match for some tube pre-amps with high output impedances.

The single-ended input of the Bryston is 50K Ohm, which will work with more pre-amps, but I'd still avoid very high source impedances (say 1000 Ohm and above).

If you want more flexibility, I'd look for an amp with a higher input impedance like 100K Ohm.

Thanks for both comments. Very helpful. The Audio Research ls5 mkii has Input impedance of 200K ohms balanced and Output impedance 400 ohms balanced Main (2), 20K ohms minimum load and 2000pF maximum capacitance. From what I think you're saying that ARC could work, right? Laurence

If bryton has low impedances the Manley shrimp is a good preamp for it because it has only 50 ohm output impedance.Good luck

I've used my BAT preamp with the 7BSST amps and had no problems. Bass was strong and deep.

Not all tube preamps will impart much if any warmth, it will depend on the preamp, the tube type and the general design and implementation.

A poster above suggested ARC, which I think are great and make some of the best preamps one can buy. However, that being said, the more current models that use the 6H30 super tubes are really anything but tubey sounding (in my opinion this is partially due to this specific tube). This is not a bad thing perse, but it should be noted that they will impart hardly any to no tubeyness in my experience (I own one FYI).

Another factor to consider is DC offset from the tubed preamp to the amp. At some point in either the amp or preamp this needs to be addressed.

CJ is more tubey, as will be some BATs (but not so much with the 6H30 tubes), Cary's are tubier as well.

My preference is the Aesthetix Calypso (owned it twice) and I still think it is one of the best tube preamps money can buy. It responds extremely well to tube rolling, which in essence gives you many different preamps - change the tubes and notably change the sound. It does not offset DC to the amp (per my conversation with Jim White).

I would put the Calypso on any list in considering tubed preamps (add 500-750 dollars for different tubes to play with). If this preamp is in your budget, I can recommend it very highly.

The Bryston, while being a good amp has a tendency to be a bit sterile in my opinion. Great company though. I would consider expanding my amp considerations. Doing so may yield more of what you are seeking via the tubed preamp approach in general, IMO.