Upgrade preamp?

Bryston 7B3’s and looking to potentially upgrade my preamp from a Schiit Freya + to .......?

Your 7B3’s have an input impedance of just 7.5kohm!!!, this is not very good for a good "impedance match" for any passive and most tube preamps .
Search for preamps that have low output impedance, good SS ones will be the best ones to get low output impedance.

The tube preamp that jjss49 mentions is a good one as it has a solid state output stage, that gives it a low output impedance, one of the very few tube pre’s that do.
Conrad Johnson:
"preamplifier outputs through a high-current MOSFET buffer, which achieves a very low output impedance, making the ET5 extremely flexible in the choice"


Cheers George

the goal would be increased clarity/resolution and sound stage.

There are a couple Bryston BP26es for sale on eBay for around $3k that will give you these characteristics in spades.  Truly like “straight wire with gain” type sound.  Best way of luck. 

Nothing wrong with Maggie 1.7s, but if I had your system and looking to spend 5K on a preamp I’d look at speakers first. 1.7s are fine but they have their limitations. Yes I am very familiar with the 1.7s.

I don’t own, but have heard, a system with Bryston preamp and amps, and I thought there was great synergy. I’d suggest (as @soix did) that you at least listen to a Bryston preamp. (I have a 4B3 but use a different preamp because my room necessitates DSP bass correction.)

AVM has a tube output stage in its PA 5.2 and an output impedance of 100ohms.  This lists for $5500 and could be a very interesting unit at the high end of your budget.  This is an extremely smooth sounding and enjoyable preamp.  For jazz, it would be brilliant.  If you like a tube sound but need SS performance, this could be an amazing option for you.  
There is a new AVM PA 30.3 coming out in the next two months or so and have an output impedance of 50ohms.  This thing is feature packed!  Obviously I haven’t heard this yet but I have yet to hear anything from AVM I don’t love.  
The Musical Fidelity M8 Pre has an output impedance of 47ohms and is just under $5k list.  MF is known to be very Musical and a strong value since it is made in Taiwan.  
At a lower price, the M6s Pre also has an output impedance of 47ohms and at a list of $1900 represents an amazing value.  
These  should work with you Bryston amps well.  These are neutral to slightly warm in sound profile. 
If you would like to discuss further, want the manuals or need additional info, feel free to PM me.