Upgrading pre amp advice.

I’ll chime in that the Don Sachs preamp is a brilliant piece.  It’s a refined version of the Tubes4HiFi SP14, which in turn is based on John Broskie’s "Aikido" preamp, which incorporates a noise-cancellation circuit that is eminently simply but quite brilliant.  It employs the most linear preamp tube in all of audio, the 6SN7, and takes it to new heights.  It features a quiet background and a natural distortion-free sound that is perpetually listenable.  My own preamp is a modified version of this and it never fails to be open and musical.  He’s stopped making them but if you can find a used one I don’t think you’ll be disappointed.  It puts out tons of music, regardless of your tastes.  Alternatively, you can purchase a new version of the SP14 from Tubes4HiFi.  IMO it’s one of the great bargains in high-end audio.

@vhond 

The main  differences I heard in my setup between the Ayre K-5xe- mp and the Musical Fidelity Ms8pre was the size of the sound stage the Ayre was more confined but no less enjoyable but the Ms8pre threw a sound stage that extended itself beyond the speakers whilst maintaining instrument placement a solidity, it wa s also more refined with a better sense of timber and hormonic structure . It also excelled at low level listening. 

Unity Gain Designs are extremely transparent and not producing an overbearing upper frequency in any way at all.

A Valve Pre' will have quite noticeable tonality is compared to a Unity Gain. 

A AVC or TVC will also have a noticeable tonality when compared to a Unity Gain, but will be lesser than the Valve influence on Tonality. 

This is my experience of being a Valve Amp user of more than 30 years and a Slagle AVC owner for 10 years. 

I have no issues with Tonal Influences from recognisable Rich Tonal  Influence, through to perceivable Transparency. In recent times, I go to the Transparent Influence, more than a influence from a hint of Rich Tone. 

@vthokie83 ​​@dogearedaudio : I took a look at the website of Tubes4HiFi (really interesting, but none them where balanced)

@jdub39 : thanks for this additional info

Someone experiences/reflections on the SPL Selecter??

@vhond 

I am not familiar with your Bryston (or much of the rest of your rig for that matter), so I make these suggestions with caveat...

Might be worth looking at a used Zesto. I have several clients that have these and love them. The one I’ve heard was excellent. There was one I was considering on US Audiomart not long ago within your budget, I think. If I remember correctly it had balanced in’s and out’s.

Might also be worth looking at a VAC Standard Preamp. There was one with a phono stage on Reverb for $2K. Not balanced I don’t think but a very nice pre-amp for the price. You can sometimes see the VAC Renaissance pre-amps pop up that are still relatively close to your budget.

Good luck.