Upgrading pre amp advice.

vhond

I'd have to agree with what some others have said here, I think you really need to spend a bit more than your budget to get real improvement. One of the most important pieces of equipment I ever bought was my Aric Audio Motherlode XL, it made improvement in almost every category of sound I can think of.

Supratek preamplifiers are some of the best affordable preamps I have tried, I can recommend the 6SN7 Cabernet $3,500/$4,000 and the Cabernet DHT $4,000/$4,500 (6SN7 and 300B)......the 2 prices are for the standard finish versus the chrome finish, the chrome is worth the upgrade IMO; they are stunning preamps. If you can find them used, they are an absolute steal.....but only last a few hours or days on used sites.

The Aric Audio Super 6SN7 is a great preamp as well (though bested by their big brothers the Motherlode II and Motherlode XL). They are $4,675 new, or around $3,500 used, but they literally last for hours on the used market.

Here is a used Don Sachs Model 2 6SN7 preamp for $2,000. I have never heard one, but Don's reputation is impeccable. It will not last long https://www.ebay.com/itm/336354312156

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.