Preamp Upgrade

@sidvee
+1 on the Rhumba 1.3 preamp. Good to know that you were able to compare it to much more expensive preamp and it can compete. I changed the tubes to Gold Lions and the sound is even more natural. The bass became even more thunderous. And yes, Andy responds promptly and is very helpful. 

I picked up a Rhumba 1.3 recently. Really love what the Rhumba is doing in my system.  The bass is well extended and there is a lush midrange coupled with smooth extended highs along with a wide and deep soundstage.  I have been through many pre-amps in the past decade ranging upto $8k (most recent was a Lamm ll2.1 deluxe) and I can confidently say that, in my system at-least the Rhumba 1.3 favorably competes with all of them.  Lastly the support I got from Andy at Backert was phenomenal.  Easily the best customer service that I have experienced in the recent past.  I highly recommend Backert to any one planning to get a tube preamplifier.

+1 on Backert. 

I replaced a dual mono TVC in my system for better Dynamics and drive. But never expected the new preamp to beat the TVC for transparency. I highly recommend the Backert Labs Rhumba 1.3  for you. You will have to add the phono separately though.

You should look into Don Sachs SP14 preamp.  You could get his pre with all the upgrades for a lot less than $3500. 

I used to have that same preamp and with your budget you could certainly improve on it. Browsing the listings a few things that jumped out at me.
https://www.audiogon.com/listings/lis9d9ic-first-sound-presence-deluxe-4-0-with-paramount-upgrade-tu...
If you can accommodate  three chassis this is a serious dual mono preamp and a really great deal for $3495.
https://www.audiogon.com/listings/tube-doshi-audio-preamplifier-system-2017-04-01-preamplifiers-9812...
I have not heard any of his gear but Nick Doshi is certainly getting tons of great reviews and show mentions and this preamp looks like a nice deal.
And of course you could always upgrade to a new Herron.......
https://www.audiogon.com/listings/lis9af8j-herron-audio-vtsp-3a-tube
There are certainly some nice choices within your budget have fun choosing and I hope you find a preamp you love!