Preamp Upgrade

I have a Herron VTSP-1/166. Sounds great. Looking for better. I don't know a lot about preamps. I had been using a passive for years until I bought and Herron VTPH and found that they work best often with Herron preamps. Now I've found another phono stage I love and I'm thinking about upgrading the pre. Is there something incredibly simple (I'm vinyl only) that is an upgrade to what I have? Or have preamps not become better for the buck in the last 7 years and it's going to cost $3500 to improve on what I have?
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.
If you can accommodate  three chassis this is a serious dual mono preamp and a really great deal for $3495.
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.......
There are certainly some nice choices within your budget have fun choosing and I hope you find a preamp you love!
You should look into Don Sachs SP14 preamp.  You could get his pre with all the upgrades for a lot less than $3500. 
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.
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 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.