PREAMPLIFIER UPGRADE QUESTION

+6 on the Backert Labs Rhumba.

I have owned the Rhumba 1.3 since 2018. Roll some NOS tubes and your will be amazed by the sound quality. NOS Mazdas are what I sincerely recommend.

Damn! I had to edit my post just to correct the "number". 5 people above me al;ready recommended it.

I just realized the newest Rhumba 1.4 is fully balanced and at $5k with a 14-day trial period that’d be where I’d go first. 

@soix, Rhumba 1.3 has 1 fully balanced XLR input and output, while 1.4 has 2 each.

@kjl1065 - I recommend the Linear Tube Audio Microzotl preamp with the upgrade.  It’s below your budget and sounds so good it’s the one component I wouldn’t consider parting with. When I put it in it was the single biggest upgrade I’ve made. 

I think the Rogue is fully balanced, is it not?

As an interim step, if not already, you could upgrade the tubes in the RP-1. I put a set of Mullards in from Andy’s tube services and have really enjoyed them. Enjoy those while you continue research on high grade pre

Also you might try the PS Audio BHK Pre.  That has 12AU7 valved input stage. And you can possibly trial that unit and they give you a decent amount for the Rogue.  Although you proly do better selling RP-1 on your own as people snap those up pretty quickly.