Backert Rhumba 1.3 vs Herron Reference?

I've not, but can certainly attest to the quality of the Herron 360 preamp; I bought both this line stage preamp and a phono preamp from Keith about 4 years ago, and have had no desire to upgrade from them. I hope you find somebody who has heard both of them you're asking about... 

Thanks @larsman 

I recently bought the Herron, as my first entry into a higher level preamp. I like it but have nothing to compare it to, so was thinking of the Rhumba to compare and get a baseline for my liking. 

Never had the opportunity to audition a Herron preamp but I do own a Backert Labs Rhythm 1.3 . Please contact them for a loaner before you make a decision. Andy is a great guy. I find that my Backert has a control over bass notes that makes a sonic difference in my system. Please check my avatar.

Something else to keep in mind is that Backert Labs would still seem to be going, whereas Keith Herron has retired.... 

I have had Heron and CJ preamps for many, many years. The Heron is one of the best. It would cost more to get a better sounding preamp. Larsman is right. Keith has retired. But my Heron amp and preamp are close to 15 years old and just fine. A CJ ET7S2 would be a close replacement. You may want to simply keep it and consider a different upgrade path. 

Follow up. NJcardave is also right. If the bug is biting, go for the home trial. Ypu cannot go wrong either preamp, but let your ears decide. But do not rush.