Backert Labs Rhumba preamp

I am thinking of going to an active line stage for sometime now. I have a separate thread for that and people have suggested some good choices. The reason for this thread if that, while I have all along said that  don't want tubes in the system, a few have convinced me that I should try tubes in the system, especially with ProAcs.
With that said, I researched a few tube preamps, that have XLR out and the Backert Labs Rhumba is the one that has only 2 tubes, which makes me comfortable to "deal in tubes".

I would like to hear from Backert Labs Rhumba owners who moved from Solid State preamplification to this preamp. What are the differences you heard? Any improvements?

I read a review on the Stevehoffman forum and the user mentioned that there is a "hum" in this preamp. This bothers me and hence I decided to check on this forum, if anyone has experienced this with the Rhumba in their system. One poster on this forum also confirmed the "hiss":

So I was wondering, if there are any users who have recently purchased this preamp and what is their experience with the hum/hiss issue.

BTW, I blame Ralph of Atma-Sphere, Almarg  and my dealer for making me consider tube amps :-) Can't believe I am creating this thread.

@bdp24 ,Thank You for letting me know about EAR. I will research a bit and find more information. Yes, who does not know Tim de Paravicino. I do have a few Water Lily SACDs.
as a Backert Labs Rhythm user myself, i can highly recommend their fantastic linestage. i upgraded from Rhumba to Rhythm . From experience, the simpler the design the less problem you encounter from it, and the more easier to solve if any. It also doesn't necessarily mean a balanced connection or a fully balanced design circuit (i.e MP-3) will give you lower noise or have any advantage over single ended design. Fully balance design circuit will also susceptible to hum problems too.
 i'm being a BL user for 2.5 years and quite familiar with their pre. so if you need any advice about Backert Labs pre, feel free to ask .
@philipwu   How would you characterize the sonic difference between the two Backert line stages?
Thank You @audiothesis and @philipwu 

@philipwu ,
Do you have the Rhythm 1.1 or the 1.2? Like hifiman5, I would like to hear about the differences between your Rhythm and the Rhumba that you previously owned. Now was that Rhumba 1.1 or 1.2?