Backert Rhumba 1.3 OR Modwright LS 100 ?

@soix 

The Rhythm 1.3 has a fuller sound stage and an even more refined, realistic image. It really shows you why a good preamp is important and don’t get me wrong because the MZ preamp is a killer pre and same with the MZ2. Don’t forget the Rhythm is in the $10K range.

The LTA pre’s do respond well to tube rolling. I’m using all NOS tubes. Currently Ken Rad 6SN7 and NOS Brimar 12AU7.

@lancelock Thanks a lot for sharing your thoughts/experience, and I’ll definitely look into the tubes you mentioned. This is my first foray into tubes and I’m really looking forward to experimenting with various tubes so really helpful to hear LTA lends itself well to rolling, which I didn’t know before and very happy to hear. What changes did your NOS tubes produce versus the stock tubes?

I can’t see going wrong with either the Rhumba or MicroZOTL and have never heard anything negative written about either, which is pretty rare IME. The reason I went with the MZ2 was price and that it’s also an excellent headphone amp that I’m looking forward to hear driving my Hifiman Arya Stealth ‘phones so is a nice bonus in my particular use case. Thanks again for your valuable advice.

@soix There's quite a lot of useful info. in this thread.

https://forum.audiogon.com/discussions/tube-rolling-advice-for-the-backert-labs-rhumba-extreme

@twoleftears Thanks so much for that link — looks like a very valuable treasure trove of great info rooted in experience, which is the best kind of info.  I’ve bookmarked it and look forward to thoroughly reading through it and learning a ton.  

I was lucky enough to borrow a friend's rhumba extreme 1.3 for a week. Like the rhythm, it is a dual mono design. I tried it with schiit aegirs as monoblocks and the combo bested my pass integrated in dynamics and detail.