Tube Rolling Advice for the Backert Labs Rhumba Extreme?

Tomorrow I have a Backert Labs Rhumba Extreme 1.2 being delivered, which has been upgraded by Backert to 1.3 specs. It will be driving the Luxman MQ-88uSE and the front end is a Qutest with M Scaler (Innuos Zen MK III server/streamer). Speakers are La Scala IIs, placed about 15' apart in the corners at a 45º angle. Soundstage is excellent and expansive with remarkable placement of instruments across the sound field.

If all goes well it will be replacing my L-509X, which is currently only being used as a preamp for the MQ-88uSE, so it’s being underserved in my system and will need to find a better home.

I am interested in any advice about tube rolling with the Backert Labs pres. With the Chord digital front end, I am getting a very layered, dimensional, detailed sound and thanks to the Qutest filters I’m able to adjust filters to best match the amplification. The MQ-88uSE has a gorgeous, full, warm sound and right now the 509X’s solid state pre is giving a nice sharp, detailed, and dynamic profile to sharpen up the tube sound a bit.

I don’t want a syrupy or bloated tube sound, more airy and detailed on the top with holographic imaging with solid heft on the bottom end. I’ve replaced the preamp tube in my Cronos Magnum II with a Cifte and was really happy with the impact on the sound.

The Backert comes stock with new Mullards, which I expect may have a slightly warmer sound than what I’m chasing.

Any advice?

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As this thread is about tube makes and models that do especially well in Backert preamps, I'm going to reiterate my recommendation of the--admittedly rare and costly--Amperex 7316.  This is what Brent Jessee has to say about them.

Simply an amazing tube. Amazing both because it sounds so incredibly good, and amazing how rare it is today. The 7316 was made by Amperex in Holland, I have never seen this in any other brand, nor have I seen it made by Amperex North America. It is a medical grade/aircraft equipment grade super low noise tube, not sold to the general public. It is Amperex's answer to the ECC802S produced by Telefunken, and the 10M series made by Mullard. Most have the Bugle Boy on the label, although I have seen plain Amperex labels, and OEM labels such as Beckman Instruments. The 1950s vintage with the long plates and D-getters are to die for. They are among the best sounding and rarest 12AU7 around today. Don't miss the 1960s halo getter version of this tube, as well. They sound nearly as good as the D-getters and are usually half the price. Very few dealers ever have the 7316 of either type in stock, well worth seeking out and worth the higher price. We try to keep a few of each type in stock, but it is not easy. Better buy them when you can find them!

Unfortunately, it's all true.

@milpai I’ve just started my tube rolling journey with my Rhumba Extreme 1.3, and my first change was to the Psvane Art Series. Holy mother of tubes! After only 9 hours on them, they are already a giant leap ahead of the stock Mullard tubes. Thanks for rec! After the first hour, they excelled in all areas except bass extension and the vocals were still somewhat thin. But now, the sub-bass region is gaining some weight and overall, in the Extreme 1.3, they make my system sound really incredible. I’m looking forward to the other tubes that are en route to me, but i think these will be hard to beat... I suspect even by the NOS stuff.

Edit:  By the way, I'm not using any damper rings on the tubes.  The Backert pre is on Townshend isolation pods and the cables going to it are also isolated from vibrations.

I was talking to a long-time audiophile on the phone a couple days ago and he said that tubes don't make that much of a difference in sound compared to fuses.  This is just two 12AU7 tubes on a linestage, and the difference is very profound.  I'm more doubtful than ever about his claim


Good to know that the Psvane ART tubes worked for you. Hope you enjoy them for a long time. I have no experience with tubes and hence in no position to comment.

I will endorse the latest iteration of the Psvane tubes as the best new-production 12AU7's to use in the Backert.  In my experience they are only surpassed by the NOS Amperexes that I mentioned above, which are very hard to find and very expensive when you do.