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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?

jsqt
milpai's avatar
milpai
2,498 posts
 
@jsqt,
So I liked the sound without the O-rings for 2-3 days after which it started sounding fatiguing. I started looking into dampers that would not "constraint" my music. I came across Herbie's tube dampers. I was recommended the Ultrasonic SS tube dampers. I got them earlier this week and installed them right away. Well, I am pretty happy with how they got rid of the noise that I initially mistook as "open sound". The music and instruments sounds natural with these dampers. Love to get that musicality back in to my system.
hifiman5's avatar
hifiman5
1,836 posts
 
Herbie's products are well designed and carefully implemented with materials that are musically friendly.  I have Herbie's Tenderfeet under every component in my system. SO musical.  Their decouplers are great for speakers and subwoofers.  With them in place the rest of the house isn't vibrating with the deep bass of many favorites...also the vibes aren't stressing the Tenderfeet.  Tuning a system is that last, best step in realizing a system's full potential.
ebm
9,311 posts
 
NOS medical grade Amperex from Brent Jesse.Not cheap but wonderful sounding.
jsqt's avatar
jsqt OP
117 posts
 
@milpai that is interesting to hear, thanks for the follow up. I did remove the o rings on my Cifte’s for a couple of days and I could not really detect a difference to be honest. I do have mine on a slab of wood that is also sitting on 3 IsoAcoustic Oreas, so that combined with the terracones on the unit itself may make it less susceptible to noise? Or the Mazda Cifte could be less microphonic than the Gold Lions. I replaced the o rings and have left everything as-is.
A little over a month in and it is still sounding amazing with the MQ-88uSE. I did replace both power cords on the Rhumba Extreme and MQ-88uSE with Transparent High Performance PCs and I have noticed an improvement in detail, which I attribute to a lower noise floor overall in the system. 
I’m currently awaiting the Hugo TT2 to replace my Chord Qutest DAC; along with the M Scaler, I believe the Hugo TT2 will likely be end-game on the system. I couldn’t justify the expense of the DAVE and I have read rave reviews of the TT2/M Scaler combo (together surpassing the sound of the standalone $12K DAVE).
milpai's avatar
milpai
2,498 posts
 
Recently changed to a Psvane 12AU7 and love this tube over the Gold Lions. These are much more open, slightly less warm, but tons of details and superbly balanced. I got mine from Viva tubes in MA.
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