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Preamp suggestions for Atma-Sphere Class D Monoblocks

As I impatiently await the arrival of my Atma-Sphere class-d monos, I am writing to solicit opinions from experienced members on this site. Balanced inputs and outputs as well as the ability to connect a subwoofer are important. Headphone amp would be nice but not critical. Ditto for built-in phono. These are some of the tube and solid state units I am considering (not necessarily exhaustive):

  1. Atma-Sphere MP-3 mk3.3
  2. Cary SLP-05 (ultimate edition, if I can find a pristine used pair at a good price)
  3. Modwright LS-100
  4. PrimaLuna EVO 400
  5. Supratek - Champagne or 6SN7 Cabernet - I have no idea what the difference between these two are and the website is not helpful at all
  6. Anthem STR
  7. Benchmark LA-4/HPA-4
  8. Bryston BR-20 (or one of their purely analog variants - BP-19?) - I am hesitant to bundle streaming and dac into a preamp
  9. NAD M66
  10. ?

I will initially use the Bel Canto DAC2.8 as a dac and preamp with an Auralic Aries G1.1 as the streamer. My speakers are Totem Acoustic Forest Signatures, sub is a REL s/510 that I seldom use. I am unsure whether I can use the speaker level connections with the A-S monos (my current Bel Canto Ref510S class d amp has a chassis grounding screw to which I connect the REL’s ground wire).

Philosophically speaking, I have owned a wide range of equipment over the years - everything from "measurements above all" type gear (a full Benchmark stack), a few tube pieces (PrimaLuna, Tavish Design, Rogue), Class A amplification (Pass Labs XA-30.8) and a completely active Genelec 8351b based system. I seem to be slowly but surely gravitating towards subjectively great sounding gear, regardless of how they measure - the Totems are a case in point. However, I don’t want to find that I have moved too far in any one direction. At the end of the day, I value realism and emotional connection more than the ability to deconstruct the music but I don’t want to listen to a sloppy system that homogenizes everything. I’m sure this is all clear as mud! It is however, a reflection of where I am at the end of 28 years of being on this hamster wheel. All thoughts and suggestions welcome. Thanks in advance.

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osiris369
25 posts
 

As a general fan of the BluOS platform, I'd lean toward the NAD M66 (assuming streaming will be a routine). 

But I also say proceed with caution and do a lot of research before hand. NAD failed spectacularly with the initial release of the C658 streaming preamp. It has most of the same bells & whistles as the M66. But the integration of DIRAC did not go so well. I'm not sure if it was a software problem or hardware problem. Looking at recent reviews it still has not been 100% resolved. The annoying part is that NAD & Bluesound both blamed the other and took no responsibility to make things right with the customer.

 

So again - proceed with caution. Only purchase from a retailer that has stellar customer service, and doesn't hassle you if you want to make a return.  

 

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dhungana
36 posts
 

Audio Mirror Wave. Vlad is very easy to work with and he just added sub out. This may suit your needs.

https://www.stereotimes.com/post/audio-mirror-wave-tube-preamplifier-by-terry-london/

https://forum.audiogon.com/discussions/audio-mirror-wave-tube-based-line-stage-is-one-of-stereotimes-2023-most

sc53
719 posts
 

A bit off-topic but I thought it important to mention that running a single REL sub with monoblocks and, separately, class D amps takes special care. I could not successfully configure a single REL sub with my BAT monoblocks. Had to use 2 subs. I was using the Speakon connector. 

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srama OP
65 posts
 

So many great suggestions, thank you all! 

As @acman3, @armstrod and others have mentioned, the A-S MP-3 is a recurring theme, which is understandable, given the amp it will be paired with. It is definitely on my short list, as long as remote capability is available. Does anyone have comments on their ability to cast a holographic soundstage, realism and tonality?

Backert Labs gets a lot of love here on AudioGon forums as well. Interestingly, I met Bob Backert many years ago (at that time he lived about 25 minutes from where I am, in PA) when the seller of a Musical Fidelity preamp I bought on AudioGon recommended him to fix a problem with it. He impressed me as highly knowledgeable and as a modest, soft-spoken gentleman. I have no doubt that his products are outstanding. However, all except for the "base" Rhumba 1.4 are outside what I want to spend at the moment. Which, of course, may be all I need.

The LTA microzotl sounds great on paper, but probably not the best match for the A-S monos as it does not have balanced outputs. 

@osiris369, I am a fan of the BluOS platform as well and have owned many of their offerings - M10, C389(?) and was initially considering a comprehensive solution such as the M66 or the Bryston BR-20. I have decided ultimately to keep streaming and dac functions separate (as they change the most often) and focus on purchasing a pure analog preamp which is capable of sprinkling a little "magic" into the system.

@rmdmoore, thanks for the +1 for the Modwright LS100 - it is very appealing, especially at used prices. If I understand correctly, however, it is not a true balanced design so I don't know whether I will be losing something with the A-S monos?

As it stands, the A-S MP-3 and the Spatial Raven are tied at the top. It's great to have multiple options! Thanks again to everyone for your much valued opinions. 

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jallan
300 posts
 

I own a CarySLP 05 with ultimate upgrade. Bought it used a few years ago in pristine condition for $4300. It has a decent headphone amp. I’ve had great fun tube rolling and my current setup uses Raytheon VT231’s in the gain stages and CBS Hytron 5692’s in the buffer positions. I have a variety of VT231 and 5692 tubes to play with and it is fun to optimize certain characteristics (for example, Ken-Rad VT-231’s seem to have the most solid bass while still being creamy in the highs, while Sylvania seem to have a bit of sparkle in the highs, with this being heard from VT-231’s to NOS 6SN7 GTB’s from the 1960’s. 
 

Tube rolling doesn’t have to be expensive- I really like the NOS Sylvania GTB’s from the 1960’s that I bought at $35 matched each from Brent Jessee, enjoying them far more New Sensor Electroharmonix tubes.

 

 I have really enjoyed this preamp. Tremendous imaging with well-resolved holographic instrument placement, very quiet with black backgrounds, tremendous sense of dynamics and inner detail. Make sure to use a high quality rectifier tube!

 

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