2. amps-preamps
  3. 190562-2906

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.

Ag insider logo xs@2xsrama
avanti1960
1,451 posts
 

@srama

The atma sphere monos have unusually low gain for an amplifier (22db)  compared to most that typically have 29 or 30 db gain.  

much like my Pass Labs XA 25 amp that has 20 db gain, they really match well with preamps that have higher than typical gain.  
My Cary SLP 05 has that with a 24 db low noise gain stage with balanced connections.  It matched amazingly well with the Pass amp and should do just as well with the atma spheres.  The SLP 05 does create a smooth holographic atmo sphere of its own in addition to be excitingly dynamic.  Get the 05. 

Ag insider logo xs@2x
srama OP
65 posts
 

@avanti1960, thanks for your comment. I did notice the low gain on the A-S class D (compared to the 27 dB on my Bel Canto Ref501S). I can see how the high gain in the Cary can help offset the low gain in the A-S. I would think, however, that the MP-3 would drive the class Ds effectively given they are both from the same designer?

That said, the SLP-05 is hugely attractive - both aesthetically as well as based on the specs. I just don't want to spend close to $8K at its current sale price for the ultimate version, and I'm not crazy about purchasing tube gear that is several years old.

 

avanti1960
1,451 posts
 

@srama, of course but to me more gain does improve the energy and dynamics. no need for the ultimate upgrade, just get some nos sylvania down the road.

The SLP 05 is now on sale at cary direct for $5997 !

 

https://carydirect.com/shop-now/preamplifiers/slp-05.html 

 

atmasphere's avatar
atmasphere
11,740 posts
 

One thing I noticed in comparison to the other two amps under discussion is the significantly larger number of tubes in the MP-3 - is this because it is the only truly balanced preamplifier is this set? Does this have any implications on maintenance, require more frequent changes to an entire complement of tubes, etc.?

@srama The tube complement depends on whether the phono section is included or not- the line stage uses four tubes. There are more tubes because its fully differential. In practice the 6SN7s of the line stage hold up quite well- we rarely replace them in warranty (which is a year on tubes). The phono section works with LOMC.

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srama OP
65 posts
 

In practice the 6SN7s of the line stage hold up quite well- we rarely replace them in warranty (which is a year on tubes).

@atmasphere, Thank you, that is good to know.

To reference @avanti1960’s post above, I assume there will be sufficient gain between the MP-3 and the Class D to power my speakers (Totem Acoustic Forest Signatures)? I certainly don't want to end up with restrained dynamics or the sense that the music is somehow being strangled.

 

 

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