Preamp Experiences with Atma-sphere Amps

I was using an ARC Ref1 with my M60MkIII's. After a discussion with Ralph I decided to try out an MP3. WOW! More transparency, detail, air, better sound stage and better defined bass that left me wondering why I needed a sub? You'll hear things in your music that you never knew were there before! I run 30' MIT 350 REF XLR between the MP3 and M60's. I sold my Ref1 along with some spare tubes and came out a $1000 on the plus side. An MP1 is in the long range future. The Atma-Sphere pre's will accept single ended inputs directly through the monitor inputs. My MSB Plat Plus DAC has a very high output and the MP3 handles it very well. If you decide on an MP3, try to find one that has the Regulator upgrade and V-Caps.

Mrderrick, or others, do you think the Atma pre works very well with the Atma amp, but might not be so strong with other amps? I real matter of synergy.

I've used a Conrad Johnson ACT2 with both the M-60s and the MA-1s - both of those the mk.III versions. Though the cabling was limited to single-ended RCA, with 3 meter ICs the CJ had a good grip on the amps. Its a preamp flush with virtues and they and all that wonderful OTL transparency came through in spades.

However, in my opinion - and not to put too fine a point on it - there is a really obvious synergistic choice for your situation and that is the MP-1. I cannot think of another sub-$20k preamp I'd pick ahead of it to drive the M-60s.

Tim

I tried my friends Atmasphere preamp (its there 15,000.00 one) with my VTL 450 monoblocks in balanced mode. I could not use it because it created a lot of hum. I am using a Audio Research Ref 2 mark 2 in balanced mode and it sounds wonderful. I have had several balanced preamps in my system with out hum. I think Atmasphere scheme on the balanced connector is not what most people in the industry uses. Ralph says otherwise, but the proof is in the pudding.

I've heard that that the atma-sphere is potentially hum sensitive depending on the tubes used in it. More sensitive to tube matching and selection.

I've been experimenting with a passive attenuator made by Music Reference and it sounds extremely good to me, I won't say how cheap it is. It is dead quiet, apparently dynamic, and plenty loud at the 3:00 position. I was suprised as the Atma amp is fairly insensitive, but my DAC is built like a preamp in terms of power reserves and the 2 meter CARDAS GR cables have very low capacitance (lowest on the market?). They say "no preamp" is better than any active, but I can't help thinking that the right active with the Atma-spheres would be better, but my passive is making me question the whole active stage argument, at least in my set up.

PLACETTE ACTIVE is the most transparent Preamp I've heard. If you like the rest of your system then you will really like the Placette Active. Guy Hamel is great. The price is actually cheap for what it is and it is sold factory direct, 30 day money back. I think everyone keeps the Placette! Used on Audiogon...not to often...why...guess! Peterh

I owned the Placette Active for a year. Yes a great preamp, but I preferred the Joule. We are in the realm of great gear and personal taste.

Well, I've decided the only way is to try an MP-3. If it can sound better than the Joule, that would be pretty impressive and I'll use the Joule with the Music Reference.

It arrived. :)

I'm using VH Audio Flavor 4, which I think are well made, but don't know how they might compare to others; but the system sounds very good with Atma/Atma combo. My final decision might be to upgrade to an MP-1; I love the M60s with my Merlins, and I have had a lot of amps; this just seems to be a great match.

Tvad,

Were the Tek Lines the cables you mentioned to me a few weeks back? I have tried Scott's cables before and found them to be good values. Is he on to something better with the new model you're using?

I use a Shunyata Helix Python on my MP-1, with that plugged into a Hydra V-Ray, and Shunyata Helix Taipans on MA-1 amps.

Significant improvement came with insertion of NOS 6SN7s in the line stage and NOS 12AT7s in the phono section of the MP-1. Likewise for NOS 6SN7s in the MA-1s. The Atma's are as sensitive (if not moreso) to tube selection as any gear I've owned and in my system swapping out some of the stock Chinese 6SN7s paid big dividends. (But neither PCs or tubes told just how good are the Atma-Sphere electronics until I added several Real Traps in my room.)

I take tube choices and power cords as largely a matter of personal taste. Mine include a Sylvania GTA or RCA GTB driver in the MA-1 along with Sylvania and Ken-Rad VT231s. Likewise in the MP-1, strategic placement of a single Ken-Rad or Raytheon VT231 in each channel of the line stage improved both the top-end air and sweetness of orchestral and other acoustic recordings, along with lower register tautness and timbre. Discussion of phono stage 12AT7s in the MP-1 probably warrant their own thread, but to drop a few names: Seimens, Sylvania and Mullard.

Pubul57 - how do you find the MP-3 compared with the Joule?

Tim

I can't tell if I'm hearing what I expect to be hearing, but it is the classic Joule/Atma divide one a bit warmer and more colorful, the other very transparent and incredible low level resolution - you can guess which is which./? I'm going to use the Joule with my Music Reference RM9SE for a slightly warmer and fleshier portrayl and the Atma/Atma for transparency and soundstage detail and air. Both great and slightly different flavors, heck if could choose one over the other. The Atma is newer for me me and I'm smitten with what an OTL can do, but really, hard to choose between them.

Oh just go ahead and get some Joule OTLs and go head to head with the Atma OTLs. That should be some fun.

Indeed, and I could get rid of my furnace in the winter time. Tony, I somehow suspect that I may very well have to try the faceoff someday.

What 6sn7s have you been succesful with in the MP-1. I'm using Early Sylvania 6sn7 gtb and they sound very good to me and quiet as far as I can tell. I'm using RCA Clear Tops for the 12au7 position (no phone stage).

Tim,

What position did you put the NOS tube in the MP-1 line stage?

Are you saying you only need to replace 1 tube on each channel?

Have you tried replacing all?

Here is some of what I've learned about tubes in the MP-1 Mark III:

As you stand facing the MP-1 with its cover off, the 6SN7 tube closest to the front panel in each channel has the most sonic influence on the linestage.

The three 12AT7s aligned in a row toward the left rear of each channel have the most influence on phono stage sonics.

The pair of 6SN7s in each channel that line up behind the tube closest to the front panel are particularly sensitive to noise and unmatched sections. As the MP-1 is a fully balanced design, closely matched sections *within* a tube are v. important for all its tubes.

Tube dampers really help on tubes you want to insure are the quietest. 'Herbies' are easily the best I've tried. In each channel I use 3 in the line stage and 3 in the phono section. At first you may think you've lost some sparkle, but give 'em time and you may find as I did that you've lost some distortion and gained a bit more timbral rightness and quiet.

With 10 6SN7s in the MP-1 and 5 in each channel of the MA-1s, I would have few spares if I used 20 tubes from my NOS stock to fill every socket. In my opinion the 6SN7s in the amps have more influence than all but the one in the MP-1 that I identified above, so I replace all in the MA-1s, and just the one in each channel of the MP-1. Today I'm using '40's black glass Ken-Rad VT-231s in the MP-1.

I appreciate Ralph's comments about the difficulty of finding decent 12AT7s for the phono stage, however it can be done. There I'm using late '60's Siemens-Halske triple mica E81CC tubes in the three critical spots with a Brimar filling out the fourth. I've also had good luck with the Sylvania Gold Brand 6201 sold by Kevin Deal, but the Siemens are really special.

YMMV.

Tim