2. amps-preamps
  3. 184569-137818

Atma-Sphere MP3 or something else?

hey all

some quick background. I'm a headphones guy but use speaker amps/pre power combos for my Abyss TC (and previously Susvara). 

current gear is
Primaluna Evo 400 preamplifier
Nad M23 power amp
speaker cables to speaker/headphone adaptor box (with 0dB and -17dB attenuation switch); i use 0dB for the hard to drive headphones, and -17dB for more sensitive headphones like Utopia etc.

i have the Atma-Sphere MP3 on home demo for a couple of days/weeks. had some initial issues with a faulty 12AU7 tube, but Ralph @ Atma-Sphere was great in helping me trouble shoot the unit. Am still having some background mild hum/electrical noise, very faint and only audible between songs/during quiet music or passages. not a big issue; am guessing either the inherent gain or from the rather old 12AT7 tubes.  if i flick the switch on the speaker/headphones adaptor box to -17dB, then the background hum disappears.

from my own listening, i really like the MP3. i think it outclasses the Primaluna evo 400 especially in the low end and mids. top end is less clear/sparkly than the Primaluna, but overall it makes for a very warm, inviting, lush sound. music and staging, pretty much everything sounds grander and "bigger" with the Atma-Sphere.

i'm looking to get a new tube pre. the Atma-Sphere seems like a rather "old" model. i cant find any recent reviews or forum posts about it. anyone here still using the MP3 or have the newer MP3.3 variant? is the MP3.3 an audible improvement over the older models? is it still a "relevant" component? i was also looking at the Modwright LS36.5 but the local dealer doesnt have a unit on hand, so i cant demo it, and it'll be a blind buy.

 

128x128docroasty
atmasphere's avatar
atmasphere
11,625 posts
 

Your amplifier appears to have gain switches on the rear panel. If they are in the high gain position try a lower setting. That might sort your problem.

Make sure the amp and preamp are plugged into a wall outlet that is served by the same AC circuit. If they are on a different circuit, its possible to exceed what is known as the 'Common Mode Rejection Ratio' which can result in buzz/hum.

 

docroasty's avatar
docroasty OP
78 posts
 

i returned the demo unit to the dealer.
i actually really enjoyed the sound of this preamp, but sadly, i couldnt get rid of the background noise.. this despite switching out multiple tubes, cables, etc. I tried it with my speakers (Ascend Acoustics Sierra 2ex) and there was an audible whine from the ribbon tweeters. also moved the entire setup around the house to try different outlets but no luck.

am now considering the Cary SLP-05; emailed them to inquire, and Billy assures me it'll be silent. 

laaudionut
243 posts
 

Aric Audio Motherlode! Call Aric and discuss your gear and desired results. He will be a great resource for you and builds fantastic tube gear.

soix
8,776 posts
 

Take a hard look at Linear Tube Audio preamps.  I’d think the MZ3 or the MicroZOTL (depending on your needs) could be excellent candidates, and I think they even offer a trial period.  Best of luck.

https://www.lineartubeaudio.com/preamplifiers

docroasty's avatar
docroasty OP
78 posts
 

just to close the loop.. 

ended up ordering the slp-05. such a beautiful component indeed! it is dead silent with my gear (which was a massive relief). swapped out the stock tubes for a NOS Mullard GZ34 and a set of sylvania 6sn7 black plates and the sound is phenomenal. the low end feels like it will extend down forever. very holographic sounding with lovely width and front/back depth. the headphone out is unfortunately quite a bit of a disappointment.. but as a preamp, it is great!

cary slp-05cary

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