Atma-Sphere MA-1 amps

08-04-08: Jb0194
Amp-loudspeaker matching is no less important with Atma amps as with any other amps.

An understatement.

In fact, amp/speaker matching is more important with Atma-Sphere amplifiers than with many other amplifiers.

IMO.

Is it possible for you to characterise your experience with the Atma amps before, during (break-in) and after when the sound finally settled?

 
Thank you Tom.
 
I found the amps and preamp more similar than different across break-in. Out of the box there was plenty of resolution, but the sound was a little tight and closed-in. Relatively speaking, tonality had a wee bit of a greyish cast. During break-in, which I counted roughly at 120 hrs for the preamp, and a little more for the MA-1s, music gradually became relaxed and seemed to flow with a more natural pace. Tonal colors made something of a transformation towards the end of the break-in period - they really blossomed - all of which was rather startling. That final leap came over a few days for the preamp, and, say, over a weeks time for the MA-1.

The subsequent addition of the V-Caps to the MP-1 took things back a step before going forward two. Highs and the mid-bass got a tad edgy and a touch of the greyish tonality returned. Over roughly 6 weeks, things smoothed out and the tonal colors deepened. Sonic memory is difficult, but I'm confident that tonality eventually improved beyond where things had got to prior to the V-Cap upgrade.

Fwiw, I find both amps and preamp sound their best after being on for 1-2 hours - the hotter their tubes the better.

Tim
 

Hello Detlof,

Thanks for the kind and respectful response. It's nice to be able to discuss the audible differences we discern in components, agree or disagree, still have fun and learn from each others experience. BTW ... Hilary Hahn smokes!!!

I haven't heard it myself yet, but from what I know the Sound Lab/Atma-Sphere combo is becoming classic. I'm sure your system must sound fantastic.

Detlof, a live recording of a piano with a close up perspective may give you the best chance of experiencing what I heard. Something like a small jazz ensemble, recorded in a intimate night club played back at a "live" playback level. In particular, listen to the attack of piano notes about 2 and a half octaves above middle C and up. What I heard (at least) was a unnatural sharpness, glare, zippity-zing if you will on the attack of those notes. The sustained note also sounded too thin and glassy to me. I started to hear this treble abbreviation on a variety of instruments and recordings I'm familiar with.

Another thing I try to listen for is the density of timbre/texture as a sustained note gets louder. Take for instance, a tenor sax player who plays one sustained note, he starts the note out at a medium volume and increases it to a loud volume. The note doesn't just get louder, the density of the texture also becomes more vibrant and more harmonically complex, it fills with ebullient energy. To me, some other amps convey this sensation with more conviction.

Tim, I want to thank you also for sharing your experience. Who knows? Maybe it was still a break-in issue with the V-cap after all. Much of what you described about the V-cap break-in mirrors my experience. I think too many variables are at play here to know for certain.

Enjoy,
Tom

Hello Tom,

HH sure does. I am glad you agree. Thank you for your additional information. I'll go an researching. I suspect, my Wavac phono pre kindly glosses over the shortcomings you mentioned, without being euphonic though, as was the case with the old Jadis gear I once owned, because today I had the occasion to try out a Boulder 2008 phono pre amp and heard exactly what you did, fiddling wildly with the VTA of my cart with no avail. But then it may be the cable between cart and Boulder not yet broken in. We'll see, but you may very well have a point, because the Sound Labs should be no less revealing than the Avalons from what I have heard. We'll see, respective hear, after all this is a work in progress.
Cheers,
Detlof

A question for NOS tube users - Howoftendoyou change 6SN7s? I have a set coming this week. I'm just wondering if I'm starting a very expensive and unsustainable habit.