I have heard both and for my ears, prefer the Atma-spheres. It would make for a very interesting comparison.
Since the M60's were also sold as kits, I would be very careful if you buy one. Make sure you find out the history of the amplifier and what modifications were done. You can contact Ralph and I am sure he can let you know the details of almost any amp he has sold.
I have heard some small improvements using NOS tubes in the Atma-sphere's, but I do not think it is truly necessary for your comparison.
Let us know how it turns out if you can pull off the comparison. If you cannot find anyone to do it, I have a couple of friends with the Berning's and also someone locally with the M-60.
What speakers do you have? If I have to do the comparison, I would like to try and have speakers like yours to use for it.
Me too :) Whoever is in the Chicagoland area and has the M-60's can perhaps bring them on over and we'll we could make an afternoon of it :)
I would automatically go with the Atma-sphere M-60's, but I suspect they are going to be "space heaters". Correct?
The heat issue is what attracts me to take a look at the Berning. My current amp puts out a lot of heat and I assume the Atma-spheres would put out even more.
Assuming that the Berning and the M-60's were relatively close in sound, the heat factor becomes more important.
I will again mention that the Berning Seigfried is the amp to compare with these others. The ZH270 is a push/pull amp with feedback. The Seigfried is single-ended triode with no feedback. I know it is only 12 watts, but it will drive most reasonable speakers quite well.
I just got the Siegfried amp with the WE300B tubes.
I'd say its doubtful that a 60 betters the 270 significantly in terms of sonic integrity across the board. There is a switch to adjust feedback of the 270 with a "Low" option which is in my opinion the way to go, it is wonderful.
I'm not sure who's ears I trust, Jtinn's or his "couple of friends."
The Atmasphere M-60's were what I was going to buy at first instead of the Berning 270 and I chose the 270 for its obvious advantages. I took a chance with the 270 not having heard the 60 or 270 at the time and feel I chose wisely, I also can use whatever speakers I want with the 270, a person is more limited with the 60's.
I have to agree with TWL. The Berning Siegfried, after 12+ yrs in this hobby, has blown me away to a place I thought I was too jaded to experience anymore. (I'm using the 300b model, w/ Avantgarde Duos). I haven't heard Atma Sphere gear, or even the 270, for that matter. All I wonder is why the Siegfried remains such a secret. It's a technical and sonic masterpiece. It has all the finesse and intimacy of any tubed gear I've ever heard, with none of the coloration or euphony, and much higher musical resolution. And the bass slam, authority and control of a SS rig. How insane is that?
I wish I could use the Siegfried on Soundlabs :)
I'll tell you what Davidz, you ship your Siegfried to me and I'll ship my zh270 to you and then we'll both have a frame of reference of how one compares to the other. And of course we'll post our results here. I KNOW Twl and Chris are interested in the comparison, whata ya say? I think I could live with 10 watts of Siegfried for a week or two.
Will, Chris, et. al., If you guys are like me, you need to hear things yourself to judge (plus it's more fun! to actually play with the equipment) rather than rely on what others say. Having said that, there was a thread over on the Asylum a while back where comparisons between the Seigfried and the 270 were made. If I remember right, they were judged to be pretty close, given the significant design differences. Do a search for 'seigfried' in SET asylum, I think. No substitute for hearing the real thing, of course.....
BTW, The Atma-spheres were much clearer sounding but the Bernings had a tiny bit better sense of dimensionality .
Its quite hard to believe the Atmaspheres are much cleaner sounding than a Berning, Oneprof is right on however, I simply must hear them for myself. The Berning is one of the clearest sounding amps I have heard, period. Anyone is entitled to their opinion, in this case I just plain need to listen to both amps side by side to judge for myself.
Will, I am jealus that your speakers can operate with a Siegfried, really jealus actually :) For this very reason, I should think about aquireing more efficient speakers at some point that can be driven by an SET.
Maybe I can scrounge up some speakers to use with the Siefried and you guys can send it to my place when you are done comparing :) I'd even be willing to let the person use my 270 in the mean time :) I am really only kidding of course but I do wish I could hear a Siegfried at some point, preferably soon :)