Anyone Here Have Atma-Sphere Amps?

Thanx twodolfins. I am certainly going to use them with ESLs. Good luck in finding your MA-1s!

I am using Atma Sphere M-60 MK III.2 & MP-1 with Quad ESL 2912. I am very happy with this setup. Many people use Atma Sphere with electrostatics. This is realy something special. Previously I have used Quad II eighty, EAR Yoshino V12 and some other amps with all kind of electrostatics. Atma Sphere is much much better in every possible way. I'm looking to upgrade to MA-1 so if any of Atma Sphere fans in Europe is selling one, please contact me.

Atmasphere, The lower the impedance the less efficient a speaker becomes. Transformerless SS amps respond to this by putting out more power and as long as their output sections can handle it and the power supplies can dish it out everyone is happy. Amps with transformers and your OTLs dish out constant power regardless of speaker impedance. So what happens when you try to drive say Wilsons which have notorious labile impedance curves? As the impedance falls and the speaker becomes more inefficient wouldn't these amps run out of grunt? I understand this is frequency dependent but I am not exactly sure how. Does the sensitivity of these speakers increase as the impedance falls?
Is a 200 watt OTL amp less powerful than a 200 watt direct coupled amp
or rather not as capable of the same high volume limits under this circumstance? Pardon me for being...an idiot but when it comes to these things I guess I am. I know what I want to hear and what has worked for me in the past. The next time I want to upgrade I would like to get it right the first time around as the stakes are much higher.

@mijostyn   Your Sound Labs don't behave with the 'lower the impedance the less efficient a speaker becomes' rule that is common with box speakers (although that description isn't entirely accurate...). IOW they maintain the same efficiency as their impedance goes up or down.


Regarding Wilsons, the national sales manager of Wilson ran Atma-Sphere amps for many years. I've heard our MA-1s with the Sashas and they seemed to work well together.

Regarding power- 200 watts is 200 watt regardless of what kind of amp makes the power.

I have been an Atma-Sphere customer for some time. I use the M60s in my system. They drive either Spendor 1/2e or Quad ESL 57 speakers. For speakers with difficult loads I use a set of Zero autoformers between the M60s and the speakers so that the amps sees a higher impedance. As Ralph has stated many times on these forums all amps behave better driving higher speaker loads.
Also, I would note that an Atma-Sphere OTL will put out less power into lower speaker impedance loads and more power into higher loads vs. a high current sold state amp that doubles power as the impedance is halved, but has reduced power as the load doubles. Ultimately I pay less attention to power these days. I'm more interested in how much distortion the amp is going to put out (it will put out less into higher loads) and if I can get my desired SPL level in my room with the amp and speaker of my choice. I find 30 - 60 watts is plenty for me.

Atmasphere, The lower the impedance the less efficient a speaker becomes. Transformerless SS amps respond to this by putting out more power and as long as their output sections can handle it and the power supplies can dish it out everyone is happy. Amps with transformers and your OTLs dish out constant power regardless of speaker impedance. So what happens when you try to drive say Wilsons which have notorious labile impedance curves? As the impedance falls and the speaker becomes more inefficient wouldn't these amps run out of grunt? I understand this is frequency dependent but I am not exactly sure how. Does the sensitivity of these speakers increase as the impedance falls?
Is a 200 watt OTL amp less powerful than a 200 watt direct coupled amp
or rather not as capable of the same high volume limits under this circumstance? Pardon me for being...an idiot but when it comes to these things I guess I am. I know what I want to hear and what has worked for me in the past. The next time I want to upgrade I would like to get it right the first time around as the stakes are much higher.
   

Atmasphere, if I order a set of MA 3s can I get them in red :)

I was referring to the 60s and the MA1s.

Ralph,

Thank you so much for your response. I did not know that. I’ll go back to your website and read the review. 

@joeinid Horns aren't a problem including AvantGardes- a review is on our S-30 page. We have an adapter we use to reduce the gain of the amplifier for use with really high efficiency loudspeakers (it replaces at tube in the voltage amplifier). It also reduces the noise floor. 

I would love to hear the S-30 on my Avantgarde Duo XD. I bet it's wonderful. My speakers are 18 ohms at 107 db. I just don't know if there would be any audible noise from my speakers without a signal. It would be fun, I'm sure. 

Ralph. That color was a deep crimson and very beautiful. You should keep offering it as a standard color! IMO.

Given that and parts and you can see why they cost so much. Also Mr Karsten insists they are just fine driving loads down to 4 ohms.
Now we can ask Mr Karsten, Ralph, why would an employee's set of M60s be red??

@mijostyn  Actually MA-3s can handle loads much lower than 4 ohms! The MA-1 and MA-2 can do 4 ohms as well.

That employee just wanted red...

Now we can ask Mr Karsten, Ralph, why would an employee's set of M60s be red??

I would speculate the answer to be "because he can."  Just take the standard M60 case work to a painter / powder coater  and return it to the shop for assembly. 

jsautter the MA3s are $147,000. That is no joke. But, it takes 3 months to build the entire very large 4 piece set. I do not know how many people are involved in the labor but I would bet it is at least 4 if not more. Given that and parts and you can see why they cost so much. Also Mr Karsten insists they are just fine driving loads down to 4 ohms. 
Now we can ask Mr Karsten, Ralph, why would an employee's set of M60s be red??

Driving high impedance speakers the Atma OTLs are among the few best amps I have ever heard or owned. The other amps on this list were at least 5 times the price of the Atma-spheres.

Thanks, Ralph. I saw them at Audio Perfection in Minneapolis Minn. Probably not far from you.

If it was red, it was an employee's set of M-60 power amps.

I looked at a Atma-Sphere amp a few years ago. What I do remember was it looked of very good build quality and was red in color. What I don't remember, was it an integrated or a power amp? What was it's output? And lastly, what was its retail price? Could someone help my failing memory?  ;-)

Thanx pstores. It certainly seems hard to find someone with a negative comment. I have not had a tube amp since my Stereo 70 days. Plenty of tube preamps including the first Conrad Johnson which I tore out of its chassis mounted it in a new box minus most of the switches, wired it with silver wire and added a Sowter MC transfomer internally. No boredom in my life. It was ugly as hell. 

I have the MA-1 silvers and M60’s as well as a hot rodded UV-1. And can say Bob  is spot on.... Never had an issue with the tubes. Also he customer support is one of the absolute best in the industry. His amps and preamps are truly magnificent in my humble opinion. 

Thank you Bob. Yes, I am talking to Mr Karsten and he is very helpful and enthusiastic. I love the workmanship and point to point wiring. Internally they are works of art. He told me it takes three months to wire a set of MA 3s

I own the MA-1's and MP-3, both are great pieces of equipment.
Also, Ralph Karsten is one of the best manufacturers in the business. There is another discussion regarding Atmasphere and Ralph here on Audiogon.
As far as tubes go, I haven't had any issues with my amp for almost 3 years. (Though the preamp needed a new tube recently). The nice thing is that I can call Atma and get someone to help troubleshoot.
Bob