Anyone Here Have Atma-Sphere Amps?


I find these amps very intriguing and was wondering what people with real experience think. I have read all the reviews
which are generally excellent except for some reason Stereophile has not reviewed them as far as I can tell.
The main question I have is how often if ever do you blow a tube and how long are your tubes lasting. Do you have any quibbles. I would love to find an MA 3 owner as that is one ballsy amplifier. There is no such thing as overkill when it comes to power amps.
mijostyn

Showing 6 responses by mijostyn

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
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. 
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??
Atmasphere, if I order a set of MA 3s can I get them in red :)
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.
   
Thanx twodolfins. I am certainly going to use them with ESLs. Good luck in finding your MA-1s!