Atma-Sphere M60 or David Berning ZH270?


Hi, I need some helps to decide which one of these two amplifiers to go with my 14ohm Coincident Super Eclipse (SE).

The Atma-Sphere seems a perfect match for the SE at least in impedance matching and at 14ohm, may get more power than 60 watts. The ZH270 may get less than 70 watts @14ohm. However, I have the following concerns for the M60:

1. 8 6AS7 output tubes per side generates a lot of heat and it does not have cage protection. This is quite a problem if you have young children at home like me. The ZH270 has tubes internal (like a Tube preamplifier) and thus safer for young children.

2. 16 6AS7, though last long time, can be more expensive than ZH270's 4 6JN6 if I try to replace them.

Pro for ZH270 can run without a preamp and is auto-biasing.

On the other hand, ZH270 is more expensive ($4995) than M60 MKII.2 ($4250) (current still have a few left).

As far as the most important factor: sound? I have no idea at all. I have not heard either one anywhere. I have owned ASL Hurricane for over a year and like the sound very much but disappointed for the constant re-biasing and QC problem.

Does any one have Reliability problem with either one?

My listening room is 13Wx8Hx26L and I listen almost only classical music from solo violin, piano, to chamber music to 20 century's big symphony orchestra works (Mahler, Strauss, Stravinsky, etc.).

Thanks for the helps.
laoyuap
Hi, Tom:

Thanks for the response. I may have already made the decision but just want to hear opinions from product owners and have final check in case I miss something. I haven't heard either one before and spending close to $5k makes me a bit nervous.

Thanks again.
Laoyuap,
Hopefully this will help...
I own a Berning ZH270, and have heard both amps. Both are share many similar attributes in their sound, but for my ears, the Berning is playing in a different league than the M60s. Your observations about both are spot on. As you state, the Bernings relative lack of heat, small chasis size,auto-biasing, remarkably long-lasting tubes and volume control are all good things. However, the reason I bought the Berning is simply that its sonic performance is amazing, especially at its price point. This and it's resale value, should you ever have to sell, are the best reasons to go with a Berning. Allan Bhagan and David give excellent support with upgrades and service questions. Repairs are rare from what I've heard.
Both of these amps come from fine companies. Ralph Karsten is a great guy, and I have many friends(regular A-goners) who happily listen thru Atmas.
I've heard the M60 with Coincidents, and it wasn't the best combo compared to some modified Frieds with the M60. Contact member Trelja for more details, this is his gear.
Cheers, Spencer
I've never heard either of these amps with co-incidents, but I am one of the few that found the Berning a little more analytical than the M-60s (2.3) with merlins. But if you have young kids, and the amps will be where they can reach them, then that may be the deciding factor. As you would expect, the Atmas run quite hot. Ouch. Sonically, you won't regret either one.
First of all the disclaimer: I am a dealer for Atma-Sphere. I once owned and do think highly of the Berning amp, though I'm not a dealer for them.

The reason I did not become a dealer for Berning is that I preferred the M-60 in a side-by-side comparison in my system, driving original Quad ESL's (the "57's") and some home-brew dynamic speakers. I have heard the Berning and M-60 driving Merlin VSMs, and once again preferred the M-60. I find it to be more lively and have a richer texture, drawing me more deeply into the music.

That being said, the Berning has a lot going for it. It sounds great, is very lightweight, cool-running, and can be used without a preamp. The variable output impedance control is a wonderful feature that I'd like to see on more amplifiers. Pound for pound, the little Berning is more than likely the best amplifier made.

The Atma-Sphere M-60 does require periodic rebiasing, but that takes about one minute and the only tool required is a screwdriver. You also need to observe the turn-on switch sequence, so it's a bit less user-friendly if non-audiophile family members will be operating it. While the M-60 can accept single-ended inputs, it sounds best with balanced inputs (though in the side-by-side comparison I mention above I used single-ended inputs because at the time I didn't have a balanced preamp). Note that you can also run the Atma-Spheres with less than the full tube complement, reducing the heat output and still sounding excellent (and maybe even better?) with a high-impedance speaker like your Coincidents.

I have the impression that the Berning is comfortable with a wide range of loudspeaker impedances (the variable output impedance helps here), but the Atma-Sphere M-60's don't like speakers with impedances below 8 ohms unless the impedance curve is smooth and the efficiency fairly high.

The Berning is a very fine-sounding amplifier and offers an excellent collection of qualities at a very reasonable price. Sonically it's probably among the top 10% of amps in its general power and price range. Given appropriate loudspeaker matching (such as your Super Eclipses), the Atma-Sphere M-60 is the most musically engaging amp that I have heard in its general power and price range (the 27-watt, 845-tubed deHavilland SET is also excellent, though I don't sell it). At that which they do well - which is lifelike timbres and textures, engaging liveliness, and rich inner harmonic detail - the Atma-Spheres are truly superb.

But remember I'm a dealer, fin on my back, toothy grin and outstretched hand...

Duke
Hi, Spencer,

You opinion really help. It gives me more solid affirmation for my thinking. Regarding the combination of Coincedent + M60, I thought Israel voices his speakers on Atma-Sphere especially M60 Mk2, maybe I remembered wrong...

Thanks again.