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Amps Atma-Sphere M-60 Mono blocks OTL design

I just purchased a used OTL Atma-Sphere M-60 mono blocks that I have sent to Atma-Sphere to be upgraded to the current model 3.3 and I also added the option of a higher quality power supply and V caps.

I have sold my old trusted Eggleston Andra 2’s speakers and have built some monitors using Aurum Cantus ribbons (102db) and Aurum Cantus midwoofers (90db) that are both rated as 8 ohm nominal. I have a DEQX Premate and will be crossing over to (2) JL Audio F-113 subs at 80hz.

Currently I am using a solid state high power stereo amp (Pass Labs) that I used with the Andra 2’s.

The Atma-Sphere M-60 is rated at 60 watts class A and is said to work better with higher impedance loads.

It will probably be a few weeks until I get the M-60 and was hoping someone could provide opinions of what to expect.

I listen to late 60 early 70’s classic rock music mostly. Sometimes loud.

ozzy

128x128ozzy
gdnrbob
4,410 posts
 
Funny you should post this thread.
After 3 months of waiting. I finally got my Atma-sphere MA-1 2.2 (upgraded to 3.3) and MP-3 put into place and running.
My significant other kept hounding me-'This better be worth it'.

Well, after 30 seconds, even he noticed the improvement.
Everything was clear and defined. Drums, horns, piano, you name it, just sounded right- Alive!
I always thought my system sounded good. Now it sounds great.
I have to email Ralph and tell him, but your post got my attention and I had to reply.
Those Egglestons are really nice. A quick google shows they dip down to 4 ohm. The M 60 should be up to the task, but I would ask Ralph if you should get some Zero's.
Bob
ozzy's avatar
ozzy OP
7,206 posts
 

sksos1,gdnrbob,

Thank you so much for your comments. So with my set up these Amps should work fairly well?

My thinking is the Atma-Sphere M-60's will not have to power anything below 80hz and with my present 90db+ speakers they should work really well?

Did either of you have the V cap and power supply upgrade?

bassdude
456 posts
 
Yes... 

Unless your speakers are very efficient (e.g. say 94db+) you will most likely want to get a set of Autoformers from Anti-cables to boost the impedence of your speakers to reduce the load on the M60's.

http://anticables.com/autoformers
sksos1
387 posts
 
ozzy that's the only way we have ever ordered any Atmasphere gear, with both the V-cap and Power Boost upgrade.

As for will it work well with the speakers you describe? Ralph would be the best to answer that.

(Dealer disclaimer)
ozzy's avatar
ozzy OP
7,206 posts
 

bassdude,

Thanks for the info.

You really think I will need the Zero's if the M-60's will only need to power 80hz and above?

sksos1,

Can you comment on the V caps as to how many caps are involved, and what exactly is the Power boost upgrade?

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