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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

ozzy
gdnrbob
4,507 posts
 
Ozzy, I don't have the Zero's. I only mentioned it because when I changed the crossover settings of the M5-HP, things sounded grainy/shrill. John Rutan said it was that the circuit needed to settle in for about 60 hours or so. Hence, I was wondering that if you changed the Zero settings, it, too, might need to 'burn in' in order for you to gauge the differences in sound quality. As I said, it may not be the same thing, but I thought I would mention it.
Glad to hear the Atma's living up to your wishes.
Bob
ozzy's avatar
ozzy OP
7,642 posts
 

Bob,

Thanks for that info.

ozzy 

ozzy's avatar
ozzy OP
7,642 posts
 

Well, I just removed the Zero’s from the M-60’s after about 10 days connected and once again used the amps solo. After listening to a few tracks I then replaced the Zero’s with the 2X connection.

In the end, I’ve got to admit the Zero’s are a needed complement to my DIY speakers. There is a wider soundstage along with much better dynamics.

So Ralph and others the Zero’s are keepers with my Atmasphere M-60's and my DIY speakers.

I also found that the Full Music 6SN7 tubes are the same as the Sophia tubes and at much lower price!

ozzy.

charles1dad's avatar
charles1dad
10,250 posts
 
Ozzy, 
Your results make sense,  the OTL reveals more of its  ultimate sonic performance driving the higher/easier impedance load. I bet your system sounds terrific,  Congratulations. 
Charles 
dragon_vibe
430 posts
 
Why not try 4 M60 Amps,

Wiring the Mid and Tweeter with 1 amp.

Wiring your lower Woofer with another M60.


I was just thininking of doing this to my classic audio loudspeakers.

I have the New Atma-Sphere Nirvana Amps and 2 Pairs of M60.

The Nirvana are being used for the large speakers.

The M60 is paired with a 2 way Studio Monitor.
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