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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
ozzy's avatar
ozzy OP
7,466 posts
 
Well I think the best is the 2x connection. In a few days I will remove it and hear the amps solo to compare.

ozzy

gdnrbob
4,444 posts
 
Not to be a pain, but I wonder if you should leave the transformers set at a connection for a period of time.
I only say this because, when I adjusted my Vandy M5-HP crossovers, Johnny Rutan said they need to settle in for a few days before they exhibit their true character. This situation may be different, but I thought I would post my thoughts with the hope of having you make the best informed decision.
(BTW- I recall reading that Steve McCormack felt that the Zero Transformers made a significant difference even with his SS amps).
Bob
ozzy's avatar
ozzy OP
7,466 posts
 

gdnrbob,

Thank you for your post. Did you find the higher multiples better? What did you finally end up preferring?

I am pretty sure that the 2X is better with my amps and speakers. To me it was quickly apparent. The 3X setting increased the sense of more dynamics but the soundstage was not as open sounding. So, for now I will leave the 2X setting attached for maybe about a week .The only question is whether the system will sound better without it.

ozzy

ozzy's avatar
ozzy OP
7,466 posts
 

Oh, by the way. I like the Atmasphere M-60's so much that I did sell my Pass Labs X350.5 amp. It was a good sounding reliable amp but I won't miss the weight...

ozzy

charles1dad's avatar
charles1dad
10,250 posts
 
Ozzy,
When you described the Atma-Sphere as more natural sounding than the Pass Labs,  case closed IMO.  What's more desirable than improving that elusive characteristic? Natural = organic= realism. 
Charles 
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