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
Not that I know of. The tube testers I've seen don't make that distinction. If in doubt treat the tube as a GT.

atmasphere,

Can you share your comparison? Ralph, I know you are the owner of Atmasphere but I would really like to hear your opinion. And Is there an on line comparison?

I am only asking because I really do love the M-60’s amps. But, the Prima Luna gets more press coverage and is only single ended.

I think it would be very interesting for a head to head comparison sound quality wise. I did hear the Prima Luna at a Dealers showroom a few years back and I was not impressed. At the time I was using Pass Labs amp and the Eggleston Andra 2 speakers and the dealer was using Sonus Faber speakers with the Prima Luna.

My bet would be on the Atmasphere stomping the Prima Luna.

ozzy

OK: you asked. A lot has to do with the speaker of course, but the feedback we have from customers is that if the two amps are on a speaker that is friendly to both that essentially it is as you surmise.

But we get that a lot and not just with comparison to the Primaluna. That such is so is not surprising on two fronts; the most obvious being that obviously the positive comments are coming from customers that set the amps up right. The other is the overall design features of the amp; M-60 has full power to 2 Hz and can play bass quite well, owing to only one stage of gain and a direct-coupled output. With so little to go wrong its obviously very fast and more transparent without brightness. Triode operation. Fully differential. And so on (no single feature, but the combination of all of them makes for what the amp is). manufacturer caveat: we make the M-60 amplifier.