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 , make sure that 6SN7 that sits in the front by itself is a -GTA or -GTB. That particular position has more voltage on it and the older GT style tubes will have a shorter life in that position. FWIW the Russian and Chinese tubes marked 'GT' seem to be OK in that position.

atmasphere,

I know many that I have were listed as GTB but the writing on the glass tube is gone.

Any way to physically check it ?

ozzy

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.