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  3. 128359-41

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
7,502 posts
 

bigboltz,

Have you received your upgraded Atma-sphere's yet?

ozzy

bigboltz
55 posts
 
My MP-3 3.3 shipped on Friday. I'll have it Thursday.
My M60s are 3.1 and I'll send those in later this year. Gonna be a long 5 days!
ozzy's avatar
ozzy OP
7,502 posts
 

bigboltz,

That's Great!

Mine were also shipped but Ralph said the tubes in the unit are not so good but usable. So, I ordered some NOS from Russia and China but who knows when they will arrive?

According to the Fed Ex tracking (at this time), my amps are to arrive on Tuesday. I have a doctors appointment that day so I probably won't be able to use them until Wednesday.

ozzy

gdnrbob
4,452 posts
 
Not to sound rude, but why didn't you get some tubes from Ralph?
I only got into this recently, so I don't know much regarding tubes.
Are the Russian and Chinese tubes better? I have read about tube rolling and would like to learn more.
B
ozzy's avatar
ozzy OP
7,502 posts
 

gdnrbob,

Let’s just say it was about economics. I have other new tubes available (Tung-Sol and Sovtek) in addition to the Russian and Chinese tubes that I just ordered. So, I’m really not hurting for tubes.

But Ralph said to burn in the new tubes for about 72 hours in standby before using. I will be going crazy if I could not try out the amps until 3 days later after waiting this long! So I will use the tubes that will come with the M-60’s for the trial.

And, if the Atma-spheres become a keeper, I’ll burn in the tubes that I ordered.

I have some new driver tubes coming that I will have on Monday. They are vintage RCA 1950 (9 new).

The output tubes that I ordered from Russia are (16 new) Svetlana 1970. The Chinese tubes are (16 new) Shuguang 6NP5PJ.

However, if I don’t keep the Atma-spheres I will have a lot of tubes to sell...

P.S. As you can tell, I try to never do things half way. I remember years ago my wife wanted a gold fish bowl. I ended up with a 250 gallon saltwater reef tank!

ozzy


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