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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
charles1dad's avatar
charles1dad
6,996 posts
 
Hi Ozzy,
TJ Full Music is the parent Chinese manufacturer. Sophia supposedly is selected from the "better" grade tubes made by TJ Full Music. Sophia doesn’t have their own tube making capacity/facilities. 
Charles 
ozzy's avatar
ozzy OP
3,650 posts
 

almarg,

I have noticed a very low level hum when I place my ear up to the speakers with no music playing. But, it is minimal and I overall prefer the sound quality over that minor annoyance. Perhaps if they are installed in a preamp it may cause more problems downstream.

charles1dad,

How does Sophia get there brand on the tubes if they select the best ones? I think they just purchase a lot of the tubes from TJ and have them branded "Sophia" then they grade them A-C. I think the grade A ones are used in the USA market and sold direct from within the USA.

ozzy

charles1dad's avatar
charles1dad
6,996 posts
 
Agree that’s there’s some method of selecting/rejecting tubes from the original vendor TJ Full Music. I was just making the point that they’re re-branded tubes under the Sophia name.
Charles
gdnrbob
2,421 posts
 
As this is my first Tube Amp and Preamp, I have no idea who sells these, nor who is a good source. So, where do you guys get these tubes?
Bob
charles1dad's avatar
charles1dad
6,996 posts
 
Sophia Electric. com, their own site.

TJ Full Music tubes
1  DIY HIFI Supply
2  tubes-sale.com
3  Grant Fidelity. com
Charles 
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