2. amps-preamps
  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

Showing 10 responses by bigboltz

bigboltz
55 posts
 
ozzy, 

So you're the one keepin Ralph and his crew busy!  I'm waiting on an MP-3 that is being updated to 3.3.  The wait is torture!  I finally found a unit on the used market, but it was a very early model. I did get lucky, as the seller was in Minnesota, and kindly offered to drop it off. Its been a few weeks now, but I'm sure it will be worth the wait.  It will be replacing an AtmaSphere UV-1, and feeding a pair of M-60 3.1 driving Vandersteen Quatros.  I cant wait.  Though now I'm probably gonna want to send in the amps for updates... 
bigboltz
55 posts
 
ozzy

I heard from Ralph today ( ok, he emailed back cuz I bug him once a week) and he said he's done the initial testing and expects to have it in the system next week.  Maybe my pre and your amps will end up testing together!    Anyway, I can't say enough about the level of customer service AtmaSphere has given me.
bigboltz
55 posts
 
gdnrbob

The M60s drive my Quatros with no problem.  I rarely get past 12 oclock on the volume and its more than enough.  Vandies have a rep of liking alot of power, but are a fairly easy load. 8ohms pretty much strait across. Plus, with the powered subs and hi-pass, no issues.  I thought about the volume control, but I'm already stretching my budget. What do you think of it?  

And I'm really curious about the phono stage. I'm hoping its great, I sold my Allnic 1201 to make this possible.  Tell me I wont be too disappointed!
bigboltz
55 posts
 
ozzy

The Quatros require -3db at 100hz.  Ralph is actually building that into one of the outputs for me, so i wont need to use the external crossover(m5hp) that goes between the pre and power amps. Vandersteen has a rather unique way of hi-passing their speakers, whether it be the Quatro and up or model 3 and down used with seperate subs
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!
bigboltz
55 posts
 
gdnrbob,

I'll get my MP-3 this week. I was wondering if yours has the phono stage and if so, what do you think? What others have you had for comparison?
bigboltz
55 posts
 
Ozzy

Take out the amber and red lamps and replace them with 12v version. They run alot dimmer. Also, standby is just the amber lights on.  
bigboltz
55 posts
 
Yeah ozzy, whaddaya think?!
bigboltz
55 posts
 
Well Ive had my MP3 3.3 for 24 hrs or so.   I'm sure I would have to take out a 2nd on the house or sell a kidney to do any better.  Its early but clearly a big step up for me.  The staging is super cool. Each instrument pinpointed in its own space. Depth is remarkable.  

This will surprise no one, but Ralph has been wonderful in his support and has shown great patience with all of my questions and requests. 

Thanks to you and your team, atmasphere!
bigboltz
55 posts
 
Ozzy

Ive had my M60s for about 7 months. I bought them used and they came with a ton of the Chinese power tubes. The seller didnt indicate which ones were good or not. So it took and evening of swapping ( and a box of fuses) to get them up and running and holding the DC offset.  Since then, I've had 2 tubes fail. Each took out the fuse by the power cord.  Otherwise, they have been rock solid. I play them at least a few hours each evening and sometimes all weekend long.  Dont get discouraged.   I plan on re-tubing with the Russian variety soon.  

Soundwise, I swapped them out with a pair of Quicksilver monos( which are great amps in their own right) and it was quickly apparent how special they really are.  The Quickies seemed slow and veiled by comparison.



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