Hi-End Audio Tube Amplifiers, 2 x 60 Watts, OTL monoblocs, Mk 3.3
For years now the M-60 in its various forms has been the subject of the Soundstage! Hall of Fame Award, The Absolute Sound Golden Ear Award and Editor's Choice, with numerous accolades in the press and on the web.
The M-60 Mk. 3.3 continues that tradition with classic styling and its award-winning state-of-the-art performance. The M-60 gives you the features and precision performance of our larger models in a beautiful, 60-watt package. The amp operates class A and is unconditionally stable with reliability proven over many years.
The power tubes are inexpensive, readily available and do not require any matching. Sporting a classic, open-chassis construction, the M-60 Mk. 3.3 sets the bar for hi-end amplifier performance.
FEATURES
- Balanced Differential Design®
- Class-A2 operation
- Patented Circlotronic® direct-coupled (OTL) output stage
- Dual-mono chassis construction
- Automatic bias - no adjustment needed
- Built in VU meter for tube and output monitoring
- Easily monostrapped for greatly increased power
- Standby switch for long output tube life
- Uses only one gain stage for supreme clarity of sound
- Proprietary precision components used throughout
- Low-noise "star" grounding topology
- Fully hand-wired point-to-point electronics - no circuit boards!
- Stable with all input and load conditions
- Uses octal base triode vacuum tubes
- Classic open chassis construction with Wrinkletex™ finish
- Three-year general coverage warranty, one year warranty on output tubes
Audio Traveller
Part Time Audiophile, Josh Emmons, Axpona 2015
The Absolute Sound
Sue Kraft, April 2009
Scot Markwell, April 2002
AudioReview.com
Ocean Aletheia, November 2018
Various, user submitted
Dagogo.com
Jack Roberts, December 2010
Enjoy the Music
Wayne Donnelly, March 2003
Follow up, Wayne Donnelly, with ZERO autoformers, July 2003
Robb Report 2023 Audio Awards
Best Two-Channel Vacuum Tube One-Brand Separates: Atma-Sphere M-60 Amplifier and MP-3 Preamplifier
Glass Audio
Charles Hansen, 1998
Listener
Art Dudley, 1996
Positive Feedback
Harvey Rosenberg, April 1997
Soundstage!
Tim Aucremann, June 2006
Ken Micallef, August 2001
Todd Warnke, October 1999
UltraAudio.com
Vade Forrester, January 2011
An insight into how we build our award-winning OTL amplifier
The Atma-Sphere M-60 amplifier is handmade with the highest quality components. We offer to our customers the possibility to further customize our products, according to their needs.
Output power
60 watts per channel into 8 Ω load
45 watts per channel into 4 Ω load
80 watts per channel into 16 Ω load
Impedance
Input Impedance: 100 KΩ single-ended, 200 KΩ balanced Output Impedance: ~4.1 Ω
Input
3 V sensitivity ( for full output )
RCA and XLR true balanced input
Tube complement
8 x 6AS7G output tube ( per channel )
4 x 6SN7 driver tube ( per channel )
Gain
20dB (for 8 Ω)
Power Bandwidth
2Hz-75KHz within ½ dB
Frequency response
(1 watt, open loop) 20 Hz squarewave Tilt, unmeasureable
1Hz-200KHz within 3 dB
Power supply storage
140 Joules ( per channel )
Distortion
Total Harmonic Distortion (THD) typically 1% at full power.
Intermodulation (IM) distortion typically under .04% at full power.
Phase shift less than 1° @ 20KHz
Output section risetime
600 V/µs
Feedback
1 dB
Power consumption
300 watts ( per channel )
Dimensions & Weight
13" deep x 17" wide x 8" tall (33 x 43 x 20 cm) per chassis
30 lbs (13.6 kg), per chassis, without tubes
Warranty
Three year general coverage
One year for output tubes
Power Supply Boost
V-Cap Copper Foil Teflon® coupling caps
Caddock® resistor package
Meter Panel finish options
Black
Brushed anodized silver
Brushed anodized gold
Jumper plugs for high efficiency speakers - Replaces tube in the voltage amplifier section of Atma-Sphere
power amplifiers, thus reducing gain for high efficiency speakers. Recommended when efficiency of speaker is over 100dB.
Cables
Balanced Interconnects
Balanced phono cables
1 meter, DIN to XLR or RCA with ground post to XLR
Atma Sphere
1742 Selby Avenue
St. Paul, MN 55104
USA
Email:
ralph@atma-sphere.com
Tel : +1 651-690-2246