Atma-Sphere M-60 Mk II.3 Tube Mono Power Amplifier

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  • Regular price $4,650.00

Atma-Sphere M-60 Mk II.3 Tube Mono Power Amplifier


Do you appreciate the magic of a really good tube amp? Do you listen in a big (and dare I say air-conditioned) room? Do you make an honest living for crappy pay? Then you, my friend, should drive like hell to the nearest Atma-Sphere dealer you can find and clap your ears on a pair of these.

For years now the M-60 in its various forms has been the subject of the Soundstage!.com Hall of Fame Award, The Absolute Sound Golden Ear Award and Editor's Choice, with numerous accolades in the press and on the web. 


  • Exclusively triode-based, vacuum tube circuitry 
  • Pure class-A operation 
  • Patented Atma-Sphere direct-coupled (OTL) output stage 
  • Balanced Differential Design
  • Mono chassis construction 
  • Easily monostrapped for greatly increased power 
  • Standby switch for long output tube life 
  • Only one stage of gain throughout 
  • XLR and RCA input connectors 
  • Proprietary, precision grade components used throughout 
  • Low-noise "star" ground circuit 
  • Fully hand wired electronics; no circuit boards! 
  • Classic open chassis construction with Wrinkletex finish 
  • Two-year general coverage warranty, one year on output tubes


Power: 60 W / channel into 8 ohm load, 45 W / ch. into 4 ohm, 80 W / ch. into 16 ohm
Power bandwidth: 2 Hz to 75 kHz (+- 0.5 dB) 
Frequency response (1 W): 1 Hz - 200 kHz within 1/2 dB 
Intermodulation distortion: 0.05 % @ full power 
THD: typically under 1 % with proper setup
20Hz square wave tilt: Unmeasurable 
Phase shift: less than 1 degree @ 20 kHz 
Power supply storage: 140 J / chassis 
Output section risetime: 600 V / micro-second 
Output impedance: ~4.1 ohm 
Feedback: 1 dB 
Power consumption: 300 W / chassis 
Tube complement: 8 x 6AS7 / channel and 4 x 6SN7
Weight: 30 lb
Dimensions (WDH): 17 x 13 x 8.5"