Atma Sphere Music Amplifier MA-2 Reference Edition

Powerful OTL amplifier, 2 x 220 watt monoblocks.

The MA-2 is noted for its superior performance on Sound Lab, Wilson Audio, JM Labs, Magnaplanar and Avalon loudspeakers. These are speakers that need an amplifier capable of serious power. An amplifier that can fully utilise the full bass frequency range of the speaker with the proper control and impact, while simultaneously retaining detail, delicacy, and speed. This is an unusual combination but this is what sets Atma-Sphere apart from the competition.

Balanced Differential Design
- Class-A 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
- Copper foil V-Cap Teflon coupling caps
- Standby switch for long output tube life
- Dual AC power circuits for each chassis
- 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-based triode tubes

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Output power
220 watts per channel into 4, 8 or 16 Ohm load before clipping

Impedance
Input Impedance: 100 KO single-ended,
200 KO balanced - selectable to 600 Ohm.
Output Impedance: 1.75 Ohm (open loop)

Input
Selectable up to 600 Ohm; 2.8 V sensitivity
RCA and XLR true balanced input

Tube complement
20 x 6AS7G output tube ( per channel )
6 x 6SN7 driver tube ( per channel )

Power Bandwidth
2Hz-150KHz within 1/2 dB

Frequency response
( 1 watt, open loop ) 20 Hz squarewave Tilt; unmeasureable, 1Hz-200KHz within 3 dB

Distortion
Total Harmonic Distortion ( THD ) typically 0.4% at full power.
Intermodulation ( IM ) distortion typically under .04% at full power
Phase shift less than 1 degree @ 20KHz

Dimensions
28 inch deep x 17 inch wide x 10 inch tall ( 71 x 43 x 25 cm ) per chassis

Weight
103 lbs ( 46.7 kg ), per chassis, without tubes