Atma-Sphere - MA-1 Mk. 3.3


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AS - MA1
In stock


MA-1 Mk.3.3

Monoblock Music Amplifier


Features :

Recipient of The Absolute Sound's prestigious "Golden Ear Award" in 2000, the MA-1 has enjoyed an enviable reputation. Now the Mk. 3.3 series builds on the advances of our decades-proven technology. An improved output section and enhanced driver circuit contribute to superior low-level detail, smoother sound, wider bandwidth and AC power immunity. The new, rugged, non-magnetic chassis features classic looks with superior layout. Setup of the amplifier is simple with it's automatic tube biasing system. The controls and switches are ergonomic without sacrificing performance.

The MA-1 is extraordinary in every way. Not only is normal operation easy on the vacuum tubes, the effect of a tube failure on the unit is entirely inconsequential. Despite its extreme performance, the MA-1 is known for remarkable ease of setup, ease of operation, and day-to-day consistency. You will not be dissapointed.

Featuring our new custom wire, V-Cap Teflon coupling caps, custom resistors, and all the other extras for which we are known, the MA-1 shines as an example of why our amplifiers are the best amplifiers worldwide, regardless of cost.

• Balanced Differential Design®
• Class-A operation
• Patented Circlotronic® direct-coupled (OTL) output stage
• Automatic biasing system
• V-Cap copper foil Teflon coupling capacitors
• Built in VU meter for tube and output monitoring
• Easily monostrapped for greatly increased power
• 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
• Stable with all input and load conditions
• Exclusively uses Octal-Triode based vacuum tubes
• Classic open chassis construction with Wrinkletex™ finish
• Three-year general coverage warranty with one year warranty on output tubes.

Specifications :

Output power
• 140 watts per channel into 8 Ω load
• 135 watts per channel into 4 Ω load

• Input Impedance: 150 KΩ single-ended, 200 KΩ balanced
• Output Impedance: ~2.3 Ω (power method standard measurement)

• 2.8 V sensitivity
• RCA and XLR true balanced input

Tube complement
• (per channel) 14 x 6AS7G output tube
• 5 x 6SN7 driver tube

• 25 dB ( for 8 Ω )

Power Bandwidth
• 2 Hz-75 KHz within ½ dB

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

• Total Harmonic Distortion ( THD ) typically 0.5% at full power
• Intermodulation ( IM ) distortion typically under .005% at full power
• Phase shift less than 1° @ 20KHz

Output section risetime
• 600 V/µs

Power consumption
• (per channel) 500 watts

Power Supply storage
• (per channel) 600 Joules

• (per chassis) 18" deep x 17" wide x 8.5" tall ( 46 x 43 x 22 cm )

• (per chassis, without tubes) 36 lbs. ( 16.3 kg )

• Three year general coverage
• One year for output tubes

Optional Features and Accessories:

Optional Features
• Power Supply Boost
   uses custom built filter caps for MA-2
• Caddock® resistor package

Meter Panel finish options
• Gray hammertone
• Brushed anodized black
• Brushed anodized silver
• Brushed anodized gold
• Custom finishes available upon request

• 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 100.

• Balanced Interconnects
• Balanced phono cables
   1 meter, DIN to XLR or RCA with ground post to XLR