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Atma Sphere Novacron
Limited Edition

Hi-End tube amplifiers, OTL monoblocs, 2 x 60 watts, Mk 3.3

Atma Sphere Novacron

Originally introduced in 1991, the Novacron was the first US product to use the classic 6C33C Russian power triode. Just over twenty years later, Atma-Sphere is pleased to announce the return of the Novacron, now updated to Mk 3.3. 

In 1991, not only was the amplifier on the cutting edge of high-fidelity sound reproduction, it was an outstanding example of aesthetic industrial design. Today, the new Novacron combines the characteristics of the 6C33C triode with the same legendary circuit topology that has made our other amplifiers famous. Recent advances have rendered the Novacron even more reliable, easier to use, and inherently musical; maintaining the proper balance between sound and circuitry.

Designed for reproducing music, not sine waves, the Novacron tracks dynamic waveforms faster than any other amplifier in the world. It naturally uncovers more detail than an ordinary amplifier, realizing your music as it was meant to be heard.


- Balanced Differential Design®
- Class-A operation
- Patented Circlotronic® direct-coupled (OTL) output stage
- Dual-mono chassis construction
- Copper foil V-Cap coupling caps
- Teflon output tube sockets
- Simple manual bias system
- 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 electronics - no circuit boards!
- Stable with all input and load conditions
- Three-year general coverage warranty, one year warranty on output tubes


Output power
60 watts per channel into 8 Ω load 

Input Impedance: 100 KΩ single-ended, 200 KΩ balanced Output Impedance: ~2 Ω

3 V sensitivity, RCA and XLR true balanced input

Tube complement
4 x 6C33C power triode ( per channel ) 
4 x 6SN7 driver tube ( per channel ) 

24dB (for 8 Ω)

Power Bandwidth
2Hz-100 KHz within ½ dB

Frequency response
(1 watt, open loop) 20 Hz squarewave Tilt, unmeasureable
1Hz-200KHz within 0.5 dB (-3dB @ 1 MHz)

Power supply storage
600 Joules / chassis    

Phase shift less than 1° @ 20KHz 

Output section risetime 
600 V/µs 

Power consumption
400 watts ( per channel )

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 

Three year general coverage
One year for output tubes

Optional Features

Caddock® resistor package


Balanced Interconnect
Balanced phono cable
1 meter, DIN to XLR or RCA with ground post to XLR 

For additional informations, audition and pricing, contact our worldwide dealers, or our headquarters.


Atma Sphere
1742 Selby Avenue
St. Paul, MN 55104


Tel : +1 651-690-2246