Novacron Mk. 3.3 Limited Edition
monoblock music amplifier 
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 meter for monitoring tubes
  • 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, 90 day 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
4 x 6SN7 driver tube


24dB ( for 8 Ω )

Power Bandwidth

2Hz-100KHz within ½ dB

Frequency response

( 1 watt, open loop ) 20 Hz squarewave Tilt; unmeasureable
1Hz-200KHz within ½ dB (-3dB @ 1 MHz)


Phase shift less than 1° @ 20KHz

Output section risetime

600 V/µs

Power supply storage

600 Joules/chassis

Power consumption

400 watts


( per channel ) 16" deep x 16" wide x 6" tall ( 40.6 x 40.6 x 15.2 cm )


( per channel, without tubes ) 54 lbs ( 24.5 kg )


Three year general coverage
One year for output tubes
For all support requests, or any questions about your Atma-Sphere product, contact us directly at (651) 690-2246 or send us an email.

Optional Features

Caddock® resistor package


Contact your local dealer for pricing information.
Or, call (651) 690-2246 or email us with any questions.