Raidho XT-3 Demo Used for Sale

Atma-Sphere MP-1 Rev 3.3 Tube Preamp (Consignment)

Original Retail: $22,200
Specially Priced At: $8,500

Atma-Sphere MP-1 MK 3.3 Tube Preamp

Customer consignment sale : Atma-Sphere MP-1 Mk 3.3 tube preamplifier in excellent condition. These have all the upgrades.  One owner, bought used from Atma-Sphere in 2008. Approximately 2 years left on manufacturer’s warranty. 

In 1989, the first MP-1 introduced balanced line technology to the world of high end audio. It was the first balanced, fully-differential preamp ever made, with innovations that were breakthroughs at the time and remain so today. With decades of refinement, patents and awards, the MP-1 is a paragon of the audio world.

The Mk. 3.3 update has affected the MP-1 more than than the rest of our lineup. More about that later… if the MP-1 is something you’ve not encountered before, it is unique in the world of preamplifiers. It easily outperforms conventional line stages and any passive or transformer volume control on account of its patented direct-coupled output which allows for greater transparency while also preventing coloration from interconnect cables. With only three stages of gain in the entire preamp (including the phono section), our Balanced Differential Design® is an elegant signal path that assures low distortion, wide bandwidth and dynamic range. No matter what you thought was the best, the MP-1 is an audible improvement.


  • Balanced Differential Design®
  • Supports the Balanced Line standard (AES48)
  • Robust output that can drive 32 ohm headphones
  • XLR connectors for phono and aux (paralleled RCA inputs optional)
  • Dual XLR output connections (RCA outputs optional)
  • Patented direct-coupled Circlotronic® output
  • Fully regulated supplies
  • Zero feedback design
  • Dual-mono construction
  • Differential passive phono equalization
  • Precision 24-position stepped volume control built from a Shallco® custom switch
  • Two tape monitors (tape functions use RCA’s)
  • Precision components used throughout
  • Total system phase switch
  • Teflon® custom coupling caps
  • Low-noise “star” grounding topology
  • Power supply isolated in seperate chassis
  • headphone compatible with a simple connector
  • optional RCA input and output connections available
  • other options: click on ‘Order’ above
  • Three-year general coverage warranty with one year warranty on output tubes





Line stage frequency response

.1 Hz – 400 KHz, +0 dB, -3dB ( -0.5 dB @ 250 KHz )


Line stage gain

12 dB


Line stage input impedance

100 K Ω single-ended / 200 K Ω balanced


Line stage output

32 V into 600 Ω



2 dB


Output impedance

30 Ω


Power Supply Storage

170 Joules


Tube complement

10 x 12AT7 (phono section)
6 x 6SN7 (line section)



( per chassis ) 13″ deep x 17″ wide x 5.5″ tall ( 33 x 43 x 14 cm )

Faceplate dimensions

( standard 3U rack, sans mounts ) 19″ wide x 6″ tall ( 48 x 15 cm )



( per chassis ) 42 lbs. (19 Kg)



Three year, transferable
One year for tubes