David Berning Co Quadrature Z 220 wpc OTL

I am the global and exclusive ’direct to client’ sales agent of the David Berning company. 

Rick Brown
rbhifi1.com
[email protected]
612 817 1599

The David Berning Quadrature Z 220w (ZOTL Zero-Hysteresis Output Transformerless) mono amp utilizes a patented impedance converter made possible by new technology which replaces the traditional audio output transformer. A seminal piece of audio technology that has sustained its superiority for over 15 years!

Hi Fi Plus power amp of the year 2009.

Technically speaking, hysteresis distortion affecting all frequencies, magnetizing current affecting the bass, and parasitic capacitance affecting the highs are eliminated. This enables the Quadrature Z to convey the musical transparency of tubes without the limitations imposed at the frequency extremes by audio output transformers.

The midrange immediacy associated with tubes is preserved while the listener experiences solid state-like quickness and bass control. The traditional OTL (Output Transformer-Less) tube amplifier first developed in the 1950s is sought after for the elimination of the output transformers coloration. The traditional cost -- reliability issues associated with the large number of hot running power tubes needed to obtain sufficient current to drive speakers. The typical conventional OTL uses the 6AS7  tubes -- twenty per channel -- which output a nominal 220 watts.  

The Quadrature Z four 33JV6 tubes per channel for a nominal 220 watts! 

Even with a large number of tubes, bass control is usually poor and compatible speaker selection is critical. The Berning ZOTL technology provides all of the OTL sonic benefits combined with constant output impedance over the entire audio spectrum.

Proper impedance matching allows the Quadrature Z to superbly drive a very wide range of speakers (including MBL 101's) with 4 33JV6 output tubes (per mono chassis) while generating 220 wpc.

Other benefits include the use of sophisticated, fully regulated, power-factor-corrected power supplies coupled to tube auto-biasing, smart protection circuits and Stillpoints circuit board and chassis isolators.

The elimination of the large line-frequency power transformer and the output transformer cuts the weight of the ZOTL amplifier to roughly a third of the weight of a comparatively powered tube amp.

220 watt per channel OTL incorporating the latest circuitry trickled down from the flagship 60 watts per channel class A 211/845 OTL. The QZ amplifiers will drive very difficult loads like the MBL 101 and Maggie 20 loudspeakers based on their ZOTL impedance matching patented circuitry. There are no other OTL’s and very few vacuum tube amplifiers that can make this claim. Load tolerance is one singularly unique Berning OTL attribute. Transient speed, bass impact, transparency and lack of coloration are exemplary and well chronicled in many reviews all over the world. No other OTL can produce 220 wpc with a total of 4 output tubes per channel. All other OTL amplifiers are conventional with all the caveats that accompany directly driving a loudspeaker w/o an output transformer. The QZ is an innovative, patented and technologically advanced tube amplifier utilizing a high-speed Berning designed and built switch mode power supply and full power factor correction. Moreover, the 33JV6 output tubes will last a minimum of 10,000 hours and many have been running with the original tubes for over 15 years. That is only possible running the tubes as they were intended by their mfg’s to be utilized. Not like all other hot running, short tube life, conventional OTL competitors. These amplifiers have built-in AC filtration, weight 38 pounds each, self-bias and run anywhere in the world without adjustment. Plug-n-play. They stand alone where high power OTL amplification is concerned today just as they did when introduced over 15 years ago. Truly ’technology in the service of music’. Stillpoints Ultra feet are fully integrated and the full factory 2-year warranty is in effect the day of purchase.

Wire transfer is preferred. PayPal accepted plus 3% or Friends and Family.