ZOTL40 designed by David Berning.



A new amp by David Berning, ZOTL inventor, the ZOTL40 is one of his finest works yet.  Showcasing a designer at his best, the ZOTL40 Power Amplifier provides two 40W outputs with accurate, uncolored sound with automatically protected circuitry.  With such rapid response, detailed sound, and absence of tube bloom typical of other amplifiers, the ZOTL40 Power Amplifier sets itself apart as best-in-class, producing an unforgettably palpable and poignant listening experience every time.

ZOTL40 Power Amplifier

Hand-built in Washington, DC, with premium components, the ZOTL40 is available through HiFi Logic..  

Performing at the theoretically correct turns ratio, Linear Tube Audio’s ZOTL40 delivers a previously unattainable, unparalleled and stunningly realistic experience wherever it's plugged in.  Considered the only significant advance in tube circuitry since the 1960’s, ZOTL technology eliminates the output transformer in order to remove the inherent distortion found in transformer-type amplifiers.  

Perfect for high efficiency speakers, the ZOTL40 produces a much lower hum than most tube amplifiers and requires no adjustments since tubes are auto-biased.  With Russian Tung-Sol tubes, push-pull Class AB output stage, an Alps volume control and inputs for direct connection to high output sources, theZOTL40 Power Amplifier delivers a potent, experience defining realism.



  • Designed by David Berning - one of the world’s premier amplifier designers
  • Hand-wound coils & impedance converters
  • 40 watts per channel with little or no hum
  • Frequency response flat from 8 hz to almost 50K hz
  • Transformer-less design eliminates intermodulation distortion inherent in all transformer designs
  • Impedance converters simulate correct theoretical output transformer turns ratio
  • Low impedance output easily matches a wide range of speakers and cannot be damaged with no load
  • No adjustments – tubes are auto-biased
  • Automatic protection circuitry
  • High voltage turn on delay to maximize tube life
  • 10 - 20 years tube life depending on use
  • Push-pull, Class AB output stage
  • No heavy power or audio transformers
  • Universal voltage power supply (autosensing 100-240VAC 50/60Hz)
  • Has one input through Alps volume control for direct connection to high output sources
  • Second set of inputs bypass volume control for direct input


Premium Components

  • TUNG-SOL Russian vacuum tubes
  • Locking headphone jack w/ silver contacts
  • Silver-coated Teflon copper insulated wiring
  • Alps volume control
  • Hand-wound coils & impedance converters
  • Gold connectors throughout signal path
  • 5-way gold binding posts  
  • High quality metal film resistors  


Architecture by Lucegroup