Class A Hybrid - tube/fet amplifier

Heros is a very unusual two stage hybrid transformer loaded amplifier marrying old concepts with latest technology.
The numerous benefits from using an output transformer are usually ignored mostly due to cost reasons. Yet when done correctly the result speaks for itself.

Heros Features:

  • Tube amplifier architecture with simplest signal path
  • Transformer coupled input and output
  • JFET/MOSFET cascode output devices
  • Silicon Carbide diodes in power supply
  • Microprocessor control
  • Selectable gain
  • Selectable speaker impedance
  • Audiophile 5687wa tube used
  • Fully balanced differential operation
  • Both RCA and XLR inputs
  • Compact chassis built like a tank
  • 100W ClassA power

Based on a standard cathode follower push pull output stage but modified with our design concepts and experience it features a tube input stage providing the necessary voltage amplification. Followed by transformer loaded cascoded jfet/mosfet output stage instead of the usual tube taking care of current gain much better.

Almost double the efficiency of a normal Solid State Class A design, no DC on output and many other benefits are taken advantage of in our implementation.

A fully differential architecture using an input phase splitting transformer and summing back at the push pull output transformer. This solution completely floats the inside of the amplifier isolating it from any external influences.

The design being fully differential is immune to power supply noise.

The power supply for the output stage uses a new breed of rectifier diodes made of a new material called Silicon Carbide. They have no reverse current and switching loses.

When properly applied the rectifier produces no EMI/RFI in the chassis.
The result is an amplifier free of grain and frizziness, giving new meaning to transparency and tone.

We use the well known 5687WA audiophile tube and the highest grade audio transformers.

The whole chassis is a heatsink. It is the most compact 100 watt class A solid state amplifier available.

Operating all devices in class ‘A’ produces a fair amount of heat.

The chassis is designed to cope with the heat produced by the components and provide a vibration free structure to house the components.
All the electronics are enclosed in separate compartments to stop interference between components.

Blending this with stylish aesthetics produced a beautiful sculpture - To be known as Heros.


  • Inputs
    - 1 unbalanced RCA connector
    - 1 balanced XLR connector
  • Output: 100W in 4Ω/8Ω
  • Power supply: 115 or 230 V
  • Power consumption: 230W
  • Dimensions: 210W x 400D x 230H mm
  • Weight: 30Kg
  • Finish: Black or Silver anodized aluminum
  • Tube compliment:
    - 1x 5687 amplification