“In designing the Concero directly heated Tube Monoblocks we endeavoured to produce a design that has all the sonic virtues of the best Single Ended amplifiers, but with absolutely none of their shortcomings. In other words, with no limitations AND all of the benefits sonically of true SET amplification. We strongly believe we have succeeded.”

Stavros Danos

Driving the output tube, is a major task, where almost all SET amplifiers fall short and using tubes not adequate to the task. Tubes with high Rp and small current swing capabilities. What we choose to use is a small SET amplifier consisting of the special quality Siemens E280F super-tube, with it’s own power and bias supply.

This ultra wide-bandwidth and very high trans-conductance tube is transformer coupled to the grid of the output tube using a very wide-bandwidth interstage transformer. No RC coupling is used in any of our amplifiers.

Output is rated @ 65W, via a massive output transformer, with 4 and 8 ohm taps.

The output transformer weighs more than many SET amplifier’s total weight. The highest quality massive core of the output transformer used in the design, is mandatory for delivering true undistorted higher and lower bass, and driving any speaker through complex musical content.

Many SET amplifiers exhibit distortion when driving speakers with complex music due to core saturation. Our output transformer can output well above it’s rated power at 20Hz,so at 65W intermodulation aftefacts are next to zero.

Separate power supplies are used throughout our design, using 4 toroidal transformers rated at over 1500VA total.
Separate toroids are used for driver stage, output stage,filaments and bias circuits.

Driver and output is ground-choke regulated with huge energy banks for each channel.
The Concero 65 are available in two chassis options, classic and the more compact 2018 facelift version.

814 DHT tube, amorphous C-Core,bifilar wound interstage transformer
High power film capacitor (choke regulated) banks
Triple filtered filaments
Parallel 813 SET stage,ultra low noise adjustable bias circuits
High power film capacitors, choke regulated banks
The film Capacitors used,have ~1000 times the max current surge rating than any electrolytic used in other amplifiers,and 10 times less ESR/ESL than any electrolytic capacitor
Choke used is a 11kg-core inductor, providing extra energy storage
Triple filtered filaments
Oversized ,highest quality output transformer
700.000uF total primary and secondary circuits capacitance
Separate toroidal transformers for output stage,driver and filaments, 1500VA total
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Dimensions: 580mm W x 480mm D x 360mm H
Weight: 100Kg unpacked