Усилители мощности моно — Aries Cerat CONCERO 65 SIG

The Concero 65 Signature is a single-ended triode (SET) mono power amplifier from Aries Cerat, the Cypriot high-end manufacturer led by its founder and designer Stavros. The Concero family comes in three versions - Reference, Signature and Limited Edition - and the Signature and Limited Edition move the power supply into a separate chassis. With 65W from a single-ended output stage, the Concero delivers far more power than typical SET amplifiers, which usually offer only a few watts.

Key specs that matter

The Concero 65 Signature delivers 65W per channel, with an impedance-match selector for 8, 4, 2 or 1-ohm loads and an output impedance of 1.6 ohms. The output stage uses two RCA 813 tubes in parallel, run in triode mode, and the driver stage uses an RCA 814 in triode mode, making it an all directly-heated-tube, transformer-coupled design. The power supply has a total power transformer rating of about 1,400 to 1,500VA, more than 700,000uF of capacitance across primary and secondary circuits and over 1,500 joules of energy storage. The noise floor is below -105dB unweighted. The amplifier and supply together measure 510 x 590 x 560mm and weigh 150kg per channel.

Engineering and use context

The 813 was originally designed by RCA as a high-voltage transmitting tube, and its high anode dissipation of 125W in triode mode is what allows a single-ended stage to reach 65W when two are paralleled. The stages are coupled by an interstage transformer with an amorphous C-core and bifilar winding rather than capacitors, and the design uses an AC link between the input and driver circuits. Aries Cerat builds its reservoirs from film supercapacitors instead of electrolytics, quoting about a thousand times the surge current rating and far lower equivalent series resistance and inductance, and combines them with a large choke in critically tuned LC filters. Separate toroidal transformers supply the output stage, driver and filaments, and every filament has triple pi-filtering to keep hum out of the directly heated tubes. Bias can be fine-tuned on the fly for both driver and output tubes, and an automated soft-start sequence brings the amplifier up gently.

Pairing

Its power reserve and impedance selector let the Concero 65 Signature drive a wider range of loudspeakers than typical SET amplifiers. It is at its best with high-efficiency loudspeakers such as Aries Cerat's own Symphonia horns, and pairs with the company's Impera preamplifiers.

Alternatives

Aries Cerat's own Concero 65 Limited Edition extends the same circuit with further power-supply upgrades and no capacitors in the signal path.