Усилители мощности моно — Ayon Audio Ayon Epsilon Evo Mono

The Epsilon Evo Mono is a true balanced valve monoblock from Ayon Audio, listed among the company's EVO mono amplifiers next to the Conquistador Evo, Vulcan Evo Trio and Orthos Evo. Ayon calls the Evo version a totally new design compared with the earlier Epsilon, with fresh operating and protection circuit boards, reworked gain and driver stages, a revised grounding layout, a new choke system and an updated bias system. Each channel runs six KT150 output tubes, and the maker also lists KT170 as an alternative tube type.

Key specs that matter

A rear switch selects pentode or triode operation. Ayon rates the output at 180 W in pentode mode and 100 W in triode mode, with class A given for the triode setting, and the output stage accepts 4 and 8 ohm loads. Bandwidth is 6 Hz to 70 kHz at -3 dB, while the quoted frequency response runs from 5 Hz to 80 kHz. Input impedance is 47 kohm at 1 kHz, 900 mV drives the amplifier to full output, and noise sits 98 dB below full output. Global negative feedback is 0 dB. Both RCA and XLR inputs are fitted. The chassis measures 35 x 60 x 25 cm (width, depth, height) and each unit weighs 44 kg.

Engineering and use context

For the output transformer Ayon adopted a new coil technology intended to keep the amplifier more stable in the low-frequency range, and the finished transformers are sealed in an anti-resonance compound. The power supply uses a pair of insulated mains transformers in RFI and EMI screened housings, a dual choke filter for the power tubes and another choke for the pre and driver stage, with regulated DC filament supplies and an AC line filter. Soft start sequencing completes the power-on cycle in one minute and limits in-rush current. The audio path contains no transistors and no follower or buffer stage, and a protection circuit watches the power tubes. Bias can be set automatically or by hand, read on an analogue meter. A ground switch toggles the switchable dual grounding system with a central star earth. Ayon produces its own valve sockets with spring pins of beryllium-copper, XLR sockets come from Neutrik and internal signal wiring is a silver-copper matrix. Ayon builds the anodised, non-magnetic aluminium case by hand, and it stands on resonance-absorbing aluminium feet and is offered in black or chrome.

Pairing

Ayon describes the amplifier as suited to difficult loudspeaker loads. The 900 mV sensitivity asks for a preamplifier with a healthy output, and the balanced input suits a fully balanced line stage.

Alternatives

The Ayon Orthos Evo is the bigger EVO monoblock, rated at 250 W in pentode and 170 W in triode mode with 1000 mV sensitivity and a weight of 52 kg.