Headphones amplifiers — Erzetich Audio Deimos

The Deimos is a headphone amplifier from Erzetich Audio, the Slovenian workshop based in the woods of Trnovo near the Italian border. Founder Blaž Erzetič built his first amplification system at 16, and the Deimos distils that background into a dual-mono Class A design housed in a deliberately industrial chassis with an aged linden wood faceplate and thick milled aluminium parts. It was first shown at High End Munich and launched in early 2015 at around EUR 4,000, with a very limited yearly production because every unit is hand-built.

Key specs that matter

The Deimos is a dual-mono Class A amplifier with three separate power supplies. Frequency response is 4 Hz to 40 kHz within 1 dB. Volume is set by a digitally controlled, relay-based attenuator with 64 steps, and a gain boost switch is provided. Inputs are RCA and XLR, the latter on gold-plated Neutrik connectors. The chassis measures 320 x 125 x 330 mm, weighs over 6 kg and is built from steel, aluminium, wood and acrylic. It is specified for headphones from 8 to 600 ohm.

Engineering and use context

The three power supplies are the core of the design - one feeds each audio channel and the third powers the digital control section, so neither channel shares a supply with the other or with the logic circuitry. This isolates the channels from each other and keeps switching noise from the control electronics out of the audio path. Each channel has 43,000 uF of smoothing capacitance, giving a large energy reserve for stable operation into demanding loads. Class A operation keeps the output devices conducting at all times, avoiding the crossover region of Class AB designs at the cost of higher heat and power draw. The relay attenuator switches fixed resistor networks instead of turning a potentiometer track, which keeps the two channels closely matched at every setting and follows a controlled logarithmic scale, even at the low volume positions where conventional potentiometers tend to drift out of balance. The gain switch lets one amplifier serve both sensitive in-ear monitors and inefficient full-size headphones.

Pairing

The wide load range covers low-impedance planar-magnetic headphones as well as high-impedance dynamic models, and the gain boost helps with low-sensitivity planars. XLR inputs allow a balanced connection from a DAC or preamplifier, while RCA suits single-ended sources. Its substantial footprint calls for a dedicated shelf or desk space with room for ventilation around the Class A circuitry.

Alternatives

Erzetich Audio's own Perfidus is the brand's more compact and affordable headphone amplifier for smaller desks and lower budgets.