Усилители для наушников — Cayin HA-6A Mk2

The HA-6A Mk2 is a two-chassis tube headphone amplifier from Cayin that uses KT88 power tubes and offers a choice of triode or ultralinear wiring for its output tubes. The change can be made from the front panel while the amplifier is running, with no need to power down. A dedicated preamp output lets it also serve as a line stage feeding a separate power amp or powered monitors.

Key specs that matter

The tube line-up consists of two ECC82/12AU7 dual triodes for voltage gain, a matched pair of Genalex KT88 output tubes and two GZ34/5AR4 rectifiers. From the 4-pin XLR balanced socket it delivers 4,500 mW per channel in ultralinear mode or 3,000 mW in triode mode. Into 32 ohm the 6.35 mm jack gives 3,500 mW ultralinear or 2,300 mW triode, and the 4.4 mm Pentaconn socket gives 1,000 mW or 650 mW. Frequency response runs from 10 Hz to 26 kHz within 3 dB, signal-to-noise ratio is 104 dB A-weighted and THD is 0.3 percent at 1 kHz and 200 mW. An impedance switch offers low, medium and high positions covering 8 to 64 ohm, 65 to 250 ohm and 251 to 600 ohm. Line inputs are provided on both XLR and RCA connectors, so balanced and single-ended sources can stay connected. The amplifier unit measures 285 x 185 x 297 mm and weighs 11.2 kg, and the power supply measures 160 x 195 x 297 mm at 8.2 kg.

Engineering and use context

The outboard supply enclosure keeps mains and rectifier parts apart from the amplifier circuitry to lower noise. The output stage accepts several alternative tubes besides the KT88, including EL34, 6550, KT66 and KT150, so owners can experiment with other types. A 60-second soft start delays full operation after switch-on, and volume runs through an ALPS potentiometer. Triode mode trades output for a different operating point, while ultralinear mode raises the available power on every socket. The three headphone sockets share one volume control, so only the connector matching the headphone cable needs to be used.

Pairing

Planar magnetic and high-impedance dynamic headphones benefit most from the balanced XLR output and the higher ultralinear rating, while sensitive models suit the low impedance position. A source with XLR sockets can connect through the balanced input to keep the signal balanced up to the amplifier. Through the preamp output, a solid-state or tube power amplifier can be added to run loudspeakers from the same source.

Alternatives

The Cayin HA-300 MK3 is a 300B single-ended Class A headphone amplifier, also on two chassis, rated up to 6,500 mW per channel from its XLR output.