Усилители для наушников — Cayin HA-300 MK3

The HA-300 MK3 is the third generation of the Cayin 300B headphone amplifier, a single-ended pure Class A tube design split across two chassis. It follows the HA-300 Mk2 with a fully upgraded wide-bandwidth transformer set, a revised power delivery topology and wider headphone compatibility, from sensitive in-ear monitors to demanding high-impedance full-size models. Cayin calls it the top of its headphone amplifier range. Speaker terminals let it drive loudspeakers as well.

Key specs that matter

Two Genalex Gold Lion PX300B direct heated triodes, supplied as a matched pair, form the output stage and are driven by two 6SN7 tubes for voltage amplification, while two GZ34/5AR4 tubes rectify the supply. Output reaches 6,500 mW per channel from the 4-pin XLR balanced socket, 6,000 mW from the 6.35 mm jack and 1,600 mW from the 4.4 mm Pentaconn socket. A three-position impedance selector covers 8 to 64 ohm, 65 to 250 ohm and 251 to 600 ohm loads. The rear panel carries XLR balanced and RCA single-ended line inputs, with input sensitivity from 250 to 1,200 mV. THD stays below 1 percent at 1 kHz, and the speaker terminals accept 4 to 8 ohm loads. The amplifier chassis measures 286 x 368 x 205 mm and weighs 16.8 kg, while the separate supply measures 159 x 345 x 205 mm and weighs 10 kg.

Engineering and use context

A dedicated supply enclosure keeps transformers and rectification away from the signal circuitry to cut electrical interference. The amplifier uses third-generation broadband EI output transformers wound in-house, a toroidal mains transformer, Duelund coupling capacitors and gold-plated tube sockets, and all signal connections are made by hand without circuit boards. Volume is set by a JRC MUSES 72320V chip together with an ALPS 41-step attenuator. Two VU meters sit on the front panel, and a 60-second mute delay protects the outputs during the first minute after switch-on. Owners may roll tubes freely, and Cayin specifies a 48-hour break-in period for new tubes.

Pairing

A balanced DAC with XLR outputs uses the full input path, and full-size headphones with 4-pin XLR cables make use of the highest power rating. Low-sensitivity planar or high-impedance dynamic headphones suit the high and medium impedance settings, while in-ear monitors belong on the low setting. A pair of efficient loudspeakers can also be run from the rear speaker terminals in a small room.

Alternatives

The Cayin HA-6A Mk2 is a KT88 tube headphone amplifier with switchable triode and ultralinear modes, also built on two chassis.