Усилители для наушников — Bryston BHA-1

The BHA-1 is a balanced headphone amplifier and preamplifier from Bryston, the Canadian electronics maker. It was released in 2012 at USD 1,395 and remains in production, now at about USD 2,495 to 2,695. It is a purely analogue design built around discrete Class A circuits, with no digital inputs.

Key specs that matter

Bryston rates the output at 2 W per channel into 32 ohm. Gain is switchable between about 14 dB and 20 dB. THD+N stays below 0.005% from 20 Hz to 20 kHz at rated power, intermodulation distortion is below 0.001%, signal to noise ratio exceeds 105 dB, and frequency response is 20 Hz to 20 kHz ±0.1 dB. Inputs are RCA, XLR and a 3.5 mm stereo jack, with an input impedance of 10 kOhm unbalanced and 15 kOhm or 5 kOhm balanced. Headphone outputs are a 6.35 mm single-ended jack, a four-pin XLR and a pair of three-pin XLR sockets, and a rear pair of XLR outputs lets the unit work as a line preamplifier. The faceplate is either 432 or 483 mm wide, the case is 69 mm high and 282 mm deep, and the amplifier weighs 5.3 kg. Faceplates are silver or black, and Bryston gives a 10-year warranty.

Engineering and use context

The circuit uses six discrete Class A operational amplifiers built from individual transistors rather than integrated chips, arranged in a dual-mono balanced topology. Dual mono means each channel has its own complete signal path, which keeps crosstalk low, and the balanced layout drives each side of a headphone driver with its own amplifier when a balanced cable is used. The amplifier is cooled by convection only, so it runs without a fan. Power comes from an internal analogue supply, and the optional external MPS-2 power supply can take over this role. Balanced headphones connect through the four-pin XLR or the dual three-pin XLR outputs, while conventional headphones use the single-ended jack. A phone or portable player plugs into the front mini-jack input. When the rear XLR outputs are used, the BHA-1 can control the level of a power amplifier or active speakers, turning it into the centre of a small system as well as a headphone amplifier.

Pairing

Demanding headphones draw on the full output at the high-gain setting, and the low-gain setting suits sensitive in-ear models. A DAC or CD player with balanced outputs connects to the XLR inputs to keep the path balanced end to end.

Alternatives

Bryston has no other headphone amplifier in its catalogue.