Усилители для наушников — Musical Fidelity MX-HPA

The MX-HPA is a headphone amplifier from Musical Fidelity with a fully balanced topology. Single-ended input signals are converted automatically to balanced operation, so the signal path stays fully balanced whichever input is used.

Key specs that matter

Output power is 1.8 W per channel into 8 ohms, which equals 27 dBW. Maximum output voltage reaches 19 V RMS from 20 Hz to 20 kHz, the short-term peak is 10 W for one cycle, and clipping begins at 54 V peak to peak in balanced mode. Through the line input, frequency response is plus 0 and minus 0.1 dB from 10 Hz to 20 kHz, while the wider bandwidth figure is 10 Hz to 40 kHz at plus 0 and minus 3 dB. SNR is better than 120 dB A-weighted, THD+N is typically 0.005% across 20 Hz to 20 kHz, and input impedance is 50 kilohms. Gain is selected on the front panel and switchable between 18 dB, or 8 times, in the LO position and 24 dB, or 15 times, in the HI position.

Engineering and use context

The rear panel has one pair of balanced XLR sockets and one pair of RCA sockets. Headphones connect through a pair of combined outputs that each accept a 3-pin XLR plug or a 6.3 mm stereo jack, so the unit handles both balanced cables with two XLR plugs and ordinary single-ended headphone leads. The two gain settings let the same amplifier suit both sensitive and hard-to-drive headphones, and Musical Fidelity states that it will drive any headphone and delivers strong output into 32 ohms. The power supply accepts mains voltages from 90 to 250 V AC at 50 to 60 Hz, so no voltage selector is needed. Consumption is 15 W at full power and around 0.25 W in standby. The case is 220 mm wide, 53 mm high and 240 mm deep, with a weight of 2.2 kg unpacked and 3.7 kg packed. The MX-HPA is part of the compact MX series, was sold in silver and black finishes and carried a US retail price of USD 799.

Pairing

A source with balanced XLR outputs, such as a DAC or preamplifier, keeps the path balanced from end to end, while RCA-only sources connect through the unbalanced inputs. The MX-DAC from the same series shares the same width and height, so the two can form a matched stack.

Alternatives

The Musical Fidelity V90-BHA is a smaller balanced model in the same product category, specified at 0.75 W per channel into 32 ohms.