Усилители для наушников — McIntosh MHA200

The MHA200 is a compact vacuum tube headphone amplifier from McIntosh, built around the Unity Coupled Circuit output transformer, the design with which the company started in 1949. Balanced inputs and outputs allow it to work with nearly all headphone types. McIntosh announced it on February 4, 2021, it went on sale in March 2021 at USD 2,500 in the USA and GBP 2,795 in the UK, and it is now shown as retired with only limited stock, backed by a 3-year limited warranty.

Key specs that matter

The amplifier delivers 500mW across all impedance settings, selected with a LOAD knob in four ranges of 32 to 100 ohms, 100 to 250 ohms, 250 to 600 ohms and 600 to 1,000 ohms. Voltage gain changes with the range - 12dB at 32 ohms, 17dB at 100 ohms, 21dB at 250 ohms and 25dB at 600 ohms. Frequency response is plus 0, minus 0.5dB from 20Hz to 20kHz. Distortion is 0.5% maximum at 250mW rated power across 20Hz to 20kHz and below 0.20% at 1W, and intermodulation distortion is 0.04% typical and 0.4% maximum. Signal-to-noise ratio is 94dB, damping factor exceeds 150, and dynamic headroom is 1.5dB. The balanced input has 20k ohm impedance and accepts up to 16V, while the unbalanced input has 10k ohm impedance and a maximum of 8V.

Engineering and use context

The 12AT7 dual triodes amplify the incoming audio signal, while the 12BH7A dual triodes supply the power that drives the output to the headphones through the output transformers. Shipping weight is 5.5 kg. Headphones connect through a pair of dedicated left and right 3-pin balanced XLR sockets, one 4-pin balanced XLR socket or a 6.35 mm stereo jack. The VOLUME knob has a unity gain centre point. A mirror-polished stainless steel chassis is used, with a protective tube cover in the box. It measures 15.6 cm wide, 14.6 cm high and 23.2 cm deep and weighs 4.8 kg. Power draw is 1.5A at 120V, 50/60Hz, and standby consumption stays under 0.5W.

Pairing

A source with balanced XLR or unbalanced RCA output connects directly, and Power Control input and output connectors allow remote switching of the MHA200 from a connected McIntosh preamplifier or integrated amplifier.

Alternatives

The McIntosh MHA150 is a headphone amplifier of the brand with a built-in DAC, Autoformer outputs for three headphone impedance ranges and 50 watt stereo speaker outputs.