Great review: https://www.tonepublications.com/review/mcintosh-mha100-integrated-headphone-amplifier/
Selling my fantastic McIntosh headphone amp, was also using it as a 50W/channel rear-channel amp which worked wonderfully well, as well as DAC. It's in as close to brand-new condition as one can see from the pics.
Original box, manual, remote and power cord is included.
■ The new MHA100 is the first dedicated headphone
amplifier from McIntosh and employs a new
adaptation of our Autoformer technology to produce
three headphone impedance ranges of 8-40, 40-150
and 150-600 ohms so every headphone will produce
the best possible personal listening experience.
■ Features our new Headphone Crossfeed Director
(HXD) to allow high quality recordings to image like
conventional speakers in your headphones.
■ Four digital inputs allow the McIntosh Digital Engine
to decode your digital music at up to 32 bits and
192kHz for maximum analog fidelity and enjoyment.
■ Smaller, more compact size than other McIntosh
amplifiers allows additional flexibility in locating the
MHA100 in your space.
■ Includes 50 watt speaker output for when you
want to enjoy your favorite speakers instead of your
headphones, along with 5 Step Bass Boost Control
for further customization.
Identical unit is here on Audiogon for $3,200 and Reverb for $4,000!