Headphones

With no preamp/line output, the HA 200 really is a dedicated 'headphone driver' offering a number of very specialised settings to cater for the needs of enthusiasts owning multiple headphones. These include 8ohm, 12ohm, 18ohm, 25ohm, 40ohm and 80ohm source impedance settings, and 'Minimum', 'Low', 'Medium' and 'High' loudness level settings, none of which have any impact on the overall gain of the HA 200 (+14.1dB, balanced in/SE out). The loudness level settings do not influence maximum power output either, although the impedance settings absolutely do... In practice, maximum output is achieved via the '8R' setting at 1.65W/32ohm and 1.16W/8ohm [see inset graph – 8R (black into 32ohm; grey into 8ohm), 12R (red, 1.46W/32ohm), 18R (cyan, 1.09W), 25R (green, 0.95W), 40R (orange, 0.56W) and 80R (blue, 0.26W/32ohm)].

The impedance settings amount to 8.5ohm (8R), 11.2ohm (12R), 18.1ohm (18R), 22.5ohm (25R), 40ohm (40R) and 77ohm (80R), and all are 'flat' to within ±0.4ohm over a 20Hz-100kHz frequency range. So, while the HA 200's power output holds up well enough into 8ohm, there's still a 6dB signal loss (or 2dB into 32ohm) with similar swings in system response expected from low and irregular headphone impedances. Consequently I would not put the HA 200 forward as ideally suited to variable low impedance (sub-16ohm) 'phones/ear buds. Constant impedance (planar magnetic) headphones are favoured. PM