Does anyone at HA have specific info regarding exactly how iPods are volume-capped?
The two scenarios I see are
1. Capping is done similarly to how EQ is performed - digital data is modified (in this case, scaled).
2. Capping is done by limiting the maximum post DAC analog gain stage.
The analog gain stage in the codec just ahead of the headphone amp is programmable from -73dB to +6dB in 1dB increments, and would seem to be the easiest and most power efficient place to perform the cap. Can anyone confirm this?