Preamp output impedance of 0 ohms is ideal, but impossible. It is quite common for preout impedance to be very low, many of the opamp preouts go less than 1 ohm with .3 ohm being quite common (and nearly ideal). Looks to me that is what the AMS chip utilizes. That’s probably why the preout (lineout) drives ear buds quite well. I would not use much less than 32 ohm load though (due to current draw), and nothing with large voice coils.
Mini jack shorting spikes due to dv/dt? Doesn’t seem to be a problem with my jumped cable connected hot multiple times with no resistors added.
Fuze to iPod adapter? Probably quite easy if the dock only needs a lineout signal and device detect. Volume control may get involved depending on how/if it is done. A cable is possible, but the player would not sit in a dock. It would be better to modify the dock internally so the player could sit in it.
Griffin volume control back? Reload firmware 11 or 15 or modify dock by adding a dual attenuator pot.
