Incase anyone cares. Just got this reply. Might clarify some stuff.
I sent this:
> Hello,
> I'm considering purchasing an Icon HD to use primarily as a DAC/headphone
> amp. However, in the future I may want to add a set of speakers/studio
> monitors to my collection. I'm wondering if the HD can be attached
> directly to a amp (which would then go to speakers) or if I have to
> connect to a preamp first?
>
> (note that I play all my music from a computer, so as long as the HD can
> act as preamp I don't really see any benefits of the HDP over the HD, is
> this correct?)
>
> Thanks,
> Chris
>
Got this reply:
Dear Chris,
When you connect headphones to the front of the Icon HD, the device acts as
a Headphone Amp. When you unplug the headphones an internal switch engages
the RCA Line level outputs on the back, which connect to an amplifier for
powering speakers.
When the headphone is unplugged, the Icon HD then acts as a regular
preamplifier and no longer a headphone amp. The analog volume knob controls
the preamp voltage to the RCA line outs. You send the RCA outs directly to
your amplifier.No other preamp is needed. You can go straight from the Icon
HD to an Amplifier.
Best Regards,
Jason Smith
NuForce Technical Support