I mainly use high-res files for critical stereo-listening over speakers.
How suitable is the Geek V2's output impedance /level configuration, etc. for that job?
For example, the Pono has separate outputs for headphones AND line-level. Geek V2 does not have that.
Thanks for any enlightening information.
I've not tried this, but typically it's possible.
It's normally a good idea to match impedances to make this work. A V2 is expecting to see a 16-300 ohm impedance on its output. An amplifier's input impedance is usually 20-50k ohms. This is mis-matched. So you can put a high wattage resistor (say about 220 ohm, 1w, wire-wound) which is rated at 10x the actual wattage used (v squared/ohms) across each v2 output channel, and, in parallel, connect it to the line-in of the amplifier. You'll need 2 of these for the stereo channels of an unbalanced connection, 4 of them for a balanced connection. Personally, I'd only ever use this method, short-term, and if I were running it into a pre-amp stage with tone controls.
The superior way of matching impedances is with a small audio transformer, eg a Lundahl transformer. Superior and much more expensive! These match the impedances better at ALL audio frequencies (eg it looks much more like a headphone to the v2 output).
Of course, Larry Ho is the expert on this. You might get a (lot better) answer from the v2 forum on headfi.org.