[Aarmin]

This worries me:

"Caution: If you have high efficiency speakers with sensitivity > 92db, you might hear high frequency switching noise." 

I have a small wallet, and also want to get rid of my plastic multimedia speakers. My speakers are ratted at 94dB sensitivity, will I have to purchase less sensitive speakers? As donut as that sounds.

Why is it that the Icon has this issue? Just not as much "treatment" as the whopping more expensive stuff out there?

[nuforce-casey]

Nufoce amps are based on self-oscillation, and when there is no signal, the noise floor could elevate and you may hear it.  Icon has a S/N of around 90dB, so a 94dB speaker naturally you can hear the noise floor easily.
Icon Amp has lower noise floor than the Icon with more power, perhaps you can consider.

[vrankovic]

i have klipsch f1 ( 93db) ...absolutely no problem!

[lcrim]

I tried the amp w/ 96 dB. Omegas & 95 dB. Parker Audio 95 MKII and the noise was bad enough to return the unit. 
NuForce behaved impeccably throughout and accepted responsibility for the issue.  When I told them of my speaker's efficiency they knew immediately what the issue was.