NAP100 causes speaker to hiss when using headphones on UnitiCute2.

Posted by: Mike Sullivan on 10 July 2018

i have an unusual problem. I have a NAP100 next to my UnitiCute2. When I plug headphones in to the Cute, there is a low, but audible, hiss from the speakers. Removing the interconnects makes no difference. If I turn of the NAP100, the hissing stops. So it seems like some electrical interface that only happens with the headphone switching the sound output modes.

Any pearls of wisdom?

Posted on: 11 July 2018 by james n

Mike, The UQ2 mutes speakers and pre-outs when the headphones are plugged in. From what you say it sounds like the pre-outs aren't actually muted but go open circuit hence the small hiss (the same as you get if you remove the interconnects to the NAP100). You may have very sensitive speakers or sit close to them which makes you notice the hiss more. As you say it's a characteristic of the way the headphone switching works on the UQ2 so there's not a lot you can do to stop it.

James

Posted on: 13 July 2018 by Mike Sullivan

james n posted:
Mike, The UQ2 mutes speakers and pre-outs when the headphones are plugged in. From what you say it sounds like the pre-outs aren't actually muted but go open circuit hence the small hiss (the same as you get if you remove the interconnects to the NAP100). You may have very sensitive speakers or sit close to them which makes you notice the hiss more. As you say it's a characteristic of the way the headphone switching works on the UQ2 so there's not a lot you can do to stop it.
James

Thanks for the information James. It’s good to know that nothing is wrong. I also asked my dealer, who indicated that this is the way the Naim amps run, something to do with electrical shielding protocol. Anyway, all is well. Have fun.