2. amps-preamps
  3. 173568-168155

USB Input causes noise across whole amplifier - Musical Fidelity M5si

Hi,
Has anyone experienced this:
 
If a computer is connected to the USB input, the noise level of the amplifier is raised across ALL INPUTS. This is not a 60hz hum. There is an upper mid-range whine/tone and some crackle. This is audible regardless of which input is active. IOW, when using any input, such as AUX2, this noise is present, until the USB cable is disconnected. Apparently there is bleed through the whole system.
 
I have tried different USB cables, USB2 and USB3, USB cable with an incorporated choke. The effect is the same. The noise comes on about 2-3 sec. after connecting the USB cable.
 
This is a new, recently purchased unit.
 
Thanks for any insights
photon_arts
runwell
280 posts
 

If that is the case,do not use the internal DAC.

I have bad experience to use USB port in hifi system,so since then I never use USB port in hifi system again. Now I use optical port,the sound is very good.

photon_arts OP
6 posts
 

Thanks, but this integrated amp doesn't have an optical input.

runwell
280 posts
 

Yes,I know. Just leave the internal  DAC there,you have no way to use it.

Add external DAC if possible.

 

 

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