USB Input causes noise across whole amplifier - Musical Fidelity M5si

@photon_arts You can find them from around $30 I think.  Just make sure it supports high speed 2.0.

It does stink, especially when I have seen some mega-buck DAC vendors sell this as a huge upsell. 

And it's also upsetting because 90% of the time there  is a USB ground loop problem it is NOT audible hum.  It's really bad jitter which listeners may never know about.  They'll hear it in lack of clarity, focus and harshness, but without a jitter analyzer they would not know they had an issue.

It is only a very small amount of USB ground loop issues which show up as audible humm. 

Hi carlsbad,

Thanks for the suggestions.

The computer and integrated amp are on different areas of the room. The comp is on it's own surge protection; the amp is direct into the mains. I have tried reversing the amp power polarity.

I'll try running a line from the same socket to the comp to see if that has any affect.

Thanks.

You need a dedicated USB card with external power.

Matrix usb h via battery power takes all the motherboard noise out of the chain, USB is a dirty signal, and will cause noise issues up and down the entire frequency.

I have a picture of a modded card as my avatar ^^^^

Thanks.

I need flexible options right now, as I'm going through some component failures and repairs, changing of systems, and eventual moving house. I wanted the USB capability to provide one aspect of this flexibility.

I'm disappointed that the USB input is not at all isolated from the rest of the preamp, thus allowing the noise to bleed into all uses of this integrated (not in a good way here) amp.