FInally I have a noise issue

Its a common fault with components that have any type of "isolated" power supply, like...

battery powered components like tablets, phones etc..

• CD/DVD players with 2 pin power supplies
• (Some) Bluiesound products
• many other products like the bluesound

Yesterday it was the iPad with the only cord being the earphone.

Last night I noticed I also had the higher frequency noise coming in on the TV input.

This morning I disconnected the USB connecting the RME DAC (ADC) to the computer and the noise went away on all sources.

Next I’ll try and free up a place to plug the laptop into the same strip as the stereo gear.

Sort of defeats the purpose of a 24 bit ADC, when the noise floor is toggling over half of the bits.

Thanks @williewonka 

Seems this new-fangled digital gear isn't foolproof.

A bit like the fact that after 25 or more years of development internet connections still aren't stable.

Hi there,

I sometimes use an iPad as a cable-connected audio source, like I guess many people here do.  I found it is essential to be not charging at the same time.  You must have only the audio headphone/lineout wire connected.  Any other connection will cause two things  a hum loop (line frequency 50 or 60Hz tone) and the horrid switching noise and RF junk that comes out of all basic phone/usb chargers.  It can have a nasty subliminal burbling sound that is not completely audible most of the time but is nevertheless destroying many details in the sound.

With only the one connection from iPad ( or phone) to line-in I find the fidelity is not bad and the noise floor is pretty low.

Hope this helps,

...all the above applies to laptops.  When it comes to desktops you need different solutions (e.g. isolation transformers) as, obviously, you cannot disconnect the mains supply to the computer.

Word @adambennette and @clearthinker 

I always ply the iPod without charging, mostly because the one hole cannot do charge and plat at the same time.

The DAC/ADC was a surprise though.

I can see why I like vinyl… this digital stuff if difficult.