FInally I have a noise issue

@holmz - RE:

Should I wind a copper wire around the thing and attach it to the preamp ground as a test?

Wrap a wire round the neutral of one of the phono plugs and ground it at the outlet

BTW - it could be the souce and NOT the cable

• I had a DVD player that caused hum
  • tried everything but still hummed
• grounding the neutral of an input on the amp fixed it
  • the DVD player had an isolated (i.e. 2 pin) power supply

My Bluesound Node 2 causes a hum...

• i.e. IF, the phono stage (which is correctly grounded) is not connected to the system

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

Hope that helps - Steve

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.

@holmz 

Yes.  As you may have guessed I listen nearly exclusively to vinyl with only a little CD/SACD and no streaming or rips.  In any case, it's the artists who are getting ripped.

On your iPod, maybe there's a good reason why they only give you one hole?

It's still amazing how many people think that digital is the final and complete answer to everything (not just in hi-fi) with all upsides and no problems.  IT has a long way to go before its brain is as big as mine.  And yours.

@adambennette 

Actually, it's surprising how often I have to cut the mains to my desktop when it locks or operates very slowly.  It is old though and true that junk gradually builds up on hard disks and cannot ever be cleaned fully, even with programs like Norton and others.

@clearthinker I abide the vinyl fine.
This ADC (and an 8 channel DAC) is my first real foray into digital gear… and the ADC is specifically for measuring the TT stuff. 😋

@holmz 

Thank you.  I am interested in the measurements you are proposing to make of your TT using the ADC.  My arm is parallel tracking so it is much easier than a pivoted arm to set up completely accurately by eye without recourse to measurement by instruments.

Maybe it is the source?

just pointing out that al the discussion of new fanged digital misses the point.  The TRS to RCA cable and the connection is analog.  The noise is ground noise.  No digital involved.

Funny, don't experience any noise with the 'droid phones I've owned....

Just dumb lucky, I guess...😏

Maybe it is the source?

It was the USB connecting the DAC to the computer that was the source of the hash/noise.
And it appeared on all sources as a ground loop type of input..

@holmz 5M 1/8” (3mm) headphone jack to RCA lead…USB cable injecting noise…man oh man…should be enough length to tie your garbage bags for the next 4-5 weeks if cut to correct size. Once you’re done with it, get yourself a set of good cables.