1 (edited by Chippy_boy 2019-01-17 18:31:32)

Topic: Noise when switched off??!!

I'm the proud owner of a new ADI-2 Dac and am really delighted with the SQ and feature set - I think it's fantastic!

However, I've noticed a small problem:  When the dac is powered on, there is barely any background noise coming from my speakers, but as soon as I power the dac off, I get a quiet buzzing coming from the speakers.  It's not loud, but it's audible at 8 feet and is a bit annoying since I tend to leave my power amps switched on.

If I unplug EVERYTHING from the dac - even the power - it makes no difference; the buzzing is still there.  It only goes away when I switch the dac on.

Incidentally, this did not occur with the old Benchmark Dac1-hdr the ADI replaces. So I am guessing there's nothing grossly wrong with the rest of my equipment or setup.  The power amps are connected by the same XLR's as previously.

Does anyone know what's happening here... and more importantly, how I can fix it?

Thanks folks

2 (edited by Curt962 2019-01-18 16:19:09)

Re: Noise when switched off??!!

Chippy,

I've pored over your Post several times, and indeed this dilemna is puzzling.

With EVERYTHING removed from the DAC, yet still the persistent noise....this seems to conclusively remove the DAC from Suspicion.

It would would not be unheard of for a Cable to have failed, and is now functioning as an Antenna, collecting noises from elsewhere in the room.   Perhaps it would be possible for you to obtain a different set for trial.   

Best Wishes for a Speedy Resolution.

Curt

3 (edited by cake2pai 2019-01-18 18:29:15)

Re: Noise when switched off??!!

I am the same as you.
dac - xlr - poweramp - speaker
Noise is heard when turned off.
I have dac and pro.
I tested these two devices and it was the same.

Re: Noise when switched off??!!

Guys...I firmly believe a Cabling issue is at fault.  A completely disconnected Unit cannot be blamed for noise can it?

Re: Noise when switched off??!!

Just tested this with my Pro (AE) and huge midfield active monitors and don't hear anything. Only super low noise when I put head directly next to the speaker, but that is there always even when Pro is disconnected and is not audible 2 feet far.

Note that my speakers are connected over AES3, but I believe I've never heard any buzzing even before they were connected to analog XLR.

6

Re: Noise when switched off??!!

It's quite clear that the ground that is delivered over the cables is bad or missing, as the ADI-2's housing is connected to said ground, and would prevent whatever noise that could be there, as it completely encloses the inner phase lines (XLR pins 2 and 3).

Regards
Matthias Carstens
RME

Re: Noise when switched off??!!

I have a quite similar (very minor) issue, but clearly induced by USB.

My system: PC -> USB -> ADI-2 DAC -> XLR -> Neumann KH 310

Only if the ADI-2 DAC is switched off and in standby-mode i can hear a crackling noise from the speakers sometimes. It depends on what i do with the PC: I can reproduce it if i start a video - every time i doubliclick a video and the player (KMPlayer) starts to play i hear a little bit of crackling for a few seconds. The noise fades after a few seconds but comes again from time to time. When i close the player and start the video again i hear the noise again. It may have something to do with the graphics card, but i´m not sure. I have a GTX 770 in my PC.

It´s on both channels, i can hear it when only one channel (XLR) is connected, and i even tried a different XLR-cable. I only have Cordial cables with Neutrik connectors. I didn´t experience it with two different DACs before, so i´m pretty sure it has something to do with the RME.

If the DAC is powered on or if i unplug the USB-cable, there is no noise at all.

It´s a very small issue because i almost always power off my speakers when i don´t use the DAC but from time to time i experience the noise.

8

Re: Noise when switched off??!!

You have a ground loop via USB between computer and active speakers. Cheap solution: remove pin 1 from one side of the XLR cables. Pro solution: Intona USB isolator.

Regards
Matthias Carstens
RME

9 (edited by Chippy_boy 2019-01-24 19:23:59)

Re: Noise when switched off??!!

Thanks guys for thinking about this and for your helpful comments.

Curt962 wrote:

Guys...I firmly believe a Cabling issue is at fault.  A completely disconnected Unit cannot be blamed for noise can it?

Well, if I remove the ADi-2 Dac from the XLR cables (attached to the amp) then the noise stops.  So I would say pretty definitely the noise IS caused by the Dac!


Curt962 wrote:

Chippy,

I've pored over your Post several times, and indeed this dilemna is puzzling.

With EVERYTHING removed from the DAC, yet still the persistent noise....this seems to conclusively remove the DAC from Suspicion.

It would would not be unheard of for a Cable to have failed, and is now functioning as an Antenna, collecting noises from elsewhere in the room.   Perhaps it would be possible for you to obtain a different set for trial.   

Best Wishes for a Speedy Resolution.

Curt

If it was just one channel, I'd agree it has to be the cable.  But it's both channels.  And as I say, it didn't occur with the Benchmark DAC. It is indeed a strange problem.  I have two mono power amps, and if I disconnect one of them completely, so all I have is DAC (with no inputs and no power cable attached) > XLR > Poweramp > Speaker, then I get noise at the speaker.  If I attach the power to the Dac and turn it on, the noise stops.

It's clearly picking up noise from somewhere, but I have no clue how.  And why does the noise stop when the Dac is switched on? 

cake2pai wrote:

I am the same as you.
dac - xlr - poweramp - speaker
Noise is heard when turned off.
I have dac and pro.
I tested these two devices and it was the same.

Which would seem like one hell of a coincidence.  I wonder what your setup and mine have in common, which others do not???

Re: Noise when switched off??!!

Well, a small update.  It's NOT the cables.

This weekend I made up myself a pair of XLR cables with Van Damme star quad, silver-plated, OFC cable and Neutrik connectors.

Didn't make a blind bit of difference :-(  Buzzing from speakers when ADi-2 Dac is switched off :-(