Strange Digital coax issue with Dacmagic

[kevinJ]

I have a Denon avr1909, denon dvd1740 and dacmagic installed in the bedroom, where I have 2 electrical adjustable beds too.
Since I also use the dvd1740 to listen to cd's, I added a dacmagic a while ago, and then the strange issue started.

I used a Chord Codac Silver Plus to connect the dac to the dvdplayer, and Chord Cobra3 to connect the dac to the receiver.

When I want to raise or lower the leg or back section of a bed when playing a cd, the music stops for a split seconde. That same issue happens when using a Wireworld chroma 5 coax cable too, so it's not a deffective Codac. And that problem only occurs when listening to a cd. Dvdplayback is no problem at all (and the signal also passes the dacmagic).

But the strangest thing is: I didn't have that problem before I added the dacmagic. When I first bought the dvdplayer and receiver, I just used that wireworld coax cable to connect them. Changing the possition of a bed never interrupted musicplayback back then.

Now I have the dvdplayer connected to the dac with the cheapest optical cable, and there is no issue anymore.

So my question now is: is the dacmagic that sensitive to electrical noise/pulses? And why only when listening to cd's and only when using a digital coax cable?

 

[Andrew Everard]

Sounds like the bed motors have a switch or something that's creating RFI, which is being picked up by the cable and causing the DM to momentarily lose lock with the digital signal. The fact that the optical cable connection isn't affected suggests it's a cable problem, rather than in the DacMagic.

 

[kevinJ]

thanks for the reply Andrew,but why would that issue only occur when listening to cd's? A dts/dd-signal passes the same cable, but doesn't make the sound interrup. So maybe it's only when the dacmagic is actually "dac-ing".

And also, when the dvdplayer is connected only to the receiver, and having that receiver do the digital-to-analogue conversion, the signal is never interrupted.

I've been breaking my head on this one for a few weeks now.

btw, adding a mains conditioner doesn't seem to help either.

thank god for optical cables

 

[Andrew Everard]

It could be that the DacMagic is more sensitive to momentary breaks in digital signal than your receiver, and takes slightly longer to re-establish lock, so you hear the break when using it, and not when using the receiver. That's a lot more likely that the digital signal format having anything to do with the problem.

 

[kevinJ]

That sounds very resonable.

I'm going to try an old dvdplayer's coax-out tonight and see if the problem persists. Maybe it's just the Denon dvd's coax that's so sensitive to RFI.