Airport Express BUZZZZZZZZZZZ
Nov 17, 2008 at 11:11 AM Thread Starter Post #1 of 33

johnwmclean

Aka: capone, bignurse.
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I bought a new airport express last week, I returned it under warranty as I was occasionally getting a squelching buzzing sound which oscillates with music (very very unpleasant)
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Buzzing is still there with a new airport express... I though maybe interference, but have ruled that out. I can be happily listening to a couple of songs then whaamo it’s there, I stop itunes, and then continue and that fixes it temporarily. Also pulling the toslink cable in and out quickly fixes it also.
Computer is a iMac G5 (not intel) Airport is connected with a mini to toslink to my 840c, all connections are tight. Does anybody have any ideas?
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Nov 17, 2008 at 2:20 PM Post #2 of 33
try connecting an analog 1/8" cable to the airport express to see if the buzzing is still there.

It is odd though - toslink out bypasses the AEx's dac. Hopefully the DAC in your 840c isn't about to give up the ghost. Do you have another toslink source to feed the dac to test?
 
Nov 17, 2008 at 3:39 PM Post #4 of 33
Quote:

Originally Posted by grawk /img/forum/go_quote.gif
Does the imac have optical out? If so, try using it instead of the airport and see if the problem is still there.


he is using the TOSlink out which is optical.

I have a Macbook and use the same TOSlink with no problem whatsoever in regards to interference with my built in Airport Extreme. I have had interference problems on wifi sometimes with audio going through my sound card but audio over optical fiber should be affected by the EMI. Perhaps the audio signal in your machine is being affected by the EMI from the Airport Express card even before it goes out over the optical fiber.
 
Nov 17, 2008 at 3:48 PM Post #5 of 33
I'm aware he's using the optical out on the airport. I'm suggesting using the optical out on the imac (if it has one) as a way of isolating where the problem is.
 
Nov 17, 2008 at 4:25 PM Post #6 of 33
With 2 A.E doing the same thing i would suspect other gear as having
the problem and one I have not expierenced with my 2yr old A.E.or anyone elses but i have heard bad static on my Sony and its dac turned
out to be bad and it was time for an upgrade anyway so it was rplaced
with an Onkyo.
 
Nov 17, 2008 at 4:33 PM Post #8 of 33
Yeah, since he experience the same with two different AirPort Express' I think the problem lay elsewhere as well.
Hooking the DAC directly up to the iMac, to hear if the same BUZZZZZZZ'ing occur would be the first step. Then try the analog out of the AirPort Express as next step.
 
Nov 17, 2008 at 7:00 PM Post #9 of 33
The optical out on the mac is dead, hence the reason I bought the airport express. I think the dac in the 840c is functioning well as it plays cds perfectly so I really don't think it would be that, I've also tried the two inputs as well. The cable is 10 metres in length (my mistake should have been 10 foot, I ordered the wrong size), is this an issue? Maybe it's the cable...
By the way... Big thanks to all you helpful head-fiers!
 
Nov 17, 2008 at 7:03 PM Post #10 of 33
An optical cable shouldn't cause buzzing, it could cause dropouts or other effects, but buzzing is generally an electrical problem.
 
Nov 17, 2008 at 7:40 PM Post #12 of 33
could be, that's what I was wanting to test by having you use the mac
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Do you have anything else with an optical out? dvd player, etc?
 
Nov 18, 2008 at 8:20 AM Post #13 of 33
I haven't the right cable to test with my DVD Player, I've contacted CA technical support as well as my dealer to try and resolve this problem. From doing extensive searches on the Internet there is nothing related to the 840c having this problem or fault, so fingers crossed it's something less sinister. I believe and hope the problem lies with the cable, a fault with manufacturing or maybe a kink? I will do some more tests tonight to see what I find.
 
Nov 18, 2008 at 10:31 AM Post #14 of 33
It could be the cable (unlikely, but possible). Hard to know the sound of the buzz you are hearing, but it could be caused by a damaged optical cable - either damage at one of the connecting ends or within the optics of the strand itself. If there is a breakage the signal could be distorted. As I mentioned, this is unlikely to manifest itself in this way, but possible. It is also the cheapest thing in your system to test - just buy a cheap nasty optical cable to test with (even a cheap one should provide a decent test).

Meant to add that it doesn't take much to damage an optical cable - especially a higher quality one with glass optics
 
Nov 18, 2008 at 10:57 AM Post #15 of 33
Tried again, the first track I played was ok for about a minute then there’s a loud digital squeelch for a couple of secs, then all is well for say five tracks at least 15 minutes of good listening. I change to a couple of other tracks another 4 more minutes of good listening then it appears softer but says for about 20 secs and goes away again. It appeared a couple more times I changed the dither setting on the 840c to on and this stopped one of the longer episodes, but appeared again
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. An interesting observation is that if I leave it playing it can probably get through a whole album. As soon as I stop and start itunes it seems to trip it up.
 

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