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View Full Version : Burst of white noise on startup?



Mark Lanctot
2006-01-09, 15:33
Almost all the time (but not every single time) I
get a very loud burst of white noise on startup.
This is when the player is brought out of standby
to a playing state.

I suspect it's the same maximum-volume white noise
discussed here:

http://forums.slimdevices.com/showthread.php?t=19309

These bursts are short, less than 1/4 of a second,
but they really make you jump - it's like a gunshot.

At first I thought it was only MP3s, then only
SqueezeNetwork, but it is FLACs also.

It's not every startup, more like 75% of startups.

I put in a 0.25 second delay in audio start-up
time, thinking it was my receiver's DACs, but
there was no change. Perhaps I should set it to
0.5 seconds.

Setup details:

SB2, SB3 (both players exhibit the problem)
SlimServer 6.2.2, 01-03-06 nightly build
Windows XP SP2
Marantz 8400 receiver connected via optical

It's not a terribly important issue to me but if
it's related to the much-more serious bug
referenced above I'm wondering if my experience
will help developers track down the bug. My minor
issue is much more reproducible than the more
serious one, but not 100% reproducible.

It doesn't seem totally related to that bug but
I'm guessing the same failure that's happening
with this bug is happening to me on startup only.

Does anyone else notice this? Would adding my
experience to that bug help things, or is it
unrelated?

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Mark Lanctot
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dean
2006-01-10, 14:44
Do you hear the noise if you listen to the analog or headphone
outputs on the Squeezebox?

Mark Lanctot
2006-01-10, 16:59
I haven't tried that. I'll try it tonight.

Thanks Dean.

dean blackketter wrote:
> Do you hear the noise if you listen to the analog or
headphone outputs
> on the Squeezebox?
>
>
>

Mark Lanctot
2006-01-10, 17:31
I tried it about 10 times using the headphone output. No bursts.

As if on cue, when I switched back to digital, I got a burst right away.

So I guess it's caused by my receiver DAC not having enough time to initialize? I'll change the delay to 0.5 seconds.

mftech
2006-01-10, 21:56
Do you hear the noise if you listen to the analog or headphone
outputs on the Squeezebox?

Hi Sean,
I got a similar problem but in my case the problem occur suddently and randomly and the white noise stay on.
The noise is not steady and got some interuption to it.
It's very annoying specialy when you listen with loud volume.

I must turn off my DAC to get rid of the problem.
I could confirm that the problem doesn't occur at the headphone output.


Here's my setup:
SB3 Spdif out>Canare 75@100>Merging Sphinx DAC AES IN>Sphinx AES Out>Behringer DCX2496 AES In.
I'm going trought the Sphinx to reference my signal via wordclock or a video reference.
The Sphinx is set to 44.1Khz

You could also refer to this thread:

http://forums.slimdevices.com/showthread.php?t=19309&page=3&highlight=white+noise

Regards
Michel

mattg
2006-01-30, 09:58
Could it be that the receiver is expecting something other than PCM (say, Dolby Digital)? Some receivers mute themselves until they figure out how the stream is encoded (so you miss the first second or so of sound), but I have seen others that don't mute. If the receiver doesn't self mute and it's not getting the stream it expects it's going to sound ugly until it figures it out.

Mark Lanctot
2006-01-30, 11:21
I never thought of that, good point.

Unfortunately I don't think this is happening. My
receiver remembers the last decoding setting I had
on a particular input. On that input I never
choose Dolby Digital decoding, and you can't even
activate DD decoding unless it's actually
receiving a DD stream.

I usually have multichannel stereo decoding on
that input, and when I switch to it with the SB
off, that's the decoding format the receiver
remembers. And note that I usually turn on the
receiver first, switch to that input (which goes
into multichannel stereo and expects to receive
PCM according to the display) and then turn on the SB.

There has never been a DD stream on that input for
the life of the receiver.

As well, my DVD player input does not behave like
this. And the receiver does seem to mute the
sound until the decoder switches.

mattg wrote:
> Could it be that the receiver is expecting something
other than PCM
> (say, Dolby Digital)? Some receivers mute
themselves until they figure
> out how the stream is encoded (so you miss the first
second or so of
> sound), but I have seen others that don't mute. If
the receiver
> doesn't self mute and it's not getting the stream it
expects it's going
> to sound ugly until it figures it out.
>
>

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Mark Lanctot
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