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View Full Version : Digital out fails for 64k audio, works for 56k



David Hearst
2004-07-09, 11:27
For quite awhile I've been using my Squeezebox and SlimServer to
deliver Live365 broadcasts to my stereo using the digital (optical)
output. It has worked fine for the stations I used up until now but it
turns out that all of them are being streamed at 56k bit quality from
their respective servers. Today I tried to set up a 64k bit stream in a
similar fashion and found that I get no output from my stereo. However,
if I use the analog outs on the Squeezebox they work fine. It's just
the digital (optical) output that is a problem. All the 64k stream
doesn't work, not only do 56k streams work, but the WAV audio files in
my iTunes library work fine as well when played through the digital
(optical) output.

Has anyone experienced this? Should the Squeezebox be delivering the
same type of digital signal output regardless of the stream rate
received by the SlimServer? Are there any settings I can change to
overcome this problem?

Thanks for the help,

David Hearst
david (AT) madd-dogg (DOT) com

seanadams
2004-07-09, 15:03
David,

Probably the stream is using a 32KHz sample rate, which is not
compatible with s/pdif (not a squeezebox limitation - just not
supported over s/pdif at all).

The best solution if you have a receiver which auto-senses the s/pdif
signal is to connect both cables. Then the amp will automatically fall
back to the analog inputs if s/pdif is not available.

Sean

On Jul 9, 2004, at 11:27 AM, David Hearst wrote:

> For quite awhile I've been using my Squeezebox and SlimServer to
> deliver Live365 broadcasts to my stereo using the digital (optical)
> output. It has worked fine for the stations I used up until now but it
> turns out that all of them are being streamed at 56k bit quality from
> their respective servers. Today I tried to set up a 64k bit stream in
> a similar fashion and found that I get no output from my stereo.
> However, if I use the analog outs on the Squeezebox they work fine.
> It's just the digital (optical) output that is a problem. All the 64k
> stream doesn't work, not only do 56k streams work, but the WAV audio
> files in my iTunes library work fine as well when played through the
> digital (optical) output.
>
> Has anyone experienced this? Should the Squeezebox be delivering the
> same type of digital signal output regardless of the stream rate
> received by the SlimServer? Are there any settings I can change to
> overcome this problem?
>
> Thanks for the help,
>
> David Hearst
> david (AT) madd-dogg (DOT) com
>
>

David Hearst
2004-07-09, 15:54
Sean,

Thanks for the suggestion. I've actually done a bit more
experimentation and it's pretty clear that the problem is not 32kHz
sample rate. Here's the additional info:

I own two Squeezeboxes (an early wireless model and a fairly recent
wired model). One is attached to the optical digital input on our home
theater receiver, the other is connected to an M-Audio Super DAC 2496.
After my original E-mail, I discovered that the Squeezebox /SuperDAC
combo was working fine with the 64k stream. I then confirmed that
either one of my Squeezeboxes work fine with the SuperDAC. They just
don't work with my home theater receiver.

To the best of my knowledge, the difference between these internet
radio stations is as follows:

Success: 56k bit , standard Live365 stream
Failure: 64k, MP3 Pro-capable Live365 stream

That leads me to a question. I'm just wondering whether you'd expect
the digital stream coming out of the Squeezebox to be significantly
different in these two cases and, if so, different in what way?
Obviously, a simple and not-too-expensive solution would be to purchase
another SuperDAC to use with our home theater. I'd just like to
understand what the problem is before jumping on that bandwagon...

Thanks, David


On Jul 9, 2004, at 3:03 PM, Sean Adams wrote:

>
> David,
>
> Probably the stream is using a 32KHz sample rate, which is not
> compatible with s/pdif (not a squeezebox limitation - just not
> supported over s/pdif at all).
>
> The best solution if you have a receiver which auto-senses the s/pdif
> signal is to connect both cables. Then the amp will automatically fall
> back to the analog inputs if s/pdif is not available.
>
> Sean
>
> On Jul 9, 2004, at 11:27 AM, David Hearst wrote:
>
>> For quite awhile I've been using my Squeezebox and SlimServer to
>> deliver Live365 broadcasts to my stereo using the digital (optical)
>> output. It has worked fine for the stations I used up until now but
>> it turns out that all of them are being streamed at 56k bit quality
>> from their respective servers. Today I tried to set up a 64k bit
>> stream in a similar fashion and found that I get no output from my
>> stereo. However, if I use the analog outs on the Squeezebox they work
>> fine. It's just the digital (optical) output that is a problem. All
>> the 64k stream doesn't work, not only do 56k streams work, but the
>> WAV audio files in my iTunes library work fine as well when played
>> through the digital (optical) output.
>>
>> Has anyone experienced this? Should the Squeezebox be delivering the
>> same type of digital signal output regardless of the stream rate
>> received by the SlimServer? Are there any settings I can change to
>> overcome this problem?
>>
>> Thanks for the help,
>>
>> David Hearst
>> david (AT) madd-dogg (DOT) com
>>
>>

dean
2004-07-13, 14:53
Can you post the URL for the failing station?

On Jul 9, 2004, at 3:54 PM, David Hearst wrote:

> Sean,
>
> Thanks for the suggestion. I've actually done a bit more
> experimentation and it's pretty clear that the problem is not 32kHz
> sample rate. Here's the additional info:
>
> I own two Squeezeboxes (an early wireless model and a fairly recent
> wired model). One is attached to the optical digital input on our home
> theater receiver, the other is connected to an M-Audio Super DAC 2496.
> After my original E-mail, I discovered that the Squeezebox /SuperDAC
> combo was working fine with the 64k stream. I then confirmed that
> either one of my Squeezeboxes work fine with the SuperDAC. They just
> don't work with my home theater receiver.
>
> To the best of my knowledge, the difference between these internet
> radio stations is as follows:
>
> Success: 56k bit , standard Live365 stream
> Failure: 64k, MP3 Pro-capable Live365 stream
>
> That leads me to a question. I'm just wondering whether you'd expect
> the digital stream coming out of the Squeezebox to be significantly
> different in these two cases and, if so, different in what way?
> Obviously, a simple and not-too-expensive solution would be to
> purchase another SuperDAC to use with our home theater. I'd just like
> to understand what the problem is before jumping on that bandwagon...
>
> Thanks, David
>
>
> On Jul 9, 2004, at 3:03 PM, Sean Adams wrote:
>
>>
>> David,
>>
>> Probably the stream is using a 32KHz sample rate, which is not
>> compatible with s/pdif (not a squeezebox limitation - just not
>> supported over s/pdif at all).
>>
>> The best solution if you have a receiver which auto-senses the s/pdif
>> signal is to connect both cables. Then the amp will automatically
>> fall back to the analog inputs if s/pdif is not available.
>>
>> Sean
>>
>> On Jul 9, 2004, at 11:27 AM, David Hearst wrote:
>>
>>> For quite awhile I've been using my Squeezebox and SlimServer to
>>> deliver Live365 broadcasts to my stereo using the digital (optical)
>>> output. It has worked fine for the stations I used up until now but
>>> it turns out that all of them are being streamed at 56k bit quality
>>> from their respective servers. Today I tried to set up a 64k bit
>>> stream in a similar fashion and found that I get no output from my
>>> stereo. However, if I use the analog outs on the Squeezebox they
>>> work fine. It's just the digital (optical) output that is a problem.
>>> All the 64k stream doesn't work, not only do 56k streams work, but
>>> the WAV audio files in my iTunes library work fine as well when
>>> played through the digital (optical) output.
>>>
>>> Has anyone experienced this? Should the Squeezebox be delivering the
>>> same type of digital signal output regardless of the stream rate
>>> received by the SlimServer? Are there any settings I can change to
>>> overcome this problem?
>>>
>>> Thanks for the help,
>>>
>>> David Hearst
>>> david (AT) madd-dogg (DOT) com
>>>
>>>