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View Full Version : kinks in the SB2?



Phillip Kerman
2005-03-29, 19:35
Happy to say I got my SB2... it looks cool and sounds great... but I think
there are a few kinks to work out.

First, mine goes blank for no apparent reason sometimes. Blank screen.

Also, I'm trying to compare the digital out into my DAC to the internal DAC
but the digital out can't stay locked (I think that's it... my receiver
keeps reseting like it used to between PCM and MP3).

Plus, it won't connect to my wireless network--though the tech support seems
to think it's my access point.

I'm open to other ideas--I want it to work. I just don't know
if I'm in the mood to work through a ton of troubleshooting.

Thanks,
Phillip

seanadams
2005-03-29, 19:49
> First, mine goes blank for no apparent reason sometimes. Blank screen.

Does it keep playing audio? Can you control it from the web interface?

> Also, I'm trying to compare the digital out into my DAC to the
> internal DAC
> but the digital out can't stay locked (I think that's it... my receiver
> keeps reseting like it used to between PCM and MP3).

That shouldn't be. Which receiver?

> Plus, it won't connect to my wireless network--though the tech support
> seems
> to think it's my access point.

Which access point? We tested numerous configs with several dozen
access points. So far we've had only one issue that I know of, with a
specific recent hardware rev of the Linksys BEFW11S4 - we're looking
into it.

seanadams
2005-03-30, 08:35
>
> First, mine goes blank for no apparent reason sometimes. Blank screen.
>

Some new information suggests that this might be triggered when the
server is stopped and then restarted (ie something to do with the
reconnection logic on the client). Does that jibe?

Phil Karn
2005-03-30, 18:53
Phillip Kerman wrote:

> First, mine goes blank for no apparent reason sometimes. Blank screen.

I see that too. I don't think the unit actually crashes, but it can be
disconcerting.

> Also, I'm trying to compare the digital out into my DAC to the internal DAC
> but the digital out can't stay locked (I think that's it... my receiver
> keeps reseting like it used to between PCM and MP3).

I wonder if this is could be related to the "crunchy distortion" I
reported last night with my own SB2. I can't confirm it, but it very
definitely sounds like the firmware in the box is starving the DAC when
it has to handle the sustained, high speed burst of incoming traffic
that fills up the playback buffer with raw PCM data. If the DAC is
indeed being intermittently starved, perhaps this is killing the clock
on the S/P-DIF output and making it difficult for your external DAC to
maintain lock.

Does the problem happen on all files, or only those transcoded to raw,
high speed PCM? And does it persist through the entire track, or does it
only happen at the beginning? The "crunchy distortion" I notice on my
SB2 only occurs on raw, high speed PCM, and only until the buffer
fills. When that happens and the server backs off to its "maintenance"
speed of about 1.4 megabits/sec, the distortion goes away.

It just occurred to me that I could try forcing the Ethernet down to 10
megabits/sec and see if the problem still occurs. If it's indeed due to
DAC starvation from lack of proper CPU real-time management, this might
work around the problem by limiting the peak speed of the buffer-fill
burst to only 10 Mb/s.

--Phil

Robin Bowes
2005-03-31, 15:09
Phil Karn wrote:
> It just occurred to me that I could try forcing the Ethernet down to 10
> megabits/sec and see if the problem still occurs. If it's indeed due to
> DAC starvation from lack of proper CPU real-time management, this might
> work around the problem by limiting the peak speed of the buffer-fill
> burst to only 10 Mb/s.

Phil,

I believe the wired link on the SB is only 10MB/s anyway.

R.
--
http://robinbowes.com