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mrthreeplates
2005-05-18, 11:44
Hi,

I have my SB2 connected to a Classe DAC-1. Both the SB2 and the
DAC share a single power outlet (via a power strip). I have
noticed that when I turn on/off lights in my house that I
occasionally get glitches in the audio output. I have no idea
if these lights share the same circuit breaker or not. Let's
say for the sake of argument that they do.

I can see that the LOCK light on my DAC flickers when this
happens (which explains the glitches).

I have had similar problems when using my DAC while connected
to a M-audio sound card via the Coax input.

I don't have these problems when using the toslink input
on my DAC (with either the M-audio card or the SB2).

Now, my question for others: Do you have the same problem
when running with an exernal DAC/coax? Seems to me that
the issue is that the isn't enough electrical isolation
on either my DAC and/or SB2. I'm sure this is just something
I have to live with, but I'm wondering if I could fix
this somehow (like with a power conditioner of some sort...).

I'd like to use the coax output on the SB2 (as it is supposedly
superior to the toslink), but the glitches that I
get are a bit annoying.

Cheers,

George

kdf
2005-05-18, 11:57
what is your MAC address for your SB2?

seanadams
2005-05-18, 12:06
[flame suit on] Personally I find it unfortunate that S/PDIF was ever
specified to run over coax copper in the first place. There are some
who claim it's better than fiber for various reasons, but all
empirical data says that optical S/PDIF is FAR more reliable, works
over longer distances, and delivers measurably lower jitter at the
receiver. It also inherently isolates ground offset, low frequency
and EMI noise between devices. The only good reason to use coax is if
you don't have an optical cable or an optical input available, which
is primarily why we have the connector there. [/flame suit]

More constructively:

If you're having problems not just with Squeezebox2 but with other s/
pdif sources, then the problem could well be the cabling or your DAC.
Some things to check:

- try a different cable. Video cable may have higher bandwidth and
better shielding than those marketed as "digital interconnects", and
definitely will have the correct 75 ohm impedance.

- check your Squeezebox2 MAC address printed on the bottom. The first
SB2s produced had a bug in the coax output which could cause errors.
If your MAC is 00:04:20:05:A3:FA or lower, contact
support (AT) slimdevices (DOT) com for repair.

- If neither of those narrows down the problem, then it's probably a
defect in your DAC's input. I could help you troubleshoot but you'd
need an oscilloscope to see what's happening in there.

mrthreeplates
2005-05-18, 12:43
Thanks for the info. I checked my MAC address a while ago
and, as I recall, one of the leading digit fields was much
higher than the minimum specified earlier. It think it
started with a non-zero number, but I don't recall
exactly what it was at the moment.

As had problems with two differnent devices (SB2 and
the M-audio), I suspect it is my DAC that has issues
(or it's my house...).

I didn't mention, but have also tried two different
coax cables (same result).

In any case, I'm happy using TosLink for now. The fact that
the devices aren't eletrically connected (except via
the AC line) seems to me better anyway, but I could
be wrong. That was my solution when I used my M-audio card.

I haven't actually *heard* a difference between the coax/toslink,
but that could be a function of may equipment and/or ears...

Cheers,

George

Robin Bowes
2005-05-18, 14:44
Sean Adams wrote:
>
>
> [flame suit on] Personally I find it unfortunate that S/PDIF was ever
> specified to run over coax copper in the first place. There are some
> who claim it's better than fiber for various reasons, but all empirical
> data says that optical S/PDIF is FAR more reliable, works over longer
> distances, and delivers measurably lower jitter at the receiver. It
> also inherently isolates ground offset, low frequency and EMI noise
> between devices. The only good reason to use coax is if you don't have
> an optical cable or an optical input available, which is primarily why
> we have the connector there. [/flame suit]

Could you please take this to the Audiophile forum, or I'll have to
report you to Slim Devices?

:)

R.
--
http://robinbowes.com

JJZolx
2005-05-18, 15:09
I have had similar problems when using my DAC while connected
to a M-audio sound card via the Coax input.

I don't have these problems when using the toslink input
on my DAC (with either the M-audio card or the SB2).

Now, my question for others: Do you have the same problem
when running with an exernal DAC/coax? Seems to me that
the issue is that the isn't enough electrical isolation
on either my DAC and/or SB2. I'm sure this is just something
I have to live with, but I'm wondering if I could fix
this somehow (like with a power conditioner of some sort...).

I had the _exact_ same problem with an M-Audio Audiophile card when using the S/PDIF output to an external DAC. Switching a light on or some other power anomaly would invariably cause the DAC to lose sync. That was in my office sound system that I later downgraded and began using the S/PDIF out from the motherboard's onboard audio. I never had the problem again.

I think some devices are just more susceptible to power problems. My SB2 is connected to the same (Channel Islands) DAC now and running in my main audio system and I've yet to see the problem with the Squeezebox. Could be my home power is a lot more stable, though.
________
Honda VF400F (http://www.cyclechaos.com/wiki/Honda_VF400F)

Phillip Kerman
2005-05-18, 16:31
> [flame suit on] Personally I find it unfortunate that S/PDIF
> was ever
> specified to run over coax copper in the first place. There are some
> who claim it's better than fiber for various reasons, but all
> empirical data says that optical S/PDIF is FAR more reliable, works
> over longer distances, and delivers measurably lower jitter at the
> receiver. It also inherently isolates ground offset, low frequency
> and EMI noise between devices. The only good reason to use
> coax is if
> you don't have an optical cable or an optical input available, which
> is primarily why we have the connector there. [/flame suit]


Now I'm going to have to go test it. I wonder why everyone I've heard says
coax is better.

Thanks,
Phillip

mrthreeplates
2005-05-18, 19:01
To followup, my SB2 MAC address (as reported by
my wireless router) is 20:04:B9:00:00:0C .

I assume this qualifies as not being affected by
the problem with the early units.

Cheers,

George

seanadams
2005-05-18, 20:35
To followup, my SB2 MAC address (as reported by
my wireless router) is 20:04:B9:00:00:0C .


Huh? What's printed on the bottom of the Squeezebox2?

mrthreeplates
2005-05-18, 22:06
My mistake about the MAC address (too many devices
on my lan...). The number on the bottom is:

00:04:20:05:A2:B3

guess I'm one of the lucky ones after all :)

Cheers,

George

Stephen Glen Collier
2005-05-19, 00:55
> -----Original Message-----
> From: discuss-bounces (AT) lists (DOT) slimdevices.com
> [mailto:discuss-bounces (AT) lists (DOT) slimdevices.com] On Behalf Of
> mrthreeplates
> Sent: 18. mai 2005 20:44
> To: discuss (AT) lists (DOT) slimdevices.com
> Subject: [slim] coax digital output glitches w/AC power spikes
> ... Now, my question for others: Do you have the same problem
> when running with an exernal DAC/coax?...

FWIW, no I don't but ours is not a very electrically noisy household. Runs
into Linn Kinos high end processor.