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Fifer
2005-11-09, 04:49
I'm not sure if this is a general problem or if the electrics in my house are unusually noisy, but I occasionally suffer 'drop-outs' when switching lights on or off, if an outside PIR controlled light comes on, from the central heating controller and various other mains powered equipment. The effect is just a momentary loss of sound. I'm wondering why the effect is instantaneous? If the data stream is being interrupted by mains-borne or (more likely, I suspect) RF interference, shouldn't the data already in the buffer cover the gap?

It's not a big problem but I am curious about this effect and also any potential solutions?

seanadams
2005-11-09, 05:48
I'm not sure if this is a general problem or if the electrics in my house are unusually noisy, but I occasionally suffer 'drop-outs' when switching lights on or off, if an outside PIR controlled light comes on, from the central heating controller and various other mains powered equipment. The effect is just a momentary loss of sound. I'm wondering why the effect is instantaneous? If the data stream is being interrupted by mains-borne or (more likely, I suspect) RF interference, shouldn't the data already in the buffer cover the gap?

It's not a big problem but I am curious about this effect and also any potential solutions?

I assume you're using coax digital, right?
What kind of receiver?
How long is the drop?

I've heard of this sort of thing with s/pdif equipment before, but this is the first time anyone's seen it with a squeezebox setup. I think what happens is there's a strong enough electrical transient in the house as to cause a small spike to go across the s/pdif cable - at that moment the receiver loses sync with the data and it takes a second or so to lock on to the stream again. So it's not RF and it's not a buffer underrun. Some things to try:

- put squeezebox and the receiver on the same power strip
- try a different s/pdif cable
- try optical instead of coax

Fifer
2005-11-09, 06:12
Sorry Sean, I should have been more specific. My set-up is fairly simple: a wireless SB2 with the analogue output feeding a headphone amp via a 3 metre phono cable and the digital coax feeding into my (slightly long in the tooth) Pioneer NSDV-55 receiver via a short (1 metre approx) cable.

I couldn't swear to it right now, but I'm pretty ceratin that digital and analogue ouputs are affected. (Digital for certain).

EDIT: Just re-read the last part of your post and I'm wondering if my laziness has contributed to the problem. I do all my 'serious' listening through the analogue output and headphone amp and just quickly rigged up the digital connection for background music using one half of a stereo phono cable I had lying around. Could the unconnected half be acting as an aerial and inducing the spike in the other half carrying the digital signal?

seanadams
2005-11-09, 07:42
just quickly rigged up the digital connection for background music using one half of a stereo phono cable I had lying around.

Bingo - stereo rca cables are no good for s/pdif. You need a good quality 75 ohm cable (video cable works great).


Could the unconnected half be acting as an aerial and inducing the spike in the other half carrying the digital signal?

No - it's just not the right cable. It's the wrong impedance and not sufficiently shielded to carry the high frequency s/pdif signal.

Fifer
2005-11-09, 08:13
Thanks, I'll change it.