The signal drops out randomly, but frequently throughout the day, for a second or less at a time. For example, simply plugging in an empty surge protected power strip into an adjacent wall outlet is enough for the SPDIF to kick out monetarily. Turning the power strip's switch on/off drops out the SPDIF also. Without anything connected to the strip which is plugged in to a separate outlet.
Any ideas what may cause this?
Any ideas what may cause this?
When you say the transport SPDIF drops out, do you mean the transport stops producing any SPDIF or the DAC mutes for a while? If the latter, what sort of cable are you using? You need an ordinary reasonable quality 75ohm coax, not some DIY or 'hi-end' rubbish - however expensive it was.
My initial guess is that ground-loop type noise is causing your problem. It's not perfectly clear from your description of the fault behavior whether or not it only occurs with that power strip plugged-in, but it sounds like it might be the causative element.
The easiest thing to try is to leave that power stip COMPLETELY disconnected from everything - put it away it in a box somewhere - and see if that solves the problem. If you instead simply leave the strip plugged in to a power outlet, even though it's switched off, it could still produce ground noise contamination via leakage. If the problem persists after removing the strip, it still may be ground-loop related but will be more difficult to pin down and resolve.
The easiest thing to try is to leave that power stip COMPLETELY disconnected from everything - put it away it in a box somewhere - and see if that solves the problem. If you instead simply leave the strip plugged in to a power outlet, even though it's switched off, it could still produce ground noise contamination via leakage. If the problem persists after removing the strip, it still may be ground-loop related but will be more difficult to pin down and resolve.
Sounds more like an EMC problem, some sort of spike on the power line... Do you have any kit to monitor the mains...
Also look what if any protection there is on the inputs of the CD transport and DAC...
AS Ken has said finding the problem could be problematic, but if it happens during the day I would suggest that something turning on and off could be causing the issue, see if you can correlate it to anything that switches in your home, fridges are on culprit, heating etc. another. Quite often these items switching on or off can cause a spike on the mains...
Good Luck
Also look what if any protection there is on the inputs of the CD transport and DAC...
AS Ken has said finding the problem could be problematic, but if it happens during the day I would suggest that something turning on and off could be causing the issue, see if you can correlate it to anything that switches in your home, fridges are on culprit, heating etc. another. Quite often these items switching on or off can cause a spike on the mains...
Good Luck
Hi ridikas,
marce has given good, solid advice as usual. What you can also try is a well filtered power strip to plug your sound equipment into. Something rated for RFI at least, and not a cheap power bar. Depending on severity, you may have to invest in an "on-line" UPS to solve these issues. Those are expensive, so try to track down the source as marce suggested first.
-Chris
marce has given good, solid advice as usual. What you can also try is a well filtered power strip to plug your sound equipment into. Something rated for RFI at least, and not a cheap power bar. Depending on severity, you may have to invest in an "on-line" UPS to solve these issues. Those are expensive, so try to track down the source as marce suggested first.
-Chris
Until he has answered my questions in post 2 we are all guessing.
Also, what sort of surge-protected power strip causes the problem: a normal commercial one for general use (with probably a filter and voltage limiter), or an 'audio' one with who knows what inside?
Also, what sort of surge-protected power strip causes the problem: a normal commercial one for general use (with probably a filter and voltage limiter), or an 'audio' one with who knows what inside?
Hi DF96,
It would be nice to know the answers from your questions in post #2, however they are not always easily known by the user. The further suggestions might be a more effective way for him to come to a solution.
-Chris
It would be nice to know the answers from your questions in post #2, however they are not always easily known by the user. The further suggestions might be a more effective way for him to come to a solution.
As you are well aware, each one comes filled with hopes and dreams. 🙂
-Chris
He may know what sort of cable he is using. If very cheap, or very expensive, or homemade, then it is the prime suspect. My guess is RF interference, sometimes from elsewhere and sometimes generated locally.
Hi DF96,
He has noticed that the dropout occurs with a disturbance on his AC mains. My suspicions therefore are in that direction. I'm not saying you're wrong at all, but the tie in with AC mains disturbances seems too strong to ignore.
I would hope he has tried a new cable in his troubleshooting up to this point in time.
-Chris
He has noticed that the dropout occurs with a disturbance on his AC mains. My suspicions therefore are in that direction. I'm not saying you're wrong at all, but the tie in with AC mains disturbances seems too strong to ignore.
I would hope he has tried a new cable in his troubleshooting up to this point in time.
-Chris
Plugging in an empty power strip, or flicking the switch on an empty power strip. should not disturb the mains. However, they may emit some RF especially if the strip has something peculiar such as a big cap across the mains.
His symptoms may be caused by a DIY or very expensive SPDIF cable (wide open to RF) combined with an audiophile power strip. If he tells us that he has nothing daft like that in his system then we can look for normal explanations, such as his house being wired by an incompetent electrician.
His symptoms may be caused by a DIY or very expensive SPDIF cable (wide open to RF) combined with an audiophile power strip. If he tells us that he has nothing daft like that in his system then we can look for normal explanations, such as his house being wired by an incompetent electrician.
Hi DF96,
Like that's never happened before!
Anyhow, agree on all points. I'm hoping he can dismiss the easy stuff though.
-Chris
Like that's never happened before!
Anyhow, agree on all points. I'm hoping he can dismiss the easy stuff though.
-Chris
FYI
light switch interference watching a pvr recording. - Technical - Digital Spy Forums
Central heating causing TV interference - TV and Home Entertainment Technology - Digital Spy Forums
https://www.energex.com.au/__data/assets/pdf_file/0020/31448/esaa_dealing_with_common_problems.pdf
There are many more instances of equipment switching on and off causing mains borne problems, HVAC being one of the main culprits. I spent 8 years working for a company called Deep Sea Electronics (they don't design what you may initially think) and learned a lot from the application engineers about how bad the mains can be, we also had the kit to record our own mains and see the problems. With digital if everything is just on the edge, these spikes can cause data drop outs etc. The UK EMC club magazine has a section called banana skins that has real life EMC stories, they are worth a read because some are unbelievable, often find similar things in there.
What makes me think it may be this is that other things cause the drop outs at different times during the day.
The problem is to find the cause as DF96 says we need all the pertinent information, a cable that is just on the edge signal integrity wise could be the cause, seen that before as well, where the signal was just getting through, but any external interference caused the signal to fall below acceptable levels and cause a data glitch.
The best one I saw though was the other way, a cable was made that was exactly 1/20th of the main data clocks wavelength, it lit up the EMC lab and caused major problems throughout the system...
light switch interference watching a pvr recording. - Technical - Digital Spy Forums
Central heating causing TV interference - TV and Home Entertainment Technology - Digital Spy Forums
https://www.energex.com.au/__data/assets/pdf_file/0020/31448/esaa_dealing_with_common_problems.pdf
There are many more instances of equipment switching on and off causing mains borne problems, HVAC being one of the main culprits. I spent 8 years working for a company called Deep Sea Electronics (they don't design what you may initially think) and learned a lot from the application engineers about how bad the mains can be, we also had the kit to record our own mains and see the problems. With digital if everything is just on the edge, these spikes can cause data drop outs etc. The UK EMC club magazine has a section called banana skins that has real life EMC stories, they are worth a read because some are unbelievable, often find similar things in there.
What makes me think it may be this is that other things cause the drop outs at different times during the day.
The problem is to find the cause as DF96 says we need all the pertinent information, a cable that is just on the edge signal integrity wise could be the cause, seen that before as well, where the signal was just getting through, but any external interference caused the signal to fall below acceptable levels and cause a data glitch.
The best one I saw though was the other way, a cable was made that was exactly 1/20th of the main data clocks wavelength, it lit up the EMC lab and caused major problems throughout the system...
Man am I glad to find this thread. This started happening to me lately. Esoteric p-700 skips when light switches are turned on. So I did a total re-cap. Transport sounds better than ever. But is more prone to problem. It's plugged into wall outlet not a strip. This happens across circuits.
DF96 was correct! I finally found my cheap digital cable to switch out my expensive one and that corrected the problem. The expensive cable sounded great. I don't understand it. No visual damage. Hope this helps someone.
Let me explain. Any expensive SPDIF cable must be based on one of two principles:mark adams said:
1. Ordinary commercial reasonable quality coax is not good enough for digital audio so you need some super-duper special quality coax.
2. Ordinary commercial reasonable quality coax is simply the wrong stuff for digital audio, so you really need special (handmade?) non-coax (twisted pair, plaited, unscreened etc?).
Both ideas are wrong, but idea 1 simply makes you spend more money than you need to. Idea 2 makes you spend more money for a vastly inferior cable, which picks up lots of interference and distorts the pulse shape. Fortunately, SPDIF is fairly robust so if you are lucky all that happens is that you have wasted your money. If you are unlucky you get dropouts too.
Note that an SPDIF cable cannot "sound great". This is simply impossible. Any competent coax cable will simply pass on the data with perfect data bits and sufficiently close to the correct timing that the PLL in the receiver will be happy and get rid of HF jitter caused by the cable. So an ordinary cable will 'sound perfect'; any change from this is either in your imagination, or is a degradation which you somehow misperceive as an improvement..
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