How do I stop volt spikes from switching?

[N.O.Y.B.]

Hi,

I have a Yamaha RX-V450 amplifier and it's plugged into what is supposed to
be a good quality surge protection power-board (a Belkin brand board with 10
sockets - the first 4 of the outlets are protected the remaining 6 are not,
but I made sure I plugged the amplifier into one of the protected sockets).
Now, this is where things are funny - I believe this board is supposed to
protect against voltage spikes.

My amplifier/reciever has digital input (PCM/Wave SPDIF/OUT) from the
high-quality (M-Audio Delta 2496) soundcard installed in my PC. I use
standard PCM input (digital wave-out).

When I'm playing audio the PCM indicator is on which indicates that digital
audio/wave is coming through as it should.

When I switch lights on/off the PCM signal is dropped for about a second and
then comes back, when this happens the PCM indictator on my amplifier goes
off and then comes back on to indicate the dropped signal. The same thing
happens when my refrigerator's thermostat switches on/off or when I use my
foot massager (which has an electric motor).

I suspect voltage spikes which may (or may not) be harmless - but it is
definately caused by switching. Is there anything I can do to prevent this
from happening in the future as I am concerned about the possibility of the
glitches causing serious damage to my amplifier and PC/soundcard hardware.

Worried,
Ben

 

[Phil Allison]

"N.O.Y.B."

Hi,

I have a Yamaha RX-V450 amplifier and it's plugged into what is supposed to
be a good quality surge protection power-board (a Belkin brand board with 10
sockets - the first 4 of the outlets are protected the remaining 6 are not,
but I made sure I plugged the amplifier into one of the protected sockets).
Now, this is where things are funny - I believe this board is supposed to
protect against voltage spikes.

My amplifier/reciever has digital input (PCM/Wave SPDIF/OUT) from the
high-quality (M-Audio Delta 2496) soundcard installed in my PC. I use
standard PCM input (digital wave-out).

When I'm playing audio the PCM indicator is on which indicates that digital
audio/wave is coming through as it should.

When I switch lights on/off the PCM signal is dropped for about a second and
then comes back, when this happens the PCM indictator on my amplifier goes
off and then comes back on to indicate the dropped signal. The same thing
happens when my refrigerator's thermostat switches on/off or when I use my
foot massager (which has an electric motor).

I suspect voltage spikes which may (or may not) be harmless - but it is
definately caused by switching. Is there anything I can do to prevent this
from happening in the future as I am concerned about the possibility of the
glitches causing serious damage to my amplifier and PC/soundcard hardware.

Worried,

** Dear Worried,

the PCM signal interruption you are having is very liekly due to RFI (
Radio Frequency Interference) - not AC supply spikes. The RF energy is due
to sparks that exists just as the particular switch opens in each case you
have described. If you have an AM radio, tuned to a blank spot on the dial,
you will hear loud cracks at these same times.

The RF energy may be injected to the PCM input through the air *or* via the
AC ground wiring *or* even as an accidental result of suppression caps
inside various items of gear.

I think you have just discovered, again, why optical data links are so
popular.




............ regards, Uncle Phil

 

[N.O.Y.B.]

It turns out you are correct.

I did it with radio and get "clap" noise when I switch things on and off.

You're right about the optical data links, this coaxial doesn't have any
shielding and besides, optical links produce a cleaner bass and treble.

noyb

 

[N.O.Y.B.]

Right, I know what is happening, so now I can focus on what to do about it.

Is there anything I can do to actually help eliminate that interference?
What sort of filters can I buy?

noyb

 

[Phil Allison]

"N.O.Y.B."

It turns out you are correct.

** Yawn.

I did it with radio and get "clap" noise when I switch things on and off.

** No fooling.

You're right about the optical data links, this coaxial doesn't have any
shielding

** Huh ????????????



and besides, optical links produce a cleaner bass and treble.

** Yawn.


..... Uncle Phil

 

[Phil Allison]

"N.O.Y.B."

Right, I know what is happening, so now I can focus on what to do about it.

** That is one of the best remarks ever seen on this NG.

No problem can be rationally solved until you KNOW the cause.

Is there anything I can do to actually help eliminate that interference?

** Yep - put a suppressor cap on very switch in the NEIGHBOURHOOD.

What sort of filters can I buy?

** Spark suppression requires individual attention to each source - ie
EVERY - DAMN - SWITCH !!!

Not just in your house - but all the neighbours too.

Impractical.

Use well shielded co-ax cable or GO optical.

WTF were you using ????




.............. Uncle Phil

 

[N.O.Y.B.]

Standard digital coax cable for audio applications. I might have to get a
better quality cable.

Impossible to go optical - my m-audio soundcard does not have an optical
digital out, only a coaxial one ;-)

noyb

 

[Phil Allison]

"N.O.Y.B."

Standard digital coax cable for audio applications.

" ... this coaxial doesn't have any
shielding .. "


** Please explain ????????????



....... Uncle Phil

 

[David Sauer]

and besides, optical links produce a cleaner bass and treble.

And shielded optical is even better.

 

[Phil Allison]

** I did not write this.

And shielded optical is even better.

** Lead, concrete, steel, mu-metal ???

Or maybe " UV - ray " shielded ?

To protect one's dear old mum.

Since Sauer never had a dad.




............ Phil

 

[eltan]

replace your sound card to the one with an optical out. eg SoundBlaster

 

[N.O.Y.B.]

My cable probably does have sheilding but I guess it's only minimal
sheilding to protect it from most interference, but certainly not all. If I
get cable that has better shielding it might help but I doubt it would solve
the entire problem unless as you say I put caps on every potential source to
eliminate RF noise.

noyb

 

[Brian Goldsmith]

and besides, optical links produce a cleaner bass and treble.

And shielded optical is even better.

***** Technically, what a silly stupid thing to write,the mind boggles!!!!

Brian Goldsmith

 

[Alex]

My cable probably does have sheilding but I guess it's only minimal
sheilding to protect it from most interference, but certainly not all. If I

Coaxial cable, by definition, has an outer shield.
The outer shield is also used as a signal ground.

get cable that has better shielding it might help but I doubt it would solve
the entire problem unless as you say I put caps on every potential source to
eliminate RF noise.

You can get converters from Jaycar which go from coaxial (RF) SPDIF to
TOSLINK (optical), for $40:

http://www1.jaycar.com.au/productView.asp?ID=AA1722&CATID=15&SUBCATID=459

(if the link doesn't work, do a search on www.jaycar.com.au for
"toslink")

Perhaps a short coaxial cable to one of these converters, and then the
rest of the run as toslink?

Good on you putting up with Phil.

Cheers,
Alex.

 

[Phil Allison]

"Alex" <[email protected]>



** Lisa - Alex - Ernie ????

Ménage a trios ?




......... Phil

 

[N.O.Y.B.]

You can get converters from Jaycar which go from coaxial (RF) SPDIF to

TOSLINK (optical), for $40:

http://www1.jaycar.com.au/productView.asp?ID=AA1722&CATID=15&SUBCATID=459

(if the link doesn't work, do a search on www.jaycar.com.au for
"toslink")

Perhaps a short coaxial cable to one of these converters, and then the
rest of the run as toslink?

I doubt it would cut out the interference, maybe a very small amount of it.
The distance between my PC's soundcard and my digital amplifier is about
45cm, they are both on the same desk. You still have a coaxial connection
and it is the coaxial connection, as well as the coax cable, that will get
hit by RF interference. I doubt changing the path with this adapter would
solve the problem, it might, but I have doubts, I still need to use the
coaxial output which means that coaxial signal must come out of the
soundcard, which means that interference can strike it anywhere along that
pathway between the break-out cable and the adapter. My PC soundcard is an
m-audio that has a break-out cable and the coaxial output is an off-shoot of
the break-out cable. So chances are, even if I install this adapter, the
interference will still hit my audio.

Good advice though, I've had a look at the adapter, and it's going for $20
now, so right now it's a bargain.

noyb

 

[Alex]

** Lisa - Alex - Ernie ????

Ménage a trios ?

Is that the best you can do?

Cheers,
Alex.

 

[Alex]

The distance between my PC's soundcard and my digital amplifier is about
45cm, they are both on the same desk.

Ah. I had assumed a longer run.

Have you tried a powerboard with surge supression built in?

the break-out cable. So chances are, even if I install this adapter, the
interference will still hit my audio.

Indeed.
Nice cards though, I've often considered getting one for myself.

Cheers,
Alex.

 

[N.O.Y.B.]

Have you tried a powerboard with surge supression built in?

Yup. As stated above in this thread I mentioned I use one. It's one of the
good Belkin models, it's black and it has 10 sockets, 4 of which are
protected, my computer and my amplifier are both plugged into protected
sockets. No difference. It still happens. I guess the RFI is "injected" into
the air by simple things like switching on lights, by thermostats, and by
motors. Sometimes it goes into the electrical connection, which is just as
likely, but I doubt surge supression board is going to stop the RFI.

My Belkin board may have lost it's spike suppression ability (they quite
often do so I've been told), but I doubt it, and besides, there's no way to
really know if it has and I'm not about to spend another $159 to find out.

The "spikes" are not really spikes at all but rather RFI crackling, which is
harmful to the digital signal of course but completely harmless to the
Yamaha reciever.

noyb

 

[Phil Allison]

"Alex"
"Phil Allison"

Is that the best you can do?

** Maybe they are all you - in various get ups.




.......... Phil