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Spectral view of AC

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Anonymous
April 21, 2005 12:21:47 PM

Archived from groups: rec.audio.pro (More info?)

Hi,

I was wondering if anyone could tell me if it's possible to view a
detailed waveform of the AC coming from my walls. I've seen pictures
taken from oscilloscopes, so I think it's possbile. Does anyone know
the procedure? Are there any other ways to perform this analysis
without an oscilloscope?

Appreciate your input,

Harry

More about : spectral view

April 21, 2005 12:21:48 PM

Archived from groups: rec.audio.pro (More info?)

If want to see a "waveform" you need a scope.

Did you want to see a waveform or a spectral view, they are not the
same thing.

Why do you want to see this anyway?

Mark
April 21, 2005 12:21:48 PM

Archived from groups: rec.audio.pro (More info?)

you hear the crackling and clicks even when there is no audio playing
through the pre-amps?
that would not be non-linear distortion but ok...

or do you hear clicks only at the loudest peaks of the audio? that
would not likley be a power line problem (unless your line voltage was
very low but then you lights would be dim etc)


connect a line powered AM radio. If you hear the same crackles and
clicks you MAY have some line noise. But a good pre with correct
wiring should reject that stuff anyway. If everything has just been
re-wired in the new studio, I would troubleshoot the wiring. Connect a
mic directly to the pre and see what happens.

Mark




Mark
Related resources
Anonymous
April 21, 2005 2:45:44 PM

Archived from groups: rec.audio.pro (More info?)

Mark,

I've recently changed studio locations, and I'm having problems with
non-linear distortion in all of my preamps. I can even hear
intermittant crackling and clicks coming from my speakers. I suspect
the AC in my new location is the culprit, but I would like to be sure
before investing in Power Regeneration units - very pricey.

Spectral and waveform views would be helpful.


On 21 Apr 2005 06:35:13 -0700, "Mark" <makolber@yahoo.com> wrote:

>If want to see a "waveform" you need a scope.
>
>Did you want to see a waveform or a spectral view, they are not the
>same thing.
>
>Why do you want to see this anyway?
>
>Mark
Anonymous
April 21, 2005 2:59:16 PM

Archived from groups: rec.audio.pro (More info?)

Harry Houdini <harry@houdini.com> wrote:
>
>I've recently changed studio locations, and I'm having problems with
>non-linear distortion in all of my preamps. I can even hear
>intermittant crackling and clicks coming from my speakers. I suspect
>the AC in my new location is the culprit, but I would like to be sure
>before investing in Power Regeneration units - very pricey.
>
>Spectral and waveform views would be helpful.

Rent a power line analyzer. Fluke makes a nice one, and Tucker
will probably have one in rental stock. It will tell you a lot more
than just a momentary waveform will, because it will watch the line
for days on end and flag anything unusual.
--scott

--
"C'est un Nagra. C'est suisse, et tres, tres precis."
Anonymous
April 21, 2005 4:04:11 PM

Archived from groups: rec.audio.pro (More info?)

Mark,

Thanks for your help.

In answer to your questions:

- the noise from the preamps only occurs during recording. If I loop a
generator signal (sine, pink noise etc) through any premap and watch
the results in a software-based analyzer, I see pronounced peaks at
60Hz + related harmonics and there is a lot fluctuation at those
frequencies.

- the noise coming from my speakers, an intermittant crackle + AC hum,
happens when no audio is going through them (preamp and amp are just
on). When I do play audio, I hear a loud click/pop every once in a
while. This noise is definitely not in the source material being
played. It have unplugged all inputs to the preamp, leaving only its
connection to the power amp, amp to speakers. The background hash and
crackling is still there.

Evidently I have a ground issue + extremely dirty AC, but I'm at wit's
end trying to get rid of it. I have a 20amp balanced power transformer
which is on its own circuit. It worked fine in my previous location.
Everything plugs into it, so I am not creating loops by running gear
from different outlets.

I have tried star-grounding the power distribution unit - i.e.,
running a wire from the chasis of the unit to the building's ground
wires. No change.

Any suggestions for cleaning up the AC? Is my only option a
regenerator?






On 21 Apr 2005 07:57:20 -0700, "Mark" <makolber@yahoo.com> wrote:

>you hear the crackling and clicks even when there is no audio playing
>through the pre-amps?
>that would not be non-linear distortion but ok...
>
>or do you hear clicks only at the loudest peaks of the audio? that
>would not likley be a power line problem (unless your line voltage was
>very low but then you lights would be dim etc)
>
>
>connect a line powered AM radio. If you hear the same crackles and
>clicks you MAY have some line noise. But a good pre with correct
>wiring should reject that stuff anyway. If everything has just been
>re-wired in the new studio, I would troubleshoot the wiring. Connect a
>mic directly to the pre and see what happens.
>
>Mark
>
>
>
>
>Mark
Anonymous
April 21, 2005 4:05:45 PM

Archived from groups: rec.audio.pro (More info?)

Scott,

Once again, you prove to be one of this forum's greatest assets.
Thanks for your help.

I will look into this analyzer you suggested.

Harry


On 21 Apr 2005 10:59:16 -0400, kludge@panix.com (Scott Dorsey) wrote:

>Harry Houdini <harry@houdini.com> wrote:
>>
>>I've recently changed studio locations, and I'm having problems with
>>non-linear distortion in all of my preamps. I can even hear
>>intermittant crackling and clicks coming from my speakers. I suspect
>>the AC in my new location is the culprit, but I would like to be sure
>>before investing in Power Regeneration units - very pricey.
>>
>>Spectral and waveform views would be helpful.
>
>Rent a power line analyzer. Fluke makes a nice one, and Tucker
>will probably have one in rental stock. It will tell you a lot more
>than just a momentary waveform will, because it will watch the line
>for days on end and flag anything unusual.
>--scott
Anonymous
April 21, 2005 4:27:55 PM

Archived from groups: rec.audio.pro (More info?)

Harry Houdini <harry@houdini.com> wrote:
>
>- the noise from the preamps only occurs during recording. If I loop a
>generator signal (sine, pink noise etc) through any premap and watch
>the results in a software-based analyzer, I see pronounced peaks at
>60Hz + related harmonics and there is a lot fluctuation at those
>frequencies.

So have you looked for groound loops?

>- the noise coming from my speakers, an intermittant crackle + AC hum,
>happens when no audio is going through them (preamp and amp are just
>on). When I do play audio, I hear a loud click/pop every once in a
>while. This noise is definitely not in the source material being
>played. It have unplugged all inputs to the preamp, leaving only its
>connection to the power amp, amp to speakers. The background hash and
>crackling is still there.

Could be a grounding issue, could be RF trash.

>Evidently I have a ground issue + extremely dirty AC, but I'm at wit's
>end trying to get rid of it. I have a 20amp balanced power transformer
>which is on its own circuit. It worked fine in my previous location.
>Everything plugs into it, so I am not creating loops by running gear
>from different outlets.

Running gear from different outlets does not create loops, it just makes
existing loops bigger. A proper ground scheme prevents that from ever
being a problem.

>I have tried star-grounding the power distribution unit - i.e.,
>running a wire from the chasis of the unit to the building's ground
>wires. No change.

Ground loops are caused by TOO MANY ground paths. Adding more makes
the problem worse.

>Any suggestions for cleaning up the AC? Is my only option a
>regenerator?

What is a regenerator? Do you mean an M-G set?
--scott
--
"C'est un Nagra. C'est suisse, et tres, tres precis."
Anonymous
April 21, 2005 4:32:23 PM

Archived from groups: rec.audio.pro (More info?)

Harry Houdini wrote:
> Mark,
>
> Thanks for your help.
>
> In answer to your questions:
>
> - the noise from the preamps only occurs during recording. If I loop
a
> generator signal (sine, pink noise etc) through any premap and watch
> the results in a software-based analyzer, I see pronounced peaks at
> 60Hz + related harmonics and there is a lot fluctuation at those
> frequencies.
>
> - the noise coming from my speakers, an intermittant crackle + AC
hum,
> happens when no audio is going through them (preamp and amp are just
> on). When I do play audio, I hear a loud click/pop every once in a
> while. This noise is definitely not in the source material being
> played. It have unplugged all inputs to the preamp, leaving only its
> connection to the power amp, amp to speakers. The background hash and
> crackling is still there.
>
> Evidently I have a ground issue + extremely dirty AC, but I'm at
wit's
> end trying to get rid of it. I have a 20amp balanced power
transformer
> which is on its own circuit. It worked fine in my previous location.
> Everything plugs into it, so I am not creating loops by running gear
> from different outlets.
>
> I have tried star-grounding the power distribution unit - i.e.,
> running a wire from the chasis of the unit to the building's ground
> wires. No change.
>
> Any suggestions for cleaning up the AC? Is my only option a
> regenerator?
>
>
>
>
>
>
> On 21 Apr 2005 07:57:20 -0700, "Mark" <makolber@yahoo.com> wrote:
>
> >you hear the crackling and clicks even when there is no audio
playing
> >through the pre-amps?
> >that would not be non-linear distortion but ok...
> >
> >or do you hear clicks only at the loudest peaks of the audio? that
> >would not likley be a power line problem (unless your line voltage
was
> >very low but then you lights would be dim etc)
> >
> >
> >connect a line powered AM radio. If you hear the same crackles and
> >clicks you MAY have some line noise. But a good pre with correct
> >wiring should reject that stuff anyway. If everything has just
been
> >re-wired in the new studio, I would troubleshoot the wiring.
Connect a
> >mic directly to the pre and see what happens.
> >
> >Mark
> >
> >
> >
> >
> >Mark
Anonymous
April 21, 2005 4:41:22 PM

Archived from groups: rec.audio.pro (More info?)

Seems like you have ground loops and poor AC.

To view it spectrally, you need a 10:1 or 100:1 probe and connect to
any analyzer. Be careful if you are using a softanalyzer using a sound
card. You need to do extra things.

To attempt solving it, try putting a power isolation transformer
between your amp and your wall circuit. If you have biased microphones
in the setup too try isolating them too with a really good audio
transformer.

Ruchir Dave wrote:
> Harry Houdini wrote:
> > Mark,
> >
> > Thanks for your help.
> >
> > In answer to your questions:
> >
> > - the noise from the preamps only occurs during recording. If I
loop
> a
> > generator signal (sine, pink noise etc) through any premap and
watch
> > the results in a software-based analyzer, I see pronounced peaks at
> > 60Hz + related harmonics and there is a lot fluctuation at those
> > frequencies.
> >
> > - the noise coming from my speakers, an intermittant crackle + AC
> hum,
> > happens when no audio is going through them (preamp and amp are
just
> > on). When I do play audio, I hear a loud click/pop every once in a
> > while. This noise is definitely not in the source material being
> > played. It have unplugged all inputs to the preamp, leaving only
its
> > connection to the power amp, amp to speakers. The background hash
and
> > crackling is still there.
> >
> > Evidently I have a ground issue + extremely dirty AC, but I'm at
> wit's
> > end trying to get rid of it. I have a 20amp balanced power
> transformer
> > which is on its own circuit. It worked fine in my previous
location.
> > Everything plugs into it, so I am not creating loops by running
gear
> > from different outlets.
> >
> > I have tried star-grounding the power distribution unit - i.e.,
> > running a wire from the chasis of the unit to the building's ground
> > wires. No change.
> >
> > Any suggestions for cleaning up the AC? Is my only option a
> > regenerator?
> >
> >
> >
> >
> >
> >
> > On 21 Apr 2005 07:57:20 -0700, "Mark" <makolber@yahoo.com> wrote:
> >
> > >you hear the crackling and clicks even when there is no audio
> playing
> > >through the pre-amps?
> > >that would not be non-linear distortion but ok...
> > >
> > >or do you hear clicks only at the loudest peaks of the audio?
that
> > >would not likley be a power line problem (unless your line voltage
> was
> > >very low but then you lights would be dim etc)
> > >
> > >
> > >connect a line powered AM radio. If you hear the same crackles
and
> > >clicks you MAY have some line noise. But a good pre with correct
> > >wiring should reject that stuff anyway. If everything has just
> been
> > >re-wired in the new studio, I would troubleshoot the wiring.
> Connect a
> > >mic directly to the pre and see what happens.
> > >
> > >Mark
> > >
> > >
> > >
> > >
> > >Mark
Anonymous
April 21, 2005 5:02:04 PM

Archived from groups: rec.audio.pro (More info?)

So do you hear these same noises through headphones from the same
source? Try a different pre amp and/or power amp. Sounds like a
possible amp problem.
April 21, 2005 5:22:27 PM

Archived from groups: rec.audio.pro (More info?)

What kind og preamp is it?

I would not be so quick to blame the AC power. PA's desks work all the
time in close proximity to large lighting and air conditioning systems
without issue. Good audio equipment should be pretty immune to AC power
noise. An AM radio will give you a quick idea if you have AC noise
problems. If you don't hear LOTs of noise on an AM radio, its probably
OK.

If you've just re-wired your studio, there are lots of things that
could be wrong. My suggestion for troubleshooting is to simplify your
system as much as possible and see what happens.

Are you in an industrial area or an area with RF transmissions towers,
maybe a cell phone tower? Your symptoms could also be caused by RFI
from a TV station (59.94 Hz vertical sync buzz sounds almost the same
as 60 Hz ) and FM 2 way land mobile transmitters that key on and off
can cause clicks.

Mark
Anonymous
April 21, 2005 6:10:17 PM

Archived from groups: rec.audio.pro (More info?)

On Thu, 21 Apr 2005 08:21:47 -0400, Harry Houdini <harry@houdini.com>
wrote:

> Hi,
>
> I was wondering if anyone could tell me if it's possible to view a
> detailed waveform of the AC coming from my walls. I've seen pictures
> taken from oscilloscopes, so I think it's possbile. Does anyone know
> the procedure? Are there any other ways to perform this analysis
> without an oscilloscope?
>

If you know enough about electricity to be safe then you'll probably
already know of an easy way to do this. If you can't figure it out then
you probably wouldn't be able to safely make use of the answer.

Cheers.

James.
Anonymous
April 21, 2005 6:10:18 PM

Archived from groups: rec.audio.pro (More info?)

James,

Thank you for expressing concerns for my safety :)  You're right, I am
inexperienced at this. That being said, would you know of any good
reference materials I could get up-to-speed with?

On Thu, 21 Apr 2005 14:10:17 +0100, "James Perrett"
<James.Perrett@soc.soton.ac.uk> wrote:

>On Thu, 21 Apr 2005 08:21:47 -0400, Harry Houdini <harry@houdini.com>
>wrote:
>
>> Hi,
>>
>> I was wondering if anyone could tell me if it's possible to view a
>> detailed waveform of the AC coming from my walls. I've seen pictures
>> taken from oscilloscopes, so I think it's possbile. Does anyone know
>> the procedure? Are there any other ways to perform this analysis
>> without an oscilloscope?
>>
>
>If you know enough about electricity to be safe then you'll probably
>already know of an easy way to do this. If you can't figure it out then
>you probably wouldn't be able to safely make use of the answer.
>
>Cheers.
>
>James.
April 21, 2005 11:04:38 PM

Archived from groups: rec.audio.pro (More info?)

hmmm

well then I have no idea...

maybe you can record some of the noise and post it so we can hear it
and maybe someone can identify it.

Good luck, please let us all know what it was when you figure it out.

Mark
Anonymous
April 21, 2005 11:55:02 PM

Archived from groups: rec.audio.pro (More info?)

HH
If you say everything else is the same as was connected previously, I think
you should check out the integrity of the building's wiring, particularly
ensuring milliohms of ground /earth wiring (is it of the recommended
gauge?), especially if your gear is several floors away from the electricity
supply entry and re-distribution point.
If you are based in an industrial area,
when is the majority of clicks noticed? Day or night? Does it abate/reduce
on weekends/holidays?
Lift/elevator and industrial motors can cause huge spikes, also your
studio's single phase consumption may be way out of balance with the loads
on other phases nearby. But this would affect your mains voltage and you
would notice simultaneous fluctuations of lighting steadiness.

"Harry Houdini" <harry@houdini.com> wrote in message
news:klif611nn5ogm8t7e8bav0oddocs1hj5cs@4ax.com...
> Mark,
>
> Thanks for your help.
>
> In answer to your questions:
>
> - the noise from the preamps only occurs during recording. If I loop a
> generator signal (sine, pink noise etc) through any premap and watch
> the results in a software-based analyzer, I see pronounced peaks at
> 60Hz + related harmonics and there is a lot fluctuation at those
> frequencies.
>
> - the noise coming from my speakers, an intermittant crackle + AC hum,
> happens when no audio is going through them (preamp and amp are just
> on). When I do play audio, I hear a loud click/pop every once in a
> while. This noise is definitely not in the source material being
> played. It have unplugged all inputs to the preamp, leaving only its
> connection to the power amp, amp to speakers. The background hash and
> crackling is still there.
>
> Evidently I have a ground issue + extremely dirty AC, but I'm at wit's
> end trying to get rid of it. I have a 20amp balanced power transformer
> which is on its own circuit. It worked fine in my previous location.
> Everything plugs into it, so I am not creating loops by running gear
> from different outlets.
>
> I have tried star-grounding the power distribution unit - i.e.,
> running a wire from the chasis of the unit to the building's ground
> wires. No change.
>
> Any suggestions for cleaning up the AC? Is my only option a
> regenerator?
>
>
>
>
>
>
> On 21 Apr 2005 07:57:20 -0700, "Mark" <makolber@yahoo.com> wrote:
>
>>you hear the crackling and clicks even when there is no audio playing
>>through the pre-amps?
>>that would not be non-linear distortion but ok...
>>
>>or do you hear clicks only at the loudest peaks of the audio? that
>>would not likley be a power line problem (unless your line voltage was
>>very low but then you lights would be dim etc)
>>
>>
>>connect a line powered AM radio. If you hear the same crackles and
>>clicks you MAY have some line noise. But a good pre with correct
>>wiring should reject that stuff anyway. If everything has just been
>>re-wired in the new studio, I would troubleshoot the wiring. Connect a
>>mic directly to the pre and see what happens.
>>
>>Mark
>>
>>
>>
>>
>>Mark
>
Anonymous
April 22, 2005 12:13:12 AM

Archived from groups: rec.audio.pro (More info?)

On 21 Apr 2005 13:22:27 -0700, "Mark" <makolber@yahoo.com> wrote:

>What kind og preamp is it?

I have a Bryston Point 5B preamp and a 3B amp. Both are just back from
Bryston with a clean bill of health.

>I would not be so quick to blame the AC power. PA's desks work all the
>time in close proximity to large lighting and air conditioning systems
>without issue. Good audio equipment should be pretty immune to AC power
>noise. An AM radio will give you a quick idea if you have AC noise
>problems. If you don't hear LOTs of noise on an AM radio, its probably
>OK.

I tried your suggestion of the AM radio, but there was so much static
and hum that I couldn't tell if there were any of those
clicks/crackles.

I'm way out in the country, so that may explain poor AM reception. The
closest towers are 12 miles away. That, and I'm in a bit of a valley.

>If you've just re-wired your studio, there are lots of things that
>could be wrong. My suggestion for troubleshooting is to simplify your
>system as much as possible and see what happens.

Thanks for the suggestion. I tried that too. I started with only one
piece plugged in at a time. The sound was there no matter what.

>Are you in an industrial area or an area with RF transmissions towers,
>maybe a cell phone tower? Your symptoms could also be caused by RFI
>from a TV station (59.94 Hz vertical sync buzz sounds almost the same
>as 60 Hz ) and FM 2 way land mobile transmitters that key on and off
>can cause clicks.

see my comments above.

>Mark
Anonymous
April 22, 2005 12:15:07 AM

Archived from groups: rec.audio.pro (More info?)

Dave,

Thanks for your suggestion of trying audio transformers. As far as AC
is concerned, I have a balanced power transformer - Furman IT-1220.
This noise seems to make it by anyhow!


On 21 Apr 2005 12:41:22 -0700, "Ruchir Dave" <ruchir@gmail.com> wrote:

>Seems like you have ground loops and poor AC.
>
>To view it spectrally, you need a 10:1 or 100:1 probe and connect to
>any analyzer. Be careful if you are using a softanalyzer using a sound
>card. You need to do extra things.
>
>To attempt solving it, try putting a power isolation transformer
>between your amp and your wall circuit. If you have biased microphones
>in the setup too try isolating them too with a really good audio
>transformer.
>
>Ruchir Dave wrote:
>> Harry Houdini wrote:
>> > Mark,
>> >
>> > Thanks for your help.
>> >
>> > In answer to your questions:
>> >
>> > - the noise from the preamps only occurs during recording. If I
>loop
>> a
>> > generator signal (sine, pink noise etc) through any premap and
>watch
>> > the results in a software-based analyzer, I see pronounced peaks at
>> > 60Hz + related harmonics and there is a lot fluctuation at those
>> > frequencies.
>> >
>> > - the noise coming from my speakers, an intermittant crackle + AC
>> hum,
>> > happens when no audio is going through them (preamp and amp are
>just
>> > on). When I do play audio, I hear a loud click/pop every once in a
>> > while. This noise is definitely not in the source material being
>> > played. It have unplugged all inputs to the preamp, leaving only
>its
>> > connection to the power amp, amp to speakers. The background hash
>and
>> > crackling is still there.
>> >
>> > Evidently I have a ground issue + extremely dirty AC, but I'm at
>> wit's
>> > end trying to get rid of it. I have a 20amp balanced power
>> transformer
>> > which is on its own circuit. It worked fine in my previous
>location.
>> > Everything plugs into it, so I am not creating loops by running
>gear
>> > from different outlets.
>> >
>> > I have tried star-grounding the power distribution unit - i.e.,
>> > running a wire from the chasis of the unit to the building's ground
>> > wires. No change.
>> >
>> > Any suggestions for cleaning up the AC? Is my only option a
>> > regenerator?
>> >
>> >
>> >
>> >
>> >
>> >
>> > On 21 Apr 2005 07:57:20 -0700, "Mark" <makolber@yahoo.com> wrote:
>> >
>> > >you hear the crackling and clicks even when there is no audio
>> playing
>> > >through the pre-amps?
>> > >that would not be non-linear distortion but ok...
>> > >
>> > >or do you hear clicks only at the loudest peaks of the audio?
>that
>> > >would not likley be a power line problem (unless your line voltage
>> was
>> > >very low but then you lights would be dim etc)
>> > >
>> > >
>> > >connect a line powered AM radio. If you hear the same crackles
>and
>> > >clicks you MAY have some line noise. But a good pre with correct
>> > >wiring should reject that stuff anyway. If everything has just
>> been
>> > >re-wired in the new studio, I would troubleshoot the wiring.
>> Connect a
>> > >mic directly to the pre and see what happens.
>> > >
>> > >Mark
>> > >
>> > >
>> > >
>> > >
>> > >Mark
Anonymous
April 22, 2005 12:19:17 AM

Archived from groups: rec.audio.pro (More info?)

Jim,

Thanks for your input!

In answer to your comments/questions:

- Is there any way I can check the resistance of the ground myself?
How would I do that? (I have a digital multimeter kicking around
somewhere...)

- I am based in the country - no industry around for at least 12
miles.

- Noises are not related to the time of day.

- Lights are steady, but the alarms in other UPS units go off in the
morning. I do not use these particular units for audio.


On Thu, 21 Apr 2005 19:55:02 GMT, "Jim Gregory"
<jim.greg@ntlworld.com> wrote:

>HH
>If you say everything else is the same as was connected previously, I think
>you should check out the integrity of the building's wiring, particularly
>ensuring milliohms of ground /earth wiring (is it of the recommended
>gauge?), especially if your gear is several floors away from the electricity
>supply entry and re-distribution point.
>If you are based in an industrial area,
>when is the majority of clicks noticed? Day or night? Does it abate/reduce
>on weekends/holidays?
>Lift/elevator and industrial motors can cause huge spikes, also your
>studio's single phase consumption may be way out of balance with the loads
>on other phases nearby. But this would affect your mains voltage and you
>would notice simultaneous fluctuations of lighting steadiness.
>
>"Harry Houdini" <harry@houdini.com> wrote in message
>news:klif611nn5ogm8t7e8bav0oddocs1hj5cs@4ax.com...
>> Mark,
>>
>> Thanks for your help.
>>
>> In answer to your questions:
>>
>> - the noise from the preamps only occurs during recording. If I loop a
>> generator signal (sine, pink noise etc) through any premap and watch
>> the results in a software-based analyzer, I see pronounced peaks at
>> 60Hz + related harmonics and there is a lot fluctuation at those
>> frequencies.
>>
>> - the noise coming from my speakers, an intermittant crackle + AC hum,
>> happens when no audio is going through them (preamp and amp are just
>> on). When I do play audio, I hear a loud click/pop every once in a
>> while. This noise is definitely not in the source material being
>> played. It have unplugged all inputs to the preamp, leaving only its
>> connection to the power amp, amp to speakers. The background hash and
>> crackling is still there.
>>
>> Evidently I have a ground issue + extremely dirty AC, but I'm at wit's
>> end trying to get rid of it. I have a 20amp balanced power transformer
>> which is on its own circuit. It worked fine in my previous location.
>> Everything plugs into it, so I am not creating loops by running gear
>> from different outlets.
>>
>> I have tried star-grounding the power distribution unit - i.e.,
>> running a wire from the chasis of the unit to the building's ground
>> wires. No change.
>>
>> Any suggestions for cleaning up the AC? Is my only option a
>> regenerator?
>>
>>
>>
>>
>>
>>
>> On 21 Apr 2005 07:57:20 -0700, "Mark" <makolber@yahoo.com> wrote:
>>
>>>you hear the crackling and clicks even when there is no audio playing
>>>through the pre-amps?
>>>that would not be non-linear distortion but ok...
>>>
>>>or do you hear clicks only at the loudest peaks of the audio? that
>>>would not likley be a power line problem (unless your line voltage was
>>>very low but then you lights would be dim etc)
>>>
>>>
>>>connect a line powered AM radio. If you hear the same crackles and
>>>clicks you MAY have some line noise. But a good pre with correct
>>>wiring should reject that stuff anyway. If everything has just been
>>>re-wired in the new studio, I would troubleshoot the wiring. Connect a
>>>mic directly to the pre and see what happens.
>>>
>>>Mark
>>>
>>>
>>>
>>>
>>>Mark
>>
>
Anonymous
April 22, 2005 12:20:53 AM

Archived from groups: rec.audio.pro (More info?)

Tymish,

These noises still occur in headphones, plugged directly in my DAC.
Unfortunately, I have only one preamp and power amp.

On 21 Apr 2005 13:02:04 -0700, tymish@hotmail.com wrote:

>So do you hear these same noises through headphones from the same
>source? Try a different pre amp and/or power amp. Sounds like a
>possible amp problem.
Anonymous
April 22, 2005 12:28:35 AM

Archived from groups: rec.audio.pro (More info?)

>So have you looked for groound loops?

I always thought ground loops occurred when a signal has the option of
several grounds. Trying my gear one piece at a time in my Furman IT
1220, with nothing else connected to the unit, I still hear the noises
and hum.

The unit itself does not hum, so I can rule out mechanical noise, no?

>Running gear from different outlets does not create loops, it just makes
>existing loops bigger. A proper ground scheme prevents that from ever
>being a problem.

Would you be able to direct to more info/specs on a "proper ground
scheme"?

>>I have tried star-grounding the power distribution unit - i.e.,
>>running a wire from the chasis of the unit to the building's ground
>>wires. No change.
>
>Ground loops are caused by TOO MANY ground paths. Adding more makes
>the problem worse.



>>Any suggestions for cleaning up the AC? Is my only option a
>>regenerator?
>
>What is a regenerator? Do you mean an M-G set?

see

http://www.audiophileaps.com/
http://www.psaudio.com/products/p1000.asp
http://www.exactpower.com


>--scott
Anonymous
April 22, 2005 1:16:19 AM

Archived from groups: rec.audio.pro (More info?)

"Harry Houdini" <harry@houdini.com> wrote in message
news:7sgg6198vacq274667bfg6gmvjfn19nvkf@4ax.com...
>
>
>>So have you looked for groound loops?
>
> I always thought ground loops occurred when a signal has the option of
> several grounds. Trying my gear one piece at a time in my Furman IT
> 1220, with nothing else connected to the unit, I still hear the noises
> and hum.
>
> The unit itself does not hum, so I can rule out mechanical noise, no?
>
>>Running gear from different outlets does not create loops, it just makes
>>existing loops bigger. A proper ground scheme prevents that from ever
>>being a problem.
>
> Would you be able to direct to more info/specs on a "proper ground
> scheme"?
>
>>>I have tried star-grounding the power distribution unit - i.e.,
>>>running a wire from the chasis of the unit to the building's ground
>>>wires. No change.
>>
>>Ground loops are caused by TOO MANY ground paths. Adding more makes
>>the problem worse.
>
>
>
>>>Any suggestions for cleaning up the AC? Is my only option a
>>>regenerator?
>>
>>What is a regenerator? Do you mean an M-G set?
>
> see
>
> http://www.audiophileaps.com/
> http://www.psaudio.com/products/p1000.asp
> http://www.exactpower.com
>
>
>>--scott

What happens if you take said gear over to another "studio" (e.g. friend's
house, work) and plug it in? Do you still get the same noise? If not, then
I'd say it's time to either buy a decent power conditioner or hire an
electrician (or both?).

Craig
Anonymous
April 22, 2005 1:34:31 AM

Archived from groups: rec.audio.pro (More info?)

Harry Houdini <harry@houdini.com> wrote:
>
>Thanks for your suggestion of trying audio transformers. As far as AC
>is concerned, I have a balanced power transformer - Furman IT-1220.
>This noise seems to make it by anyhow!

That's a sign that it probably doesn't have anything to do with the power
line.

Audio transformers allow you to break grounds. You need a consistent
grounding scheme before you even think about anything else, because
without it you can't even try to diagnose other problems.
--scott


--
"C'est un Nagra. C'est suisse, et tres, tres precis."
Anonymous
April 22, 2005 8:26:34 AM

Archived from groups: rec.audio.pro (More info?)

Harry Houdini wrote:

> >So have you looked for groound loops?
>
> I always thought ground loops occurred when a signal has the option of
> several grounds. Trying my gear one piece at a time in my Furman IT
> 1220, with nothing else connected to the unit, I still hear the noises
> and hum.
>
> The unit itself does not hum, so I can rule out mechanical noise, no?
>
> >Running gear from different outlets does not create loops, it just makes
> >existing loops bigger. A proper ground scheme prevents that from ever
> >being a problem.
>
> Would you be able to direct to more info/specs on a "proper ground
> scheme"?
>
> >>I have tried star-grounding the power distribution unit - i.e.,
> >>running a wire from the chasis of the unit to the building's ground
> >>wires. No change.
> >
> >Ground loops are caused by TOO MANY ground paths. Adding more makes
> >the problem worse.
>
> >>Any suggestions for cleaning up the AC? Is my only option a
> >>regenerator?
> >
> >What is a regenerator? Do you mean an M-G set?
>
> see
>
> http://www.audiophileaps.com/
> http://www.psaudio.com/products/p1000.asp
> http://www.exactpower.com
>
> >--scott

Ahh... An always on UPS without the battery, in a snake oil bath.
If your problem is that you have a lot of RFI/EMI coming up your
power line, this may help.
You said you setup in a new location. New side of the room,
different room, different building, different town, etc.? This new
location was last checked by a competent, locally licensed
electrician when?
Back to basics. Do the plugs have two or three pins? Is the
ground pin actually connected to the building electrical ground?
Buy one of those little three bulb outlet testers and check the
plugs for the right bulbs lighting up. Wiggle the thing while
checking it. Buy a long, heavy gauge extension cord. Plug
it in at the plug next to your building power panel and try
running your setup from that. Try it at other outlets around
the area.
Hire a locally licensed electrician to fix any wiring faults
you have found. While he is there, get an estimate for
installing a brand new set of isolated ground outlets for
your recording studio.

--Dale
Anonymous
April 22, 2005 8:32:02 AM

Archived from groups: rec.audio.pro (More info?)

Harry Houdini wrote:

> Jim,
>
> Thanks for your input!
>
> In answer to your comments/questions:
>
> - Is there any way I can check the resistance of the ground myself?
> How would I do that? (I have a digital multimeter kicking around
> somewhere...)
>
> - I am based in the country - no industry around for at least 12
> miles.
>
> - Noises are not related to the time of day.
>
> - Lights are steady, but the alarms in other UPS units go off in the
> morning. I do not use these particular units for audio.

UPS alarms going off regularly is a sign of bad power stuff. The
powerline analyzer will help you track that down and get on your
power provider to fix problems that they may be responsible for.
going every morning at about the same time is probably some
large piece of electric equipment starting up each morning.

--Dale
April 22, 2005 3:27:37 PM

Archived from groups: rec.audio.pro (More info?)

can you post an MP3 recording of the noise that is haunting you?

Mark
April 22, 2005 6:02:17 PM

Archived from groups: rec.audio.pro (More info?)

can someone help Harry with this

I know you can't post an MP3 directly to the group but there is another
way to do it.

Mark
Anonymous
April 22, 2005 7:01:03 PM

Archived from groups: rec.audio.pro (More info?)

On Thu, 21 Apr 2005 10:41:05 -0400, Harry Houdini <harry@houdini.com>
wrote:

> James,
>
> Thank you for expressing concerns for my safety :)  You're right, I am
> inexperienced at this. That being said, would you know of any good
> reference materials I could get up-to-speed with?
>

Probably a good basic electrical engineering text book that covers
transformers - I'm not sure what the current recommended books are.

Cheers.

James.
Anonymous
April 22, 2005 8:31:02 PM

Archived from groups: rec.audio.pro (More info?)

HH
I ask if you're in a ranch/cottage/bungalow with overhead delivery poles?
You can rent a special meter to measure electrical wiring loss from entry
point. Ah! Is there a separate safety earth/ground wire busbar on your
premises or is it merely obtained via the bonding of steel-conduit
infrastructure, which can break down or could be botched/vandalised?
Is there an ground/earth rod (not for a lightning conductor) in the soil
outside? If so, wet it!!!

Why do these alarms go off in mornings? Back-EMF or brief collapse somewhere
on your feeder is causing a spike or fast drop-out to influence them.
If you can't measure the integrity of your ground path, then buy an
anti-surge spike remover/cleaner to preceed your equipment. These will clamp
any sudden AC voltage pulses to 15-20% above nominal. Yet the surge will
still be present, but attenuated.
****Are you sure someone isn't hacking into the power supply illegitimately
for a free ride?
Your poor AM reception (is that on distant or nearby stations or both?)
tells a lot. Is that receiver battery-operated or mains?
BTW, what are UPS units?? Don't know this abbreviation in UK!
With your nom de plume, you should be seen to be able to get out of any
imposed bother!
Jim

"Harry Houdini" <harry@houdini.com> wrote in message
news:4hgg61d8iprseun59kll2539fde1b3fcvn@4ax.com...
> Jim,
>
> Thanks for your input!
>
> In answer to your comments/questions:
>
> - Is there any way I can check the resistance of the ground myself?
> How would I do that? (I have a digital multimeter kicking around
> somewhere...)
>
> - I am based in the country - no industry around for at least 12
> miles.
>
> - Noises are not related to the time of day.
>
> - Lights are steady, but the alarms in other UPS units go off in the
> morning. I do not use these particular units for audio.
>
>
> On Thu, 21 Apr 2005 19:55:02 GMT, "Jim Gregory"
> <jim.greg@ntlworld.com> wrote:
>
>>HH
>>If you say everything else is the same as was connected previously, I
>>think
>>you should check out the integrity of the building's wiring, particularly
>>ensuring milliohms of ground /earth wiring (is it of the recommended
>>gauge?), especially if your gear is several floors away from the
>>electricity
>>supply entry and re-distribution point.
>>If you are based in an industrial area,
>>when is the majority of clicks noticed? Day or night? Does it abate/reduce
>>on weekends/holidays?
>>Lift/elevator and industrial motors can cause huge spikes, also your
>>studio's single phase consumption may be way out of balance with the loads
>>on other phases nearby. But this would affect your mains voltage and you
>>would notice simultaneous fluctuations of lighting steadiness.
>>
>>"Harry Houdini" <harry@houdini.com> wrote in message
>>news:klif611nn5ogm8t7e8bav0oddocs1hj5cs@4ax.com...
>>> Mark,
>>>
>>> Thanks for your help.
>>>
>>> In answer to your questions:
>>>
>>> - the noise from the preamps only occurs during recording. If I loop a
>>> generator signal (sine, pink noise etc) through any premap and watch
>>> the results in a software-based analyzer, I see pronounced peaks at
>>> 60Hz + related harmonics and there is a lot fluctuation at those
>>> frequencies.
>>>
>>> - the noise coming from my speakers, an intermittant crackle + AC hum,
>>> happens when no audio is going through them (preamp and amp are just
>>> on). When I do play audio, I hear a loud click/pop every once in a
>>> while. This noise is definitely not in the source material being
>>> played. It have unplugged all inputs to the preamp, leaving only its
>>> connection to the power amp, amp to speakers. The background hash and
>>> crackling is still there.
>>>
>>> Evidently I have a ground issue + extremely dirty AC, but I'm at wit's
>>> end trying to get rid of it. I have a 20amp balanced power transformer
>>> which is on its own circuit. It worked fine in my previous location.
>>> Everything plugs into it, so I am not creating loops by running gear
>>> from different outlets.
>>>
>>> I have tried star-grounding the power distribution unit - i.e.,
>>> running a wire from the chasis of the unit to the building's ground
>>> wires. No change.
>>>
>>> Any suggestions for cleaning up the AC? Is my only option a
>>> regenerator?
>>>
>>>
>>>
>>>
>>>
>>>
>>> On 21 Apr 2005 07:57:20 -0700, "Mark" <makolber@yahoo.com> wrote:
>>>
>>>>you hear the crackling and clicks even when there is no audio playing
>>>>through the pre-amps?
>>>>that would not be non-linear distortion but ok...
>>>>
>>>>or do you hear clicks only at the loudest peaks of the audio? that
>>>>would not likley be a power line problem (unless your line voltage was
>>>>very low but then you lights would be dim etc)
>>>>
>>>>
>>>>connect a line powered AM radio. If you hear the same crackles and
>>>>clicks you MAY have some line noise. But a good pre with correct
>>>>wiring should reject that stuff anyway. If everything has just been
>>>>re-wired in the new studio, I would troubleshoot the wiring. Connect a
>>>>mic directly to the pre and see what happens.
>>>>
>>>>Mark
>>>>
>>>>
>>>>
>>>>
>>>>Mark
>>>
>>
>
Anonymous
April 22, 2005 8:31:03 PM

Archived from groups: rec.audio.pro (More info?)

Jim!

Ha-ha :)  Your last comment brought a smile to my face. Guess I'm not
living up to my name, then - because I'm sure in a pickle.

In answer to your questions/comments

- yes, there are overhead deilvery poles about 300 ft from the house.
- you wouldn't happen to know the name of this test meter?
- Yes, there is an earth rod, which connects to the main power box.
- I already have a furman IT-1220 (Balanced power isolation
transformer), which isn't helping matters.
- a UPS = uninterrupted power supply, a battery backup such as those
offered by APC. I don't use these for serious audio, just my computers
that handle email, etc.
- Can't be sure the power isn't being hacked
- The AM receiver was powered via mains

Appreciate your time and effort.

HH


On Fri, 22 Apr 2005 16:31:02 GMT, "Jim Gregory"
<jim.greg@ntlworld.com> wrote:

>HH
>I ask if you're in a ranch/cottage/bungalow with overhead delivery poles?
>You can rent a special meter to measure electrical wiring loss from entry
>point. Ah! Is there a separate safety earth/ground wire busbar on your
>premises or is it merely obtained via the bonding of steel-conduit
>infrastructure, which can break down or could be botched/vandalised?
>Is there an ground/earth rod (not for a lightning conductor) in the soil
>outside? If so, wet it!!!
>
>Why do these alarms go off in mornings? Back-EMF or brief collapse somewhere
>on your feeder is causing a spike or fast drop-out to influence them.
>If you can't measure the integrity of your ground path, then buy an
>anti-surge spike remover/cleaner to preceed your equipment. These will clamp
>any sudden AC voltage pulses to 15-20% above nominal. Yet the surge will
>still be present, but attenuated.
>****Are you sure someone isn't hacking into the power supply illegitimately
>for a free ride?
>Your poor AM reception (is that on distant or nearby stations or both?)
>tells a lot. Is that receiver battery-operated or mains?
>BTW, what are UPS units?? Don't know this abbreviation in UK!
>With your nom de plume, you should be seen to be able to get out of any
>imposed bother!
>Jim
>
>"Harry Houdini" <harry@houdini.com> wrote in message
>news:4hgg61d8iprseun59kll2539fde1b3fcvn@4ax.com...
>> Jim,
>>
>> Thanks for your input!
>>
>> In answer to your comments/questions:
>>
>> - Is there any way I can check the resistance of the ground myself?
>> How would I do that? (I have a digital multimeter kicking around
>> somewhere...)
>>
>> - I am based in the country - no industry around for at least 12
>> miles.
>>
>> - Noises are not related to the time of day.
>>
>> - Lights are steady, but the alarms in other UPS units go off in the
>> morning. I do not use these particular units for audio.
>>
>>
>> On Thu, 21 Apr 2005 19:55:02 GMT, "Jim Gregory"
>> <jim.greg@ntlworld.com> wrote:
>>
>>>HH
>>>If you say everything else is the same as was connected previously, I
>>>think
>>>you should check out the integrity of the building's wiring, particularly
>>>ensuring milliohms of ground /earth wiring (is it of the recommended
>>>gauge?), especially if your gear is several floors away from the
>>>electricity
>>>supply entry and re-distribution point.
>>>If you are based in an industrial area,
>>>when is the majority of clicks noticed? Day or night? Does it abate/reduce
>>>on weekends/holidays?
>>>Lift/elevator and industrial motors can cause huge spikes, also your
>>>studio's single phase consumption may be way out of balance with the loads
>>>on other phases nearby. But this would affect your mains voltage and you
>>>would notice simultaneous fluctuations of lighting steadiness.
>>>
>>>"Harry Houdini" <harry@houdini.com> wrote in message
>>>news:klif611nn5ogm8t7e8bav0oddocs1hj5cs@4ax.com...
>>>> Mark,
>>>>
>>>> Thanks for your help.
>>>>
>>>> In answer to your questions:
>>>>
>>>> - the noise from the preamps only occurs during recording. If I loop a
>>>> generator signal (sine, pink noise etc) through any premap and watch
>>>> the results in a software-based analyzer, I see pronounced peaks at
>>>> 60Hz + related harmonics and there is a lot fluctuation at those
>>>> frequencies.
>>>>
>>>> - the noise coming from my speakers, an intermittant crackle + AC hum,
>>>> happens when no audio is going through them (preamp and amp are just
>>>> on). When I do play audio, I hear a loud click/pop every once in a
>>>> while. This noise is definitely not in the source material being
>>>> played. It have unplugged all inputs to the preamp, leaving only its
>>>> connection to the power amp, amp to speakers. The background hash and
>>>> crackling is still there.
>>>>
>>>> Evidently I have a ground issue + extremely dirty AC, but I'm at wit's
>>>> end trying to get rid of it. I have a 20amp balanced power transformer
>>>> which is on its own circuit. It worked fine in my previous location.
>>>> Everything plugs into it, so I am not creating loops by running gear
>>>> from different outlets.
>>>>
>>>> I have tried star-grounding the power distribution unit - i.e.,
>>>> running a wire from the chasis of the unit to the building's ground
>>>> wires. No change.
>>>>
>>>> Any suggestions for cleaning up the AC? Is my only option a
>>>> regenerator?
>>>>
>>>>
>>>>
>>>>
>>>>
>>>>
>>>> On 21 Apr 2005 07:57:20 -0700, "Mark" <makolber@yahoo.com> wrote:
>>>>
>>>>>you hear the crackling and clicks even when there is no audio playing
>>>>>through the pre-amps?
>>>>>that would not be non-linear distortion but ok...
>>>>>
>>>>>or do you hear clicks only at the loudest peaks of the audio? that
>>>>>would not likley be a power line problem (unless your line voltage was
>>>>>very low but then you lights would be dim etc)
>>>>>
>>>>>
>>>>>connect a line powered AM radio. If you hear the same crackles and
>>>>>clicks you MAY have some line noise. But a good pre with correct
>>>>>wiring should reject that stuff anyway. If everything has just been
>>>>>re-wired in the new studio, I would troubleshoot the wiring. Connect a
>>>>>mic directly to the pre and see what happens.
>>>>>
>>>>>Mark
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>Mark
>>>>
>>>
>>
>
Anonymous
April 22, 2005 8:31:46 PM

Archived from groups: rec.audio.pro (More info?)

Hi Mark,

I once tried to send an attachment to this group, but it rejected it
saying binary posts weren't permitted.

For starters, here's a visual. The click is highlighted.



On 22 Apr 2005 11:27:37 -0700, "Mark" <makolber@yahoo.com> wrote:

>can you post an MP3 recording of the noise that is haunting you?
>
>Mark
Anonymous
April 23, 2005 1:15:56 AM

Archived from groups: rec.audio.pro (More info?)

On Fri, 22 Apr 2005 14:02:17 -0700, Mark wrote:

> can someone help Harry with this
>
> I know you can't post an MP3 directly to the group but there is another
> way to do it.
>
> Mark

Harry, I assume it's the same picture you emailed to me.

Here it is:
http://69.93.9.106/click/click_example.jpg
Anonymous
April 23, 2005 2:02:16 AM

Archived from groups: rec.audio.pro (More info?)

In article <k4gg61t9o9cb7gvduigoi5qbdbq31tit90@4ax.com> harry@houdini.com writes:

> >My suggestion for troubleshooting is to simplify your
> >system as much as possible and see what happens.
>
> Thanks for the suggestion. I tried that too. I started with only one
> piece plugged in at a time. The sound was there no matter what.

Presumably that "one piece" was the power amplifier (with the speakers
connected, of course). Make up a couple of shorting plugs for the
input connectors and see if the noise goes away with the inputs
shorted. If you can't get rid of the noise in the power amplifier,
then it's either defective (regardless of what Bryston says) or you
have noise coming in on the power line that isn't adequately filtered
by the amplifier's power supply.



--
I'm really Mike Rivers - (mrivers@d-and-d.com)
However, until the spam goes away or Hell freezes over,
lots of IP addresses are blocked from this system. If
you e-mail me and it bounces, use your secret decoder ring
and reach me here: double-m-eleven-double-zero at yahoo
Anonymous
April 23, 2005 3:53:08 AM

Archived from groups: rec.audio.pro (More info?)

You have a fridge running there? Motors cause noise, esp when
switching on/off.
Un plug anything non audio and try again.

Good luck!



On Thu, 21 Apr 2005 08:21:47 -0400, Harry Houdini <harry@houdini.com>
wrote:

>Hi,
>
>I was wondering if anyone could tell me if it's possible to view a
>detailed waveform of the AC coming from my walls. I've seen pictures
>taken from oscilloscopes, so I think it's possbile. Does anyone know
>the procedure? Are there any other ways to perform this analysis
>without an oscilloscope?
>
>Appreciate your input,
>
>Harry
>
Anonymous
April 23, 2005 2:13:45 PM

Archived from groups: rec.audio.pro (More info?)

HH

I do know about UPS back-up supplies. I thought it was a term for a housing
unit!
Your mains-powered AM radio is picking up an abnormal amount of
interference, you say.
You are in a pickle!!

This is a typical (expensive) test meter for testing wiring integrity and
checking
low loop resistance
http://www.tlc-direct.co.uk/Main_Index/Test_Meters_Inde...

There will be several others but don't buy one - rent it!

Why, I ask myself, are you using a *balanced* power isolation xformer? What
VA
rating is a Furman IT-1220?
These need a balanced load (ie, centre-tapped mains input to match format of
power xformer's secondary), I imagine. Which means in your case: if you use
that device, disconnect the secondary centre-tap from ground. It may have
been done internally!
Read on....
If you must include one, just use a, say,1000VA isolation 1:1 transformer,
and bond one leg of its secondary to ground to simulate your supply neutral,
assuming you use 3 poles: Line and Neutral and safety earth/ground there!!
You *must* do this because distribution and appliance fuses are only ever
inserted on Line side.[A blown fuse in what is a pseudo-neutral would make
the rest of its load live and therefore unsafe.]

"Harry Houdini" <harry@houdini.com> wrote in message
news:mmei61lejh0rpksqvhulmeqscd93rmecas@4ax.com...
> Jim!
>
> Ha-ha :)  Your last comment brought a smile to my face. Guess I'm not
> living up to my name, then - because I'm sure in a pickle.
>
> In answer to your questions/comments
>
> - yes, there are overhead deilvery poles about 300 ft from the house.
> - you wouldn't happen to know the name of this test meter?
> - Yes, there is an earth rod, which connects to the main power box.
> - I already have a furman IT-1220 (Balanced power isolation
> transformer), which isn't helping matters.
> - a UPS = uninterrupted power supply, a battery backup such as those
> offered by APC. I don't use these for serious audio, just my computers
> that handle email, etc.
> - Can't be sure the power isn't being hacked
> - The AM receiver was powered via mains
>
> Appreciate your time and effort.
>
> HH
>
>
> On Fri, 22 Apr 2005 16:31:02 GMT, "Jim Gregory"
> <jim.greg@ntlworld.com> wrote:
>
>>HH
>>I ask if you're in a ranch/cottage/bungalow with overhead delivery poles?
>>You can rent a special meter to measure electrical wiring loss from entry
>>point. Ah! Is there a separate safety earth/ground wire busbar on your
>>premises or is it merely obtained via the bonding of steel-conduit
>>infrastructure, which can break down or could be botched/vandalised?
>>Is there an ground/earth rod (not for a lightning conductor) in the soil
>>outside? If so, wet it!!!
>>
>>Why do these alarms go off in mornings? Back-EMF or brief collapse
>>somewhere
>>on your feeder is causing a spike or fast drop-out to influence them.
>>If you can't measure the integrity of your ground path, then buy an
>>anti-surge spike remover/cleaner to preceed your equipment. These will
>>clamp
>>any sudden AC voltage pulses to 15-20% above nominal. Yet the surge will
>>still be present, but attenuated.
>>****Are you sure someone isn't hacking into the power supply
>>illegitimately
>>for a free ride?
>>Your poor AM reception (is that on distant or nearby stations or both?)
>>tells a lot. Is that receiver battery-operated or mains?
>>BTW, what are UPS units?? Don't know this abbreviation in UK!
>>With your nom de plume, you should be seen to be able to get out of any
>>imposed bother!
>>Jim
>>
>>"Harry Houdini" <harry@houdini.com> wrote in message
>>news:4hgg61d8iprseun59kll2539fde1b3fcvn@4ax.com...
>>> Jim,
>>>
>>> Thanks for your input!
>>>
>>> In answer to your comments/questions:
>>>
>>> - Is there any way I can check the resistance of the ground myself?
>>> How would I do that? (I have a digital multimeter kicking around
>>> somewhere...)
>>>
>>> - I am based in the country - no industry around for at least 12
>>> miles.
>>>
>>> - Noises are not related to the time of day.
>>>
>>> - Lights are steady, but the alarms in other UPS units go off in the
>>> morning. I do not use these particular units for audio.
>>>
>>>
>>> On Thu, 21 Apr 2005 19:55:02 GMT, "Jim Gregory"
>>> <jim.greg@ntlworld.com> wrote:
>>>
>>>>HH
>>>>If you say everything else is the same as was connected previously, I
>>>>think
>>>>you should check out the integrity of the building's wiring,
>>>>particularly
>>>>ensuring milliohms of ground /earth wiring (is it of the recommended
>>>>gauge?), especially if your gear is several floors away from the
>>>>electricity
>>>>supply entry and re-distribution point.
>>>>If you are based in an industrial area,
>>>>when is the majority of clicks noticed? Day or night? Does it
>>>>abate/reduce
>>>>on weekends/holidays?
>>>>Lift/elevator and industrial motors can cause huge spikes, also your
>>>>studio's single phase consumption may be way out of balance with the
>>>>loads
>>>>on other phases nearby. But this would affect your mains voltage and you
>>>>would notice simultaneous fluctuations of lighting steadiness.
>>>>
>>>>"Harry Houdini" <harry@houdini.com> wrote in message
>>>>news:klif611nn5ogm8t7e8bav0oddocs1hj5cs@4ax.com...
>>>>> Mark,
>>>>>
>>>>> Thanks for your help.
>>>>>
>>>>> In answer to your questions:
>>>>>
>>>>> - the noise from the preamps only occurs during recording. If I loop a
>>>>> generator signal (sine, pink noise etc) through any premap and watch
>>>>> the results in a software-based analyzer, I see pronounced peaks at
>>>>> 60Hz + related harmonics and there is a lot fluctuation at those
>>>>> frequencies.
>>>>>
>>>>> - the noise coming from my speakers, an intermittant crackle + AC hum,
>>>>> happens when no audio is going through them (preamp and amp are just
>>>>> on). When I do play audio, I hear a loud click/pop every once in a
>>>>> while. This noise is definitely not in the source material being
>>>>> played. It have unplugged all inputs to the preamp, leaving only its
>>>>> connection to the power amp, amp to speakers. The background hash and
>>>>> crackling is still there.
>>>>>
>>>>> Evidently I have a ground issue + extremely dirty AC, but I'm at wit's
>>>>> end trying to get rid of it. I have a 20amp balanced power transformer
>>>>> which is on its own circuit. It worked fine in my previous location.
>>>>> Everything plugs into it, so I am not creating loops by running gear
>>>>> from different outlets.
>>>>>
>>>>> I have tried star-grounding the power distribution unit - i.e.,
>>>>> running a wire from the chasis of the unit to the building's ground
>>>>> wires. No change.
>>>>>
>>>>> Any suggestions for cleaning up the AC? Is my only option a
>>>>> regenerator?
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>>
>>>>> On 21 Apr 2005 07:57:20 -0700, "Mark" <makolber@yahoo.com> wrote:
>>>>>
>>>>>>you hear the crackling and clicks even when there is no audio playing
>>>>>>through the pre-amps?
>>>>>>that would not be non-linear distortion but ok...
>>>>>>
>>>>>>or do you hear clicks only at the loudest peaks of the audio? that
>>>>>>would not likley be a power line problem (unless your line voltage was
>>>>>>very low but then you lights would be dim etc)
>>>>>>
>>>>>>
>>>>>>connect a line powered AM radio. If you hear the same crackles and
>>>>>>clicks you MAY have some line noise. But a good pre with correct
>>>>>>wiring should reject that stuff anyway. If everything has just been
>>>>>>re-wired in the new studio, I would troubleshoot the wiring. Connect
>>>>>>a
>>>>>>mic directly to the pre and see what happens.
>>>>>>
>>>>>>Mark
>>>>>>
>>>>>>
>>>>>>
>>>>>>
>>>>>>Mark
>>>>>
>>>>
>>>
>>
>
Anonymous
April 24, 2005 12:15:10 AM

Archived from groups: rec.audio.pro (More info?)

HH
A small thought!
If your premises are powered by 115VAC (nominal)....
You can make an approx 40dB resistive L pad (1/100) to view /analyse
wideband /watchdog at 1.15V rms.
Use 1 x 470k series + 1 x 5k1 shunt (2% metal oxide).
This eliminates any HP filtering introduced by step-down transformers on
load.
Insulate its input wiring well.

"Dale Farmer" <dale@cybercom.net> wrote in message
news:42687EAA.DA2893D2@cybercom.net...
>
>
> Harry Houdini wrote:
>
>> Jim,
>>
>> Thanks for your input!
>>
>> In answer to your comments/questions:
>>
>> - Is there any way I can check the resistance of the ground myself?
>> How would I do that? (I have a digital multimeter kicking around
>> somewhere...)
>>
>> - I am based in the country - no industry around for at least 12
>> miles.
>>
>> - Noises are not related to the time of day.
>>
>> - Lights are steady, but the alarms in other UPS units go off in the
>> morning. I do not use these particular units for audio.
>
> UPS alarms going off regularly is a sign of bad power stuff. The
> powerline analyzer will help you track that down and get on your
> power provider to fix problems that they may be responsible for.
> going every morning at about the same time is probably some
> large piece of electric equipment starting up each morning.
>
> --Dale
>
>
!