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bt
 
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Default HELP! Weird cycling bursts of hiss

I have a four-year-old NAD reciever connected to some very old BIC
Venturi speakers. I haven't used it much recently, and when playing the
radio today, I noticed short bursts of hiss (something close to white
noise) interrupting the program ever so often--at least once per minute.
I chalked this up to reception problems, but it turns out the same
problem is present when playing cd's.

Any suggestions about possible causes of/remedies for this obnoxious
problem? Other than this, there is no indication that any of the
equipment is failing.

For what its worth, there is a history of strange electricity-related
failures (power supplies suddenly going out, outlets failing, light
bulbs burning out prematurely) here in my 1920s-era apartment.

Your help will be much appreciated.
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Barry Mann
 
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In bt-9F66AE.16595526112004@localhost, on 11/27/04
at 12:59 AM, bt said:

I have a four-year-old NAD reciever connected to some very old BIC
Venturi speakers. I haven't used it much recently, and when playing
the radio today, I noticed short bursts of hiss (something close to
white noise) interrupting the program ever so often--at least once
per minute. I chalked this up to reception problems, but it turns
out the same problem is present when playing cd's.


Any suggestions about possible causes of/remedies for this obnoxious
problem? Other than this, there is no indication that any of the
equipment is failing.


For what its worth, there is a history of strange electricity-related
failures (power supplies suddenly going out, outlets failing, light
bulbs burning out prematurely) here in my 1920s-era apartment.


Your help will be much appreciated.


Tune an AM portable radio to the quietest spot you can find at the high
end of the AM band. If the bursts of noise in your stereo correlate
with noise on the AM band, you probably have a power or appliance
problem. If this is true, move the radio to a new location and continue
to monitor. As you move closer to the problem, the noise bursts will
become louder on the radio. Hopefully, you can locate the source.

Check the audio system for physical problems by smacking it with an
open hand. If the system is healthy, you should be able to strike the
unit quite hard with no audible response. (by "hard" I mean, use enough
force that your hand may be uncomfortable, but don't bend any parts of
the cabinet, break the knobs, or display.)

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bt
 
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Thanks for the advice. I may have solved the problem--at least it has
played for a few minutes without trouble--by unplugging everything
(including a non-functional tv that was still plugged in to the same
power strip), cleaning the dusty power strip, replugging things (minus
the TV), turning the power strip off and then back on. Just for
curiosity's sake, I plugged the TV back in to see if I could clearly
identify it as the source of the problem, but it didn't cause any
immediate change. So I have tentatively remidied the symptom, but I
don't know what the problem was, except that i seems to have been
electrical. I tried your am radio test--no problem there--and the
intermittant bursts of hiss occured even when there was no source (e.g.,
when the amp was set to "cd" and the cd player was powered off.
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Barry Mann
 
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In bt-78338A.14272427112004@localhost, on 11/27/04
at 10:27 PM, bt said:

Thanks for the advice. I may have solved the problem--at least it has
played for a few minutes without trouble--by unplugging everything
(including a non-functional tv that was still plugged in to the same
power strip), cleaning the dusty power strip, replugging things (minus
the TV), turning the power strip off and then back on. Just for
curiosity's sake, I plugged the TV back in to see if I could clearly
identify it as the source of the problem, but it didn't cause any
immediate change. So I have tentatively remidied the symptom, but I
don't know what the problem was, except that i seems to have been
electrical. I tried your am radio test--no problem there--and the
intermittant bursts of hiss occured even when there was no source
(e.g., when the amp was set to "cd" and the cd player was powered
off.


Your problem could be associated with the power strip. There could be a
bad connection inside the power strip. (some of them are very poorly
made) Or, there could have been a bad connection to one of the devices
plugged into the strip.

If the problem returns, try to find out if the noise follows the volume
control.

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wordgame:123(abc):14 9 20 5 2 9 18 4 at 22 15 9 3 5 14 5 20 dot 3 15
13 (Barry Mann)
[sorry about the puzzle, spammers are ruining my mailbox]
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Barry Mann
 
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In bt-DF205F.07201428112004@localhost, on 11/28/04
at 03:20 PM, bt said:

In article ,
(Barry Mann) wrote:


If the problem returns, try to find out if the noise follows the volume
control.


If you mean could I adjust the volume of the noise bursts via the
volume control, yes I could. I also noticed that the noise bursts
were less loud when switched to "phono" as opposed to "cd" or the
tuner.


You can think of your system as being composed of three sections:
Source (which could be the internal tuner or an external device),
control (selector, tone, volume), and power amplifier. The Volume
control is usually between the control and amplifier sections.
(sometimes, usually in lower quality units, the tone controls are
between the Volume control and the amplifier) Since your noise volume
can be adjusted with the Volume control, the noise is probably not
associated with the power amplifier.

All seems fine now, but I am curious to understand what
happend--thanks again for your reply.


In any problem of this sort one must have a noise source and a
susceptible piece of equipment. Eliminating the noise, preventing the
noise from reaching the sensitive spot inside a unit, or improving the
unit to reduce its sensitivity, will help. At some point, if the noise
is intense enough, all equipment will respond. That's why military
grade equipment is so expensive. It is very robust, cheap, low class
consumer gear is not. (I'm not trying to cast your NAD in a bad light
-- it is not cheap, but it is also not military grade.)

Probably, your situation was power line related (the strip). A bad
connection can create an intense noise source that is close to your
equipment. A similarly intense noise generated in your neighbor's home
may not have caused any trouble for you.

Things can be very strange. I can recall a situation where a German
language shortwave broadcast leaked into a stereo receiver operating in
the northeast US. The shortwave reception was not associated with the
stereo's tuner. Since there was an amateur radio operator across the
street, I assumed there was an odd interaction between his equipment
and my customer's stereo receiver. I modified the receiver to reduce
it's sensitivity to the shortwave energy and solved the problem. Months
later I encountered the same situation (same model of receiver) in an
area about 20 miles from the first. Evidently, that model of receiver
had an extraordinary sensitivity to a particular shortwave frequency.

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spam:

wordgame:123(abc):14 9 20 5 2 9 18 4 at 22 15 9 3 5 14 5 20 dot 3 15
13 (Barry Mann)
[sorry about the puzzle, spammers are ruining my mailbox]
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bt
 
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Thanks once more.

As I said in my first post, I've experienced symptoms in my current
apartment that seem related to unreliable electricity, including a
couple of well-functioning appliances (that TV I mentioned is one) that
suddenly turned up "dead" (it seems the power supply failed while the
unit was turned off but plugged in).

Is there anything I can do (probably at the level of the power strip) to
minimize the effects of what seems to be an unstable electrical system?
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Barry Mann
 
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In bt-766B95.10245828112004@localhost, on 11/28/04
at 06:24 PM, bt said:

Thanks once more.


As I said in my first post, I've experienced symptoms in my current
apartment that seem related to unreliable electricity, including a
couple of well-functioning appliances (that TV I mentioned is one)
that suddenly turned up "dead" (it seems the power supply failed
while the unit was turned off but plugged in).


Is there anything I can do (probably at the level of the power strip)
to minimize the effects of what seems to be an unstable electrical
system?


Start using a "Power Conditioner" on everything. Simple surge
suppressors are not good enough for really bad situations.
Unfortunately, if the ground provided by the electrical system is poor,
none of the above will be really effective. Keep everything unplugged
unless you are using it.

Unstable electrical systems are fire hazards. Have regular fire drills,
make sure your life insurance is paid, and break the lease.

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wordgame:123(abc):14 9 20 5 2 9 18 4 at 22 15 9 3 5 14 5 20 dot 3 15
13 (Barry Mann)
[sorry about the puzzle, spammers are ruining my mailbox]
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