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Mark
 
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Default Power Switch "pop" noise ... help please?

Hello Everyone!

Recently, I fitted my preamp between my player and amp. When I turn it off,
I can hear a lound "crack" or "pop" noise coming from my speakers. Currently
my preamo is fitted with a push-on push -off power switch which turns on a
darlington pair which in turn switches on the relay for the mains. When
switched off, the relay will cut off AC while another pole will link B+ to
ground via a 4.7 10W resistor to discharge all the caps. I've heard that you
can actually fit a small AC cap between the relay teerminals like 0.1uf to
solve the problem but Ive not tried it yet. Could anyone recommend me the
correct action?

Thanks in advance!

Warm Regards,
Mark


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Bob
 
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On Fri, 23 Sep 2005 00:58:12 +0800, "Mark" wrote:

Hello Everyone!

Recently, I fitted my preamp between my player and amp. When I turn it off,
I can hear a lound "crack" or "pop" noise coming from my speakers. Currently
my preamo is fitted with a push-on push -off power switch which turns on a
darlington pair which in turn switches on the relay for the mains. When
switched off, the relay will cut off AC while another pole will link B+ to
ground via a 4.7 10W resistor to discharge all the caps. I've heard that you
can actually fit a small AC cap between the relay teerminals like 0.1uf to
solve the problem but Ive not tried it yet. Could anyone recommend me the
correct action?

Thanks in advance!

Warm Regards,
Mark


Did you say 4.7 OHMS??!!

Are ya daft, laddie?

Try 100k, 1/2 watt...

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Mark
 
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Ooops, I mean 4.7K Ohms. Sorry ....

"Bob" wrote in message
...
On Fri, 23 Sep 2005 00:58:12 +0800, "Mark" wrote:

Hello Everyone!

Recently, I fitted my preamp between my player and amp. When I turn it
off,
I can hear a lound "crack" or "pop" noise coming from my speakers.
Currently
my preamo is fitted with a push-on push -off power switch which turns on a
darlington pair which in turn switches on the relay for the mains. When
switched off, the relay will cut off AC while another pole will link B+ to
ground via a 4.7 10W resistor to discharge all the caps. I've heard that
you
can actually fit a small AC cap between the relay teerminals like 0.1uf to
solve the problem but Ive not tried it yet. Could anyone recommend me the
correct action?

Thanks in advance!

Warm Regards,
Mark


Did you say 4.7 OHMS??!!

Are ya daft, laddie?

Try 100k, 1/2 watt...



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Phil Allison
 
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"Mark"

Recently, I fitted my preamp between my player and amp. When I turn it
off, I can hear a lound "crack" or "pop" noise coming from my speakers.
Currently my preamo is fitted with a push-on push -off power switch which
turns on a darlington pair which in turn switches on the relay for the
mains. When switched off, the relay will cut off AC while another pole
will link B+ to ground via a 4.7 10W resistor to discharge all the caps.
I've heard that you can actually fit a small AC cap between the relay
teerminals like 0.1uf to solve the problem but Ive not tried it yet. Could
anyone recommend me the correct action?



** A cap across the contacts will suppress arcing and likely fix the noise
you hear.

You need a 0.047uF cap rated for AC supply use, these are known as "class
X" capacitors.

If none is available, then use two 0.1 uF, 400 volt film caps wired in
series instead.



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







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