amplifier Popping

Fixed it, an output transistor had gone high gain.

Had a fault like this years ago, it was in Conn 651 theatre organ. The amp
had ASZ16'S and one of them had become faulty.
I remember repairing a Revox reel to reel, which would give a sound like a
thump when it was on, however, only now and
again, which made it hard to track down. Anyway we eventually found the
problem - a faulty ouput transistor.
Anyway that was then. These days I could hardly give a rats.

Hello Phil, did you drink that case of Diarrhoea I sent you? You did say
that your guests would drink anything - yuk!

Oh well back the Klystron Generator.

"Wayne Reid" <REMOVEgokangas@hotmail.com> wrote in message
news:MmWXb.1467$KS1.58475@nasal.pacific.net.au...
"mrocus" <silent@example.com> wrote in message
news:40277dd7$1@news.comindico.com.au...
Had a call from a friend in QLD, one of the amps in his studio setup
makes
a
popping sound when it is turned off.
He has 5 amplifiers same manufacturer, 4 are okay.

I have been out the repair business for a number of years, so I am abit
rusty these days. The grey hair and the grey matter don't help - G!

Any suggestions on a fix. or where to look

He has just sent me a circ diag, blimey these amps are old, they are in
an
electronic organ installation.

Unlike the other posters, I thought Phil's original comment was
reasonable.
But, I'll presume that the fault is not that the amp makes a popping sound
while it is powered off (as described) but rather, a pop or thump is heard
from the speaker at the time the power switch is turned off or shortly
afterwards.

Believe it or not, an ambiguous fault description is likely to generate a
lot of faulty diagnosis from an NG like this one.

Also, your own description of the diagnostics that you would have
performed
are a bit sus. When you ask people for help, don't make like you actually
know the answer or at least you could find it if only...

Take a look at http://www.diyaudio.com/forums/showthread/t-5678.html where
there is a reasonable description of two possible faults that could cause
the symptom you described. There is a description of one possible fix - if
the pop is the type of crackle caused by arcing within the mains switch.

If there is a short delay then a thump then you'll need to advise your
friend to either look in JAYCAR / DSE etc. for a speaker protector /
de-thump kit, or he'll need to get a tech to fix the actual fault -
presuming that the amp has not always made a thump (which could be a
design
flaw).

Isn't Usenet wonderful - WR
Click to expand...
 
You think that was ambiguous, people ring and email me and expect me to know
what they are talking about, "Is it a hum or a buzz" "What would cause
that?" How would I know when the caller lives hundreds of klms distant,
Pardon me I will look into Phil's crystal Ball. Nevertheless I don't mind
helping out and without ridiculing him. Phil are you listening?

Spent hours looking at organ keying circuitry, trying to discover why a
friend is having trouble with his Electronic theatre organ.
I tried to tell them that they couldn't hang midi off that particular model
without upsetting the voicing. The keying is part of the voicing! It took a
year for them trying to realise that what I said was true.

When a customer rings up and says that the coffee holder in her PC is
broken, what are you going to think - :)-)))??
Don't drink coffee?



"Wayne Reid" <REMOVEgokangas@hotmail.com> wrote in message
news:MmWXb.1467$KS1.58475@nasal.pacific.net.au...
"mrocus" <silent@example.com> wrote in message
news:40277dd7$1@news.comindico.com.au...
Had a call from a friend in QLD, one of the amps in his studio setup
makes
a
popping sound when it is turned off.
He has 5 amplifiers same manufacturer, 4 are okay.

I have been out the repair business for a number of years, so I am abit
rusty these days. The grey hair and the grey matter don't help - G!

Any suggestions on a fix. or where to look

He has just sent me a circ diag, blimey these amps are old, they are in
an
electronic organ installation.

Unlike the other posters, I thought Phil's original comment was
reasonable.
But, I'll presume that the fault is not that the amp makes a popping sound
while it is powered off (as described) but rather, a pop or thump is heard
from the speaker at the time the power switch is turned off or shortly
afterwards.

Believe it or not, an ambiguous fault description is likely to generate a
lot of faulty diagnosis from an NG like this one.

Also, your own description of the diagnostics that you would have
performed
are a bit sus. When you ask people for help, don't make like you actually
know the answer or at least you could find it if only...

Take a look at http://www.diyaudio.com/forums/showthread/t-5678.html where
there is a reasonable description of two possible faults that could cause
the symptom you described. There is a description of one possible fix - if
the pop is the type of crackle caused by arcing within the mains switch.

If there is a short delay then a thump then you'll need to advise your
friend to either look in JAYCAR / DSE etc. for a speaker protector /
de-thump kit, or he'll need to get a tech to fix the actual fault -
presuming that the amp has not always made a thump (which could be a
design
flaw).

Isn't Usenet wonderful - WR
Click to expand...
 
Trying to help people is often a waste of time.
Like unsolicited advice, not welcomed nor appreciated.

Ross

"Wayne Reid" <REMOVEgokangas@hotmail.com> wrote in message
news:MmWXb.1467$KS1.58475@nasal.pacific.net.au...
"mrocus" <silent@example.com> wrote in message
news:40277dd7$1@news.comindico.com.au...
Had a call from a friend in QLD, one of the amps in his studio setup
makes
a
popping sound when it is turned off.
He has 5 amplifiers same manufacturer, 4 are okay.

I have been out the repair business for a number of years, so I am abit
rusty these days. The grey hair and the grey matter don't help - G!

Any suggestions on a fix. or where to look

He has just sent me a circ diag, blimey these amps are old, they are in
an
electronic organ installation.

Unlike the other posters, I thought Phil's original comment was
reasonable.
But, I'll presume that the fault is not that the amp makes a popping sound
while it is powered off (as described) but rather, a pop or thump is heard
from the speaker at the time the power switch is turned off or shortly
afterwards.

Believe it or not, an ambiguous fault description is likely to generate a
lot of faulty diagnosis from an NG like this one.

Also, your own description of the diagnostics that you would have
performed
are a bit sus. When you ask people for help, don't make like you actually
know the answer or at least you could find it if only...

Take a look at http://www.diyaudio.com/forums/showthread/t-5678.html where
there is a reasonable description of two possible faults that could cause
the symptom you described. There is a description of one possible fix - if
the pop is the type of crackle caused by arcing within the mains switch.

If there is a short delay then a thump then you'll need to advise your
friend to either look in JAYCAR / DSE etc. for a speaker protector /
de-thump kit, or he'll need to get a tech to fix the actual fault -
presuming that the amp has not always made a thump (which could be a
design
flaw).

Isn't Usenet wonderful - WR
Click to expand...
 
On 2004-02-17, mrocus <silent@example.com> wrote:

[...]
When a customer rings up and says that the coffee holder in her PC is
broken, what are you going to think - :)-)))??
Don't drink coffee?
Click to expand...
Don't laugh, I've had one of those.

--
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GIT d- s: a--- C+++ UL++++ UB+++ P+ L++ W+ N++
w--- PGP++ t+ 5++ X++ tv b DI+ D++
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