I bought this Yamaha Receiver R-9 at a garage sale, it sounds great (
way better than my more recent Technics receiver) and has a lot of
features. However, it produces a humming sound on one of the speakers,
which is drowned by the music once it is played. The sound has peaks
and valleys, kinda like a windy day.
The unit is very dusty inside, should I blow some air in it or not?
Thanks for the answers.

Most likely the main filter capacitors, and the decoupler capacigtors
probably have to be changed in the power supply section. It is also
possible that there are other components and capacitors in the set that
have to be changed because of their age. This is common in these sets.

If you are not experienced in servicing electronic equipment, you
should give the reciever out for proper service. There are also serious
safety issues with servicing electronic equipment.


Jerry G.
======

"Jerry G." wrote in message
ups.com...
Most likely the main filter capacitors, and the decoupler capacigtors
probably have to be changed in the power supply section. It is also
possible that there are other components and capacitors in the set that
have to be changed because of their age. This is common in these sets.

If you are not experienced in servicing electronic equipment, you
should give the reciever out for proper service. There are also serious
safety issues with servicing electronic equipment.


Jerry G.
======

As far as I recall, the power supply on these is common to all channels,
thus if the hum is on one channel only, it is highly unlikely that it is
being caused by the main smoothing caps. The first thing to establish is if
the hum is affected by the setting of the volume control. If it is, then the
problem will likely be a front-end grounding issue. Any power supply problem
will normally not have the symptoms it's causing, affected by the volume
setting, and will affect all channels equally.

Arfa

"Jamie" t wrote in message
...
Arfa Daily wrote:

"Jerry G." wrote in message
ups.com...

Most likely the main filter capacitors, and the decoupler capacigtors
probably have to be changed in the power supply section. It is also
possible that there are other components and capacitors in the set that
have to be changed because of their age. This is common in these sets.

If you are not experienced in servicing electronic equipment, you
should give the reciever out for proper service. There are also serious
safety issues with servicing electronic equipment.


Jerry G.
======


As far as I recall, the power supply on these is common to all channels,
thus if the hum is on one channel only, it is highly unlikely that it is
being caused by the main smoothing caps. The first thing to establish is
if the hum is affected by the setting of the volume control. If it is,
then the problem will likely be a front-end grounding issue. Any power
supply problem will normally not have the symptoms it's causing, affected
by the volume setting, and will affect all channels equally.

Arfa
many high end audio amps have their own bridges and caps per channel,
they may use the same xformer how ever.


--
Real Programmers Do things like this.
http://webpages.charter.net/jamie_5

Agreed, but as I said, I seem to recall that this Yammy has a common power
supply.

Arfa

Arfa Daily wrote:

"Jerry G." wrote in message
ups.com...

Most likely the main filter capacitors, and the decoupler capacigtors
probably have to be changed in the power supply section. It is also
possible that there are other components and capacitors in the set that
have to be changed because of their age. This is common in these sets.

If you are not experienced in servicing electronic equipment, you
should give the reciever out for proper service. There are also serious
safety issues with servicing electronic equipment.


Jerry G.
======


As far as I recall, the power supply on these is common to all channels,
thus if the hum is on one channel only, it is highly unlikely that it is
being caused by the main smoothing caps. The first thing to establish is if
the hum is affected by the setting of the volume control. If it is, then the
problem will likely be a front-end grounding issue. Any power supply problem
will normally not have the symptoms it's causing, affected by the volume
setting, and will affect all channels equally.

Arfa


many high end audio amps have their own bridges and caps per channel,
they may use the same xformer how ever.


--
Real Programmers Do things like this.
http://webpages.charter.net/jamie_5

Arfa Daily wrote:

======

As far as I recall, the power supply on these is common to all channels,
thus if the hum is on one channel only, it is highly unlikely that it is
being caused by the main smoothing caps. The first thing to establish is if
the hum is affected by the setting of the volume control. If it is, then the
problem will likely be a front-end grounding issue.

thanks for the answers, but what is a front end grounding issue?
Excuse my ignorance, I am starting to pick up these old receivers for
few dollars, and I am amazed by the sound quality ( I also have a
small, old Sansui R-606 that sounds incredible), and I want to learn
the basics.
I think I have a new hobby.

On Sun, 21 May 2006 18:45:28 GMT, "David" put
finger to keyboard and composed:

Arfa, what is a "Yammy"?

David

It's kinda like a Kwaka but with less horsepower.

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

NOT the R-9 .... it has a single power supply for both channels and if
it is bad then both channels would be affected.
Look for loose grounds, leaky driver or preamp transistors, etc.
Fortunately when servicing stereo equipment you have a fully redundant
and duplicate channel for comparison tests and even temporary component
swapping to verify problems.
electricitym

"David" wrote in message
. com...
Agreed, but as I said, I seem to recall that this Yammy has a common
power
supply.

Arfa



Arfa, what is a "Yammy"?

David


It's 'trade speak' for a product from the Yamaha stable. Like calling a
Panasonic a "Pan". Just lazy slang I guess. I was referring to the OP's
question which referenced a specific Yamaha model

Arfa

wrote in message
oups.com...
NOT the R-9 .... it has a single power supply for both channels and if
it is bad then both channels would be affected.
Look for loose grounds, leaky driver or preamp transistors, etc.
Fortunately when servicing stereo equipment you have a fully redundant
and duplicate channel for comparison tests and even temporary component
swapping to verify problems.
electricitym


Heg-zackerly !! That's just what I said. Thanks for the backup ...

Arfa

"punkinaro" wrote in message
oups.com...

Arfa Daily wrote:

======

As far as I recall, the power supply on these is common to all channels,
thus if the hum is on one channel only, it is highly unlikely that it is
being caused by the main smoothing caps. The first thing to establish is
if
the hum is affected by the setting of the volume control. If it is, then
the
problem will likely be a front-end grounding issue.

thanks for the answers, but what is a front end grounding issue?
Excuse my ignorance, I am starting to pick up these old receivers for
few dollars, and I am amazed by the sound quality ( I also have a
small, old Sansui R-606 that sounds incredible), and I want to learn
the basics.
I think I have a new hobby.


OK. 'Front end' is engineer speak for the input select / preamp / tone
control etc stages of an amplifier, and is generally accepted as being any
and all of the circuitry from the input sockets, as far as the volume
control. After the volume control is usually taken to be 'output stage' or
'power amp', and the actual circuitry will include predriver, driver, and
output stages.

If you connect a signal to an amplifier, with the ground disconnected,
there's a good chance that the amp will produce a loud hum, which can be
controlled by the volume setting. This tells you that the problem is 'front
end' related. The results of bad ground connections internal to an amplifier
can vary depending on the exact design and layout, but if, for instance, the
ground pin of an input socket went dry jointed in the board, or sheared
off - both common failures - you may well still get correct audio through
the channel, due to the ground connection being intact on the other channel,
but you may also get a degree of hum on the 'bad' channel, due to the ground
following an abnormal path via the other channel.

If you have a hum which is not affected by the volume control, then this
indicates that the problem is post the volume control, OR is power supply
related. As noted by myself and electricitym, a power supply related problem
will, in most cases, affect both channels, as a common power supply is
typically used to supply both channels. The exception to this occurs in a
few high-end amps, which employ separate power supplies for each amplifier.
You can think of these amps really, as being two independant mono amps built
on the same chassis, but with ganged controls. Your Yamaha employs a single
common power supply, which is why I said that if you have hum on one channel
only, the problem is *unlikely* to be power supply related. Hope this helps
you to understand it a bit better. It's easy for those of us who work on the
stuff all day, to forget that many people asking questions on here are
either amateur, or just starting out.

Arfa

In one sense you are absolutely right. Jerry G. must have missed on that
one. But, some of
these receivers also used a split power supply. I cannot say for sure with
his model.


--

JANA
_____


"Arfa Daily" wrote in message
...

"Jerry G." wrote in message
ups.com...
Most likely the main filter capacitors, and the decoupler capacigtors
probably have to be changed in the power supply section. It is also
possible that there are other components and capacitors in the set that
have to be changed because of their age. This is common in these sets.

If you are not experienced in servicing electronic equipment, you
should give the reciever out for proper service. There are also serious
safety issues with servicing electronic equipment.


Jerry G.
======

As far as I recall, the power supply on these is common to all channels,
thus if the hum is on one channel only, it is highly unlikely that it is
being caused by the main smoothing caps. The first thing to establish is if
the hum is affected by the setting of the volume control. If it is, then the
problem will likely be a front-end grounding issue. Any power supply problem
will normally not have the symptoms it's causing, affected by the volume
setting, and will affect all channels equally.

Arfa

This confirms a separate set of filter caps for each side. The thing here,
is that someone would have to know the specific model design, or have it
opened on their service bench in order to even start making assumptions of
what the fault may be.

--

JANA
_____


"Jamie" t wrote in message
...
Arfa Daily wrote:

"Jerry G." wrote in message
ups.com...

Most likely the main filter capacitors, and the decoupler capacigtors
probably have to be changed in the power supply section. It is also
possible that there are other components and capacitors in the set that
have to be changed because of their age. This is common in these sets.

If you are not experienced in servicing electronic equipment, you
should give the reciever out for proper service. There are also serious
safety issues with servicing electronic equipment.


Jerry G.
======


As far as I recall, the power supply on these is common to all channels,
thus if the hum is on one channel only, it is highly unlikely that it is
being caused by the main smoothing caps. The first thing to establish is
if
the hum is affected by the setting of the volume control. If it is, then
the
problem will likely be a front-end grounding issue. Any power supply
problem
will normally not have the symptoms it's causing, affected by the volume
setting, and will affect all channels equally.

Arfa


many high end audio amps have their own bridges and caps per channel,
they may use the same xformer how ever.


--
Real Programmers Do things like this.
http://webpages.charter.net/jamie_5

Does it have a separate set of filter caps, and voltage regulators for each
side???

--

JANA
_____


"Arfa Daily" wrote in message
...

"Jamie" t wrote in message
...
Arfa Daily wrote:

"Jerry G." wrote in message
ups.com...

Most likely the main filter capacitors, and the decoupler capacigtors
probably have to be changed in the power supply section. It is also
possible that there are other components and capacitors in the set that
have to be changed because of their age. This is common in these sets.

If you are not experienced in servicing electronic equipment, you
should give the reciever out for proper service. There are also serious
safety issues with servicing electronic equipment.


Jerry G.
======


As far as I recall, the power supply on these is common to all channels,
thus if the hum is on one channel only, it is highly unlikely that it is
being caused by the main smoothing caps. The first thing to establish is
if the hum is affected by the setting of the volume control. If it is,
then the problem will likely be a front-end grounding issue. Any power
supply problem will normally not have the symptoms it's causing, affected
by the volume setting, and will affect all channels equally.

Arfa
many high end audio amps have their own bridges and caps per channel,
they may use the same xformer how ever.


--
Real Programmers Do things like this.
http://webpages.charter.net/jamie_5

Agreed, but as I said, I seem to recall that this Yammy has a common power
supply.

Arfa

What's a, "Kwaka"???

--

JANA
_____


"Franc Zabkar" wrote in message
...
On Sun, 21 May 2006 18:45:28 GMT, "David" put
finger to keyboard and composed:

Arfa, what is a "Yammy"?

David

It's kinda like a Kwaka but with less horsepower.

- Franc Zabkar
--
Please remove one 'i' from my address when replying by email.

"Heg-zackerly !!"

I love your expressions! Do you have a list???

--

JANA
_____


"Arfa Daily" wrote in message
...

wrote in message
oups.com...
NOT the R-9 .... it has a single power supply for both channels and if
it is bad then both channels would be affected.
Look for loose grounds, leaky driver or preamp transistors, etc.
Fortunately when servicing stereo equipment you have a fully redundant
and duplicate channel for comparison tests and even temporary component
swapping to verify problems.
electricitym


Heg-zackerly !! That's just what I said. Thanks for the backup ...

Arfa

I have worked on high end Crown amplifiers and others along that line. These
are used in professional studio environments. They use a complete set of
power supplies for each channel of audio. Some models only share the same
power transformer, but the rest of the power supply is separate.

If you want to have some very good quality sound, that you cannot experience
with any of the home audio gear, get in to collecting and building up a
sound system using professional audio equipment. There is a big difference!

--

JANA
_____


"Arfa Daily" wrote in message
...

"punkinaro" wrote in message
oups.com...

Arfa Daily wrote:

======

As far as I recall, the power supply on these is common to all channels,
thus if the hum is on one channel only, it is highly unlikely that it is
being caused by the main smoothing caps. The first thing to establish is
if
the hum is affected by the setting of the volume control. If it is, then
the
problem will likely be a front-end grounding issue.

thanks for the answers, but what is a front end grounding issue?
Excuse my ignorance, I am starting to pick up these old receivers for
few dollars, and I am amazed by the sound quality ( I also have a
small, old Sansui R-606 that sounds incredible), and I want to learn
the basics.
I think I have a new hobby.


OK. 'Front end' is engineer speak for the input select / preamp / tone
control etc stages of an amplifier, and is generally accepted as being any
and all of the circuitry from the input sockets, as far as the volume
control. After the volume control is usually taken to be 'output stage' or
'power amp', and the actual circuitry will include predriver, driver, and
output stages.

If you connect a signal to an amplifier, with the ground disconnected,
there's a good chance that the amp will produce a loud hum, which can be
controlled by the volume setting. This tells you that the problem is 'front
end' related. The results of bad ground connections internal to an amplifier
can vary depending on the exact design and layout, but if, for instance, the
ground pin of an input socket went dry jointed in the board, or sheared
off - both common failures - you may well still get correct audio through
the channel, due to the ground connection being intact on the other channel,
but you may also get a degree of hum on the 'bad' channel, due to the ground
following an abnormal path via the other channel.

If you have a hum which is not affected by the volume control, then this
indicates that the problem is post the volume control, OR is power supply
related. As noted by myself and electricitym, a power supply related problem
will, in most cases, affect both channels, as a common power supply is
typically used to supply both channels. The exception to this occurs in a
few high-end amps, which employ separate power supplies for each amplifier.
You can think of these amps really, as being two independant mono amps built
on the same chassis, but with ganged controls. Your Yamaha employs a single
common power supply, which is why I said that if you have hum on one channel
only, the problem is *unlikely* to be power supply related. Hope this helps
you to understand it a bit better. It's easy for those of us who work on the
stuff all day, to forget that many people asking questions on here are
either amateur, or just starting out.

Arfa

"JANA" wrote in message
...
This confirms a separate set of filter caps for each side. The thing here,
is that someone would have to know the specific model design, or have it
opened on their service bench in order to even start making assumptions of
what the fault may be.

--

JANA
_____

How exactly does this confirm a separate set of filter caps for each side ?
Let me say again, as far as I recall, the Yamaha R9 has a single multi-rail
power supply, which feeds everything. It's not a model that I've seen
frequently, so I wasn't absolutely sure about this. However, electricitym
confirmed in his post of the 22nd at 00:10 that this is the case. So, he
does know the specific model, and made all of the same comments in his post,
that I had : viz a single power supply feeding both channels, is unlikely to
be the cause of hum on one channel only, and that front end ground issues
are more likely to be the cause of the problem. I don't really think that
either of us was making assumptions about what is wrong with the equipment.
We were merely offering pointers to the probable fault areas, based on many
years' experience of repairing this stuff commercially.

Also, I don't want to make big issue over it, but top posting does get
confusing for people trying to follow the thread. It sometimes makes it
difficult to follow just exactly which comment you are responding to. The
common convention is to bottom post, which I accept also has its drawbacks,
but if we all stick to the same convention, it makes it easier all round :-)

Glad you like my little words. It injects a bit of light-hearted humour, if
nothing else. I'm surprised you haven't come across " Kwaka ". It's a fairly
world-wide ( I think ) slang term for a Kawasaki motor cycle - hence Franc's
comment about horsepower. d;~}

Arfa

On 21 May 2006 06:16:22 -0700, "punkinaro" wrote:

I bought this Yamaha Receiver R-9 at a garage sale, it sounds great (
way better than my more recent Technics receiver) and has a lot of
features. However, it produces a humming sound on one of the speakers,
which is drowned by the music once it is played. The sound has peaks
and valleys, kinda like a windy day.
The unit is very dusty inside, should I blow some air in it or not?
Thanks for the answers.

Does it get hot?

How does your tweeter look?

The amp may be oscillating. Older yamaha's are slightly famous for
that with certain speakers. The oscillation comes and goes, loading
the amp to the limit without creating much audible sound. When the
oscillation hits rail to rail the hum starts to be noticable. I did
actually witness a tweeter dripping out of the box slowly...

--
- René

I've worked on those, and my memory of the power supply's the same as
Arfa's.

I too would be looking for bad earth connections in the affected
channel. Either that or possibly a dried-out supply decoupling cap
associated with a regulator etc. Or... that atrocious yellow glue
having gone conductive and coupling AC into the signal path.

The main power supply rails always have significant ripple, which is
supposed to be stopped by the regulators feeding the front-end
circuitry.

I thought everyone knew that "Yammy" is short for Yamaha, and "Kwaka"
is a truncation of Kawasaki. It must be applicable only in England and
Australia?

Bob


On Mon, 22 May 2006 01:04:49 -0400, "JANA" wrote:

In one sense you are absolutely right. Jerry G. must have missed on that
one. But, some of
these receivers also used a split power supply. I cannot say for sure with
his model.

René wrote:
On 21 May 2006 06:16:22 -0700, "punkinaro" wrote:

I bought this Yamaha Receiver R-9 at a garage sale, it sounds great (
way better than my more recent Technics receiver) and has a lot of
features. However, it produces a humming sound on one of the speakers,
which is drowned by the music once it is played. The sound has peaks
and valleys, kinda like a windy day.
The unit is very dusty inside, should I blow some air in it or not?
Thanks for the answers.

Does it get hot?

How does your tweeter look?

The amp may be oscillating. Older yamaha's are slightly famous for
that with certain speakers. The oscillation comes and goes, loading
the amp to the limit without creating much audible sound. When the
oscillation hits rail to rail the hum starts to be noticable. I did
actually witness a tweeter dripping out of the box slowly...

it sounds like it might explode anytime :-))
I will check to see if it gets hot, and check the tweeter.
One question : on the back of the receiver there is a "Ground" round
thing. Am I suppose to attach a cable or something else? ( excuse my
lack of proper terms, I sell sweatshirts, I am no technician...)
thanks again, man, you guys are good




--
- René

"punkinaro" wrote in message
oups.com...

René wrote:
On 21 May 2006 06:16:22 -0700, "punkinaro" wrote:

I bought this Yamaha Receiver R-9 at a garage sale, it sounds great (
way better than my more recent Technics receiver) and has a lot of
features. However, it produces a humming sound on one of the speakers,
which is drowned by the music once it is played. The sound has peaks
and valleys, kinda like a windy day.
The unit is very dusty inside, should I blow some air in it or not?
Thanks for the answers.

Does it get hot?

How does your tweeter look?

The amp may be oscillating. Older yamaha's are slightly famous for
that with certain speakers. The oscillation comes and goes, loading
the amp to the limit without creating much audible sound. When the
oscillation hits rail to rail the hum starts to be noticable. I did
actually witness a tweeter dripping out of the box slowly...

it sounds like it might explode anytime :-))
I will check to see if it gets hot, and check the tweeter.
One question : on the back of the receiver there is a "Ground" round
thing. Am I suppose to attach a cable or something else? ( excuse my
lack of proper terms, I sell sweatshirts, I am no technician...)
thanks again, man, you guys are good




--
- René

The " Ground " terminal on the back, is usually for use with a phono deck
( vinyl record playing turntable ). You will normally find on these devices,
a 'standard' stereo screened cable, which is connected at the deck end to
the two channels of the pickup cartridge, and to normal RCA jacks at the amp
end. There is often then a separate wire connected to the main metalwork of
the deck, which runs along in tandem with the screened cable, and terminates
in a fork connector, to go under that ground terminal that you mention.

The function of this wire is to tie the grounded metalwork of the amplifier,
to the metalwork of the deck, thereby grounding it also. Without this
additional ground, the (extremely) sensitive phono inputs will have tendency
to pick up all manner of hum, clicks and pops, particularly when you touch
the tonearm ( which also usually has its own thin groundwire going back to
the main metalwork ) or the start / stop controls etc.

Arfa

On Mon, 22 May 2006 06:37:34 -0400 "JANA" wrote in
Message id: :

What's a, "Kwaka"???

Something you put cheese on.