Got an interesting fault on a Denon DN-650F pro CD player. The XLR outputs
are fine - but both the phono and headphone outlets topless - although
level seems normal. And all three are in parallel except for a 680 ohm
resistor in series with the lines to the phonos and headphone outlet. I'm
guessing it is something to do with the muting circuits - which seem to be
separate for each output pairs. A relay for the XLR ones, transistors
which short the lines for the phono, and a couple of op amps for the
headphone one. Talk about complicated. ;-)

--
*I have a degree in liberal arts -- do you want fries with that

Dave Plowman London SW
To e-mail, change noise into sound.

Does seem od when a multi pole relay might have done the same job.


I have a Marantz cd player here which is having troubles finding the next
track when this is manually selected. Its worse on home made cds, but can
still happen on normal ones, it jiggles for what seeems a very short period
then gives up showing the word error in the display, I'm told.
It also skips about on cdrws which it played fine previously.


Maybe the laser is wearing out or the mechanics are sticky. Hard to tell.
Brian

--
From the Sofa of Brian Gaff Reply address is active
"Dave Plowman (News)" wrote in message
...
Got an interesting fault on a Denon DN-650F pro CD player. The XLR outputs
are fine - but both the phono and headphone outlets topless - although
level seems normal. And all three are in parallel except for a 680 ohm
resistor in series with the lines to the phonos and headphone outlet. I'm
guessing it is something to do with the muting circuits - which seem to be
separate for each output pairs. A relay for the XLR ones, transistors
which short the lines for the phono, and a couple of op amps for the
headphone one. Talk about complicated. ;-)

--
*I have a degree in liberal arts -- do you want fries with that

Dave Plowman London SW
To e-mail, change noise into sound.

On 25/11/14 16:26, Brian Gaff wrote:

Maybe the laser is wearing out or the mechanics are sticky. Hard to tell.

Have you cleaned the LASER head by hand (not one of those CD cleaners
you play in the drive)? It is possible a very thin film over years is
clouding it making tracking harder.

In article ,
Ar wrote:
On 25/11/14 16:26, Brian Gaff wrote:

Maybe the laser is wearing out or the mechanics are sticky. Hard to
tell.

Have you cleaned the LASER head by hand (not one of those CD cleaners
you play in the drive)? It is possible a very thin film over years is
clouding it making tracking harder.

How would that affect the sound from the phono outputs but not the
balanced ones?

--
*Husbands should come with instructions

Dave Plowman London SW
To e-mail, change noise into sound.

On 26/11/2014 16:43, Dave Plowman (News) wrote:
In article ,
Ar wrote:
On 25/11/14 16:26, Brian Gaff wrote:

Maybe the laser is wearing out or the mechanics are sticky. Hard to
tell.

Have you cleaned the LASER head by hand (not one of those CD cleaners
you play in the drive)? It is possible a very thin film over years is
clouding it making tracking harder.

How would that affect the sound from the phono outputs but not the
balanced ones?

Ar seems to have been offering a solution to Brian's problem, not yours.

As for your problem, you say the levels are normal, but there's an HF
loss on two of the outputs?

--
Tciao for Now!

John.

In article ,
John Williamson wrote:
On 26/11/2014 16:43, Dave Plowman (News) wrote:
In article ,
Ar wrote:
On 25/11/14 16:26, Brian Gaff wrote:

Maybe the laser is wearing out or the mechanics are sticky. Hard to
tell.

Have you cleaned the LASER head by hand (not one of those CD cleaners
you play in the drive)? It is possible a very thin film over years is
clouding it making tracking harder.

How would that affect the sound from the phono outputs but not the
balanced ones?

Ar seems to have been offering a solution to Brian's problem, not yours.

As for your problem, you say the levels are normal, but there's an HF
loss on two of the outputs?

That's about it. Severe HF loss. I'm thinking it may be down to the muting
circuits being partially activated. They are electronic on the two that
are affected - but a relay on the balanced ones. So it is either on or off.

--
*It was recently discovered that research causes cancer in rats*

Dave Plowman London SW
To e-mail, change noise into sound.

On 27/11/2014 00:10, Dave Plowman (News) wrote:
In article ,
John Williamson wrote:
On 26/11/2014 16:43, Dave Plowman (News) wrote:
In article ,
Ar wrote:
On 25/11/14 16:26, Brian Gaff wrote:

Maybe the laser is wearing out or the mechanics are sticky. Hard to
tell.

Have you cleaned the LASER head by hand (not one of those CD cleaners
you play in the drive)? It is possible a very thin film over years is
clouding it making tracking harder.

How would that affect the sound from the phono outputs but not the
balanced ones?

Ar seems to have been offering a solution to Brian's problem, not yours.

As for your problem, you say the levels are normal, but there's an HF
loss on two of the outputs?

That's about it. Severe HF loss. I'm thinking it may be down to the muting
circuits being partially activated. They are electronic on the two that
are affected - but a relay on the balanced ones. So it is either on or off.

It's possibly too obvious, but have you checked the 680R resistors for
high values and any capacitors for shorts? Or even a leaky connection/
switch on the switching inputs?

I've found a circuit online, but they want me to pay for it....

--
Tciao for Now!

John.

Hard to get at the laser lens in this model. It seems to be inside a plastic
sleeve wher the drawer goes in.

Brian

--
From the Sofa of Brian Gaff Reply address is active
"Ar" wrote in message ...
On 25/11/14 16:26, Brian Gaff wrote:

Maybe the laser is wearing out or the mechanics are sticky. Hard to tell.

Have you cleaned the LASER head by hand (not one of those CD cleaners you
play in the drive)? It is possible a very thin film over years is clouding
it making tracking harder.