After more than 20 years, my faithful companion is now making noises on some CDs.
These scratching noises (see attachment mp3) are only present on the analog output, everything is OK on the optical SPDIF.
What could be the reason, has anyone had a similar experience?
Any guesses as to possible causes?
These scratching noises (see attachment mp3) are only present on the analog output, everything is OK on the optical SPDIF.
What could be the reason, has anyone had a similar experience?
Any guesses as to possible causes?
Attachments
Unfortunately the only way I know of finding these (there may be more than one and defective in more than one way - loss of capacitance, occasional leakage etc) is solderng them out and measuring them with a cheap LCR T4 type meter (search eBay). It is a cheap device but shows loss of capacitance and ESR increase pretty well.
Or you can save yourself some time and replace all these decoupling and signal path lytics in DAC and analog output stage in one pass. These small lytics do not cost that much to think twice.
After you get the player into working condition then you can start thinking of improvements by different mods etc.
Or you can save yourself some time and replace all these decoupling and signal path lytics in DAC and analog output stage in one pass. These small lytics do not cost that much to think twice.
After you get the player into working condition then you can start thinking of improvements by different mods etc.
huggygood, thank you for your efforts, I already found the circuit diagram.
I will next look at the signals at the specified test points.
The strange behavior also consists in the fact that these noises occur at the analogue output only with some CDs.
I will next look at the signals at the specified test points.
The strange behavior also consists in the fact that these noises occur at the analogue output only with some CDs.
The problem exists with many of my CDs, all originals, not self-burned.
The noise occurs every time when playing.
The CDs are OK, no problems playing on another device or on the PC.
There are also no problems with the optical SPDIF output.
The noise occurs every time when playing.
The CDs are OK, no problems playing on another device or on the PC.
There are also no problems with the optical SPDIF output.
You should be able to follow the signal from the DAC out to the line out with an osciloscope if it is an analog problem, like a dryed out capacitor..
If it is heard on both channels it may be a problem with the power supply to the analog stages.
If you don't find it there, which means the signal comes distorted from the DAC, it may be a problem with the digital part / error correction.
A new laser should be in the 20$ range, if it is at its end of life, which depends on use and age, maybe just change it. Different disc's have different reflection properties, the laser may be to weak for some. If you have good mechanical skills, this is an easy task. Take the time to view some tutorials before starting, it is the best way to prevent brocken parts while disasembling.
If it is heard on both channels it may be a problem with the power supply to the analog stages.
If you don't find it there, which means the signal comes distorted from the DAC, it may be a problem with the digital part / error correction.
A new laser should be in the 20$ range, if it is at its end of life, which depends on use and age, maybe just change it. Different disc's have different reflection properties, the laser may be to weak for some. If you have good mechanical skills, this is an easy task. Take the time to view some tutorials before starting, it is the best way to prevent brocken parts while disasembling.
I changed all the electrolytic capacitors from the DAC and the analog amplifier stage, unfortunately without success.
Something I noticed, it's all CDs with a very high level that cause these problems.
I will probably continue to use only the optical output and look for a new device.
Thank you for your efforts and replies.
Something I noticed, it's all CDs with a very high level that cause these problems.
I will probably continue to use only the optical output and look for a new device.
Thank you for your efforts and replies.
In many cases the first diagnose of a poster is not 100% perfect.
Also, I'm not sure if all DAC's handle data that may be corrupted the same way. Peronaly I have cured very different problems that CD player had,just by installing new lasers. With laser heads often available for less than 10€ this is not a great financial risk. At least, this is a hobby and you like fixing things if you engage in such repairs. I found the main cause of CD failures to be torn or hardened transport belts, followed by worn laser heads. Most other parts, even of very old players, seem to be very robust. As the electronics do not need to supply high currents, they seem to last very long.
Often a DAC chip failure results in noises like that. It happened to me with TDA1541 and PCM63 dacs .
Do you also have these scratchy noises on the headphone output also? And it's common to both L and R channels?
Thanks for the tip.
The scratchy noises are on both channels.
Unfortunately, I don't have headphones with a large jack plug.
I will get or solder a 3.5 to 5 mm adapter and try a test with the headphones from the cell phone.
I've already closed the issue and bought a new player. The old one has done a good job over the years.
The scratchy noises are on both channels.
Unfortunately, I don't have headphones with a large jack plug.
I will get or solder a 3.5 to 5 mm adapter and try a test with the headphones from the cell phone.
I've already closed the issue and bought a new player. The old one has done a good job over the years.
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Since it's common on L-R and the digital outputs still work, I would start looking at the 5V regulator to the DAC, the DAC chip itself, and then the +/-12V regs.
But if you don't use the headphone jack, you should just use one of the digital outputs and a decent DAC. I'm using a Khadas Tone Board for my recently acquired CD-67SE...
But if you don't use the headphone jack, you should just use one of the digital outputs and a decent DAC. I'm using a Khadas Tone Board for my recently acquired CD-67SE...
Check +12V and -12V in OP-AMP and HDAM Zone.
The problem is in the circuits following the DAC. Digital looks to be right. The sound saturates in some musical passages, it sounds like the OP-AMPs are working bad, but, if are booth channels, the problem is common to all the circuit, so, as I said, check common parts, +12V and -12V power voltages in OP-AMPs and "HDAM" zone, in page 13. Good luck.
The problem is in the circuits following the DAC. Digital looks to be right. The sound saturates in some musical passages, it sounds like the OP-AMPs are working bad, but, if are booth channels, the problem is common to all the circuit, so, as I said, check common parts, +12V and -12V power voltages in OP-AMPs and "HDAM" zone, in page 13. Good luck.