Hi Everyone,
My modded CD 104 works like a charm, except that during playback a clicking noise can be heard. (from line out, not mechanical clicking).
The clicking sounds like tapping on a table with your fingernails, only a little bit muffled (I hope that makes sense...)
Sometimes it can be heard from both speakers at the same time, and sometimes only from one channel.
It does not appear regurlarly, but seemingly in a random pattern.
Interestingly it occurs reproducably at the same positions of a track, so it is not random. (double checked with my other player, the CDs are OK and not scratched)
Initially the sound was not there, it appeared after I changed the PS Caps and the OpAmps, added caps at the Power supply of Opamps and DACs and resoldered many connections.
Unfortunately I dont know after which modification the clicking started, because I only made a quick listening test after each mod.
I removed all mods and the error is still there.
Before the mods, I recreated the Ground Vias on the PCBs as often recommended here.
It worked without problems then.
I hope someone has an idea how I can track down the cause.
Thanks in advance
mabu
My modded CD 104 works like a charm, except that during playback a clicking noise can be heard. (from line out, not mechanical clicking).
The clicking sounds like tapping on a table with your fingernails, only a little bit muffled (I hope that makes sense...)
Sometimes it can be heard from both speakers at the same time, and sometimes only from one channel.
It does not appear regurlarly, but seemingly in a random pattern.
Interestingly it occurs reproducably at the same positions of a track, so it is not random. (double checked with my other player, the CDs are OK and not scratched)
Initially the sound was not there, it appeared after I changed the PS Caps and the OpAmps, added caps at the Power supply of Opamps and DACs and resoldered many connections.
Unfortunately I dont know after which modification the clicking started, because I only made a quick listening test after each mod.
I removed all mods and the error is still there.
Before the mods, I recreated the Ground Vias on the PCBs as often recommended here.
It worked without problems then.
I hope someone has an idea how I can track down the cause.
Thanks in advance
mabu
Would you describe the sound as purely popping or is it a bit scratchy?
Does it appear only on one specific CD or on different ones?
Does it follow the spinning sped of disc?
Most likely it is a tracking error. Either you misaligned the servo during the overhaul and need to readjust it, or you accidentally reversed the polarity of a cap in servo circuit or in CDM assembly.
Does it appear only on one specific CD or on different ones?
Does it follow the spinning sped of disc?
Most likely it is a tracking error. Either you misaligned the servo during the overhaul and need to readjust it, or you accidentally reversed the polarity of a cap in servo circuit or in CDM assembly.
Hello,
Thanks for all the suggestions,
attached is a short recording of the output of my CD 104.
I first had the association that someone is tapping against my headphone with his fingernail, that is how I would describe the noise.
It appears on all CDs played, but only on passages with medium or high volume.
For testing I burnt a CD with only silence on it. Playing it, there were no distortions or noise at all...
The noise is the same at the end of the disc.
When the distortions started, I had only worked on the decoder board and the PS, on the servo board I only did the griplets. The other boards I did not work on.
I resoldered all griplets again, even the ones with a capacitor lead through them. (directly after receiving the player I already desoldered the griplets, drilled through them and resoldered with a piece of wire through them).
@Jon Snell:
Do you mean to replace the pins of the connectors that link the boards?
btw, I checked the voltages of the PS, they are all OK, with a maximum deviation of -0.15 V.
Thank you for your ideas..
mabu
Thanks for all the suggestions,
attached is a short recording of the output of my CD 104.
I first had the association that someone is tapping against my headphone with his fingernail, that is how I would describe the noise.
It appears on all CDs played, but only on passages with medium or high volume.
For testing I burnt a CD with only silence on it. Playing it, there were no distortions or noise at all...
The noise is the same at the end of the disc.
When the distortions started, I had only worked on the decoder board and the PS, on the servo board I only did the griplets. The other boards I did not work on.
I resoldered all griplets again, even the ones with a capacitor lead through them. (directly after receiving the player I already desoldered the griplets, drilled through them and resoldered with a piece of wire through them).
@Jon Snell:
Do you mean to replace the pins of the connectors that link the boards?
btw, I checked the voltages of the PS, they are all OK, with a maximum deviation of -0.15 V.
Thank you for your ideas..
mabu
This sounds like the famous "woodpecker" beats from Soviet over-the-horizon radar installations which once could be picked in AM range 🙂
From your sound clip, the only corelation between clicking and music I see is that it occurs when there is music. It does not seem to depend on amplitude but it may happen in presence of multiple frequencies.
I would experiment with white noise and a couple of test signals burned to a test CD in order to see if the click occurs with steady amplitude signals. Another thing to verify is if you can hear laser transport very faintly doing jumping or correcting the tracking when it comes to the clicking part of the CD track.
From your sound clip, the only corelation between clicking and music I see is that it occurs when there is music. It does not seem to depend on amplitude but it may happen in presence of multiple frequencies.
I would experiment with white noise and a couple of test signals burned to a test CD in order to see if the click occurs with steady amplitude signals. Another thing to verify is if you can hear laser transport very faintly doing jumping or correcting the tracking when it comes to the clicking part of the CD track.
I've never come across anything like that. Loading the track into Audacity shows the noise and it seems centred on 300Hz.
For no good reason I just wonder whether it is a problem with the DAC or something closely related in the processing chain. Glitches and error correction or faulty RAM issues just don't sound like that.
Baffled on that one 🙂
For no good reason I just wonder whether it is a problem with the DAC or something closely related in the processing chain. Glitches and error correction or faulty RAM issues just don't sound like that.
Baffled on that one 🙂
Attachments
I think I can rule out East-European radar installations, havent't seen any of them around my flat ;-)
I downloaded some test files and will burn them tomorrow.
I am planning to replace the coupling SMD capacitors at the Dacs, can someone please send me the service manual in good quality?
On mine I cannot read most of the part names and values.
I downloaded some test files and will burn them tomorrow.
I am planning to replace the coupling SMD capacitors at the Dacs, can someone please send me the service manual in good quality?
On mine I cannot read most of the part names and values.
This is the best quality I have:
http://we.tl/ckU52jVP2E
I also included a modder's 5-page guide. Perhaps you will also want to take a look at this page:
~ Classic CD Player Modification & Modernisation ~
I wouldn't make any more interventions before discovering the cause / repairing the poking headphone noise.
http://we.tl/ckU52jVP2E
I also included a modder's 5-page guide. Perhaps you will also want to take a look at this page:
~ Classic CD Player Modification & Modernisation ~
I wouldn't make any more interventions before discovering the cause / repairing the poking headphone noise.
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