I've acquired this CDP-X303ES piece of wonder and the sound shocked me to the core in a positive way...ODAC goes to the trash or maybe gets a second chance with a USB isolator, will see. 😀
Unfortunately, a few discs have a very audible stutter and its "rhythm" seems to match the laser lens movement. The lens is not moving up and down, but sideways - towards and away from the spindle (or maybe the opposite direction, it's very hard to tell). One disc is jittery throughout all songs, a few only in the end. Others are completely fine including all CD-Rs I threw at it.
I took off the metal laser lid that reveals the lens movement coils and it was surprisingly clean inside so I don't believe there's any dust between the laser sensor and the middle lens, more so because that cavity seems pretty closed off.
So, I lubricated the motor with sewing machine oil (both bearings) and the linear bearing (molybdenum disulfide grease) which didn't make any difference. Also fiddled with spindle height - found a spot where it stutters the least on that particular disc.
Then I took the mechanism apart, so I could better see what the laser is doing during playback and noticed that the playback improves significantly if I tilt it so that the gravity pulls the laser assembly away from the spindle (towards the last track of CD). The stutter transitions to jitter sound, then it becomes inaudible once I find the right angle. Same improvement if I gently push the laser assembly with my finger (keeping the mechanism flat) to mimic the gravity's effect. Once I return it to flat position, or release my finger, the stutter returns.
I can see that somebody has fiddled with TB and FB pots (not me, I promise) - the plastic has screwdriver marks. Thankfully, doesn't seem like they touched APC. TB has the strongest mutilation marks...
I attach an audio sample (1st song of the disc that's jittery throughout). It starts with the mechanism in flat position. On the 18th second I start to tilt it and play with it until the jitter almost disappears. On the 41st second I return the mechanism to the flat position, the sound cuts out for a while, then returns with the jitter.
I have a digital oscilloscope, multimeter and half a brain when it comes to fiddling with delicate mechanisms... So given these clues, what are your first thoughts?
Unfortunately, a few discs have a very audible stutter and its "rhythm" seems to match the laser lens movement. The lens is not moving up and down, but sideways - towards and away from the spindle (or maybe the opposite direction, it's very hard to tell). One disc is jittery throughout all songs, a few only in the end. Others are completely fine including all CD-Rs I threw at it.
I took off the metal laser lid that reveals the lens movement coils and it was surprisingly clean inside so I don't believe there's any dust between the laser sensor and the middle lens, more so because that cavity seems pretty closed off.
So, I lubricated the motor with sewing machine oil (both bearings) and the linear bearing (molybdenum disulfide grease) which didn't make any difference. Also fiddled with spindle height - found a spot where it stutters the least on that particular disc.
Then I took the mechanism apart, so I could better see what the laser is doing during playback and noticed that the playback improves significantly if I tilt it so that the gravity pulls the laser assembly away from the spindle (towards the last track of CD). The stutter transitions to jitter sound, then it becomes inaudible once I find the right angle. Same improvement if I gently push the laser assembly with my finger (keeping the mechanism flat) to mimic the gravity's effect. Once I return it to flat position, or release my finger, the stutter returns.
I can see that somebody has fiddled with TB and FB pots (not me, I promise) - the plastic has screwdriver marks. Thankfully, doesn't seem like they touched APC. TB has the strongest mutilation marks...
I attach an audio sample (1st song of the disc that's jittery throughout). It starts with the mechanism in flat position. On the 18th second I start to tilt it and play with it until the jitter almost disappears. On the 41st second I return the mechanism to the flat position, the sound cuts out for a while, then returns with the jitter.
I have a digital oscilloscope, multimeter and half a brain when it comes to fiddling with delicate mechanisms... So given these clues, what are your first thoughts?
If anyone has tamperred with the laser voltage, purchase a new laser assembly unless you have a laser power meter and are familiar with the set up procedure.
When playing a disk, listen to the laser coils. Adjust the Tracking Gain until it squeals and back it off very slightly, then the Focus Gain likewise. If you cannot get the jitter to stop, replace the laser assembly, they centre position or near it is best. If you can find one as they were obsolete in 1998.
When playing a disk, listen to the laser coils. Adjust the Tracking Gain until it squeals and back it off very slightly, then the Focus Gain likewise. If you cannot get the jitter to stop, replace the laser assembly, they centre position or near it is best. If you can find one as they were obsolete in 1998.
The laser voltage pot looks like new, compared to the other 2 that have clear screwdriver marks.
Actually, replacement KSS-272As has been a worldwide problem for a while, even fixing them... So I will attempt the squeal reduction procedure as suggested, thanks.
Actually, replacement KSS-272As has been a worldwide problem for a while, even fixing them... So I will attempt the squeal reduction procedure as suggested, thanks.
I would say tracking gain is off-centered, your pots indicate that. Tracking is divided in two steps, the lens does the fine tracking, the linear motor does the coarse tracking. The narrower linear track has the sensor coil that gives feedback on where the assemblies` position is. Maybe something is mismatched there and the previous owner tried to compensate. Chack hoow far you can go with the tracking gain pot in both directions
and then find it´s center. Should be a good start for aligning. In case you do not know here is the service manual:
SONY CDP-X303ES SM Service Manual download, schematics, eeprom, repair info for electronics experts
and then find it´s center. Should be a good start for aligning. In case you do not know here is the service manual:
SONY CDP-X303ES SM Service Manual download, schematics, eeprom, repair info for electronics experts
If you have access to a good 'scope, check the eye pattern, page 5 of the service manual, for a clean cross section. Fine adjustment of the focus gain can be set with a 'scope.
⭐⭐⭐⭐⭐
Converted the CDP to a USB DAC with the help of the I2SoverUSB III and some AVR microcontroller magic 😉
Words fail to describe the sound... It's exquisite!
I'll sell my pickup to whomever is interested.
Converted the CDP to a USB DAC with the help of the I2SoverUSB III and some AVR microcontroller magic 😉
Words fail to describe the sound... It's exquisite!
I'll sell my pickup to whomever is interested.
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Hi! better late than never. My first KSS had this problem. I don't know why this issue happens, maybe the plastic is deformed by time, maybe the lens is not exactly at 90º respect the disc...
The most important is that issue can be solved. I tell you how:
Conect an oscilloscope to the RF signal, use a 10x attenuator probe, don't connect with a 1x attenuator because RF signal is deformed.
Put a CD and play it. Move with the finger the laser to the center or to out. If the signal gain signa when you move the laser pickup to the center or to out, you have to adjust the lens position. I don't have miracle solution but here is my solution:
Remove the black cover of the lens, there are two screws.
Then you see that the lens are tied with two little torx screws.
Unscrew these screws, remove the glue if it block the lens soport.
Then, you have to move find the best position to the lens. It is not easy, but you can move seeing the signal playing a disc with the lasts tracks. You can do it with me method prove-error and anoting the place where the best RF signal is obtained.
The way to know if you have obtained the best position is to playing a cd and to moving the laser pickup to the center and out, and observe that now is centered to the best signal, that when yo move the laser pickup to the center or to out the signal get worse.
If you are delicate and don't force anything, that's all. But maybe you moved the vertical adjust, and who knows if you have to adjust the vertical adjust with the other torx screws that are underneath. You'll need a FFC cable extender.
Maybe you'll have to adjust the TB Tracking Balance, but with prove error method you can find a good point in the potentiometer adjust.
I tried to do this adjust moving the lens until to get the maximum laser power, but it did not worked.
And I know, it is don't easy. But is fun for those who like this stuff.
The most important is that issue can be solved. I tell you how:
Conect an oscilloscope to the RF signal, use a 10x attenuator probe, don't connect with a 1x attenuator because RF signal is deformed.
Put a CD and play it. Move with the finger the laser to the center or to out. If the signal gain signa when you move the laser pickup to the center or to out, you have to adjust the lens position. I don't have miracle solution but here is my solution:
Remove the black cover of the lens, there are two screws.
Then you see that the lens are tied with two little torx screws.
Unscrew these screws, remove the glue if it block the lens soport.
Then, you have to move find the best position to the lens. It is not easy, but you can move seeing the signal playing a disc with the lasts tracks. You can do it with me method prove-error and anoting the place where the best RF signal is obtained.
The way to know if you have obtained the best position is to playing a cd and to moving the laser pickup to the center and out, and observe that now is centered to the best signal, that when yo move the laser pickup to the center or to out the signal get worse.
If you are delicate and don't force anything, that's all. But maybe you moved the vertical adjust, and who knows if you have to adjust the vertical adjust with the other torx screws that are underneath. You'll need a FFC cable extender.
Maybe you'll have to adjust the TB Tracking Balance, but with prove error method you can find a good point in the potentiometer adjust.
I tried to do this adjust moving the lens until to get the maximum laser power, but it did not worked.
And I know, it is don't easy. But is fun for those who like this stuff.