Well that's a nice problem to have 
Pleased to hear you are enjoying it.
Talking of weird failures...
The second generation budget Sony CDP's (can't remember the number now) were super reliable. They used a chip set similar to the D50mk1 discman with a CX20108 and CX20109.
A company called 'Fidelity' which was a cheap and cheerful high street name produced a separate CD player and it was based on the Sony, pretty much identical circuitry but a different board layout and PSU and we experienced many failures of I think the CX20109 which was the RF amp. Never a reason found but we changed many. Very odd.
Pleased to hear you are enjoying it.Talking of weird failures...
The second generation budget Sony CDP's (can't remember the number now) were super reliable. They used a chip set similar to the D50mk1 discman with a CX20108 and CX20109.
A company called 'Fidelity' which was a cheap and cheerful high street name produced a separate CD player and it was based on the Sony, pretty much identical circuitry but a different board layout and PSU and we experienced many failures of I think the CX20109 which was the RF amp. Never a reason found but we changed many. Very odd.
Would you rank the DCD-2560 as “the best of the best” among Denon models?
I’m expecting that DCD-1500II that I found a month ago to sound really great also. I have gotten it into fully working condition except for shimming the clamper arm to the correct height to avoid rubbing on the magnetic clamper puck.
-EB
Hi Karl,
I was in fact out of the city, thanks. You're right.
Hi EB,
No, the 3560 was better. The DCD-S10 / DCD-3000 has a better D/A stage and the current ones are probably excellent. Having said that, the DCD-2560 is easily better than most. The upper Denon equipment tended to sound a lot better than most other CD players. The gold one I got recently is also an extremely good machine (1630G?).
There is never a simple answer to what is the best. Pros and cons with each one.
I was in fact out of the city, thanks. You're right.
Hi EB,
No, the 3560 was better. The DCD-S10 / DCD-3000 has a better D/A stage and the current ones are probably excellent. Having said that, the DCD-2560 is easily better than most. The upper Denon equipment tended to sound a lot better than most other CD players. The gold one I got recently is also an extremely good machine (1630G?).
There is never a simple answer to what is the best. Pros and cons with each one.
Abother update for my Denon DCM-320 restoration:
It is still operating perfectly after playing 24/7 on “repeat 5 discs” for 2 weeks, confirming the original CXA1372S servo IC was faulty.
And it continues to sound great playing every disc I put into it.
I think I will call this restoration “completed.”
-EB
I'll give that "heat run" test mode a try.
This Denon DCM-320 currently has a new "generic" KSS-240A in it. But I think the original factory pickup is still good. I put the old pickup into a different CD player and it works fine.
Everything points to the fault in this Denon DCM-320 being the failed CXA1372S servo IC:
RE: "Generic" low-cost KSS-240A pickups, here are my observations after installing several:
- If anything they work better than the originals.
- Only one new pickup required adjustment of its trimpots: Its RF level was too low (only 800mV) and the laser current was also quite low (35mA). Raising the laser current to 42mA provided the desired 1.2V of RF.
- These generic pickups rarely skip when tapping on the CD player (even with very robust tapping). In comparison many of the original KSS-240A pickups skip when tapping on the CD player. Perhaps the actuator/lens assembly in the generic pickup has lower mass?
-EB
I've a vague recollection of some service bulletin for KSS240's that mentioned something about lens suspension deteriorating. Something along the lines of that if it passed all electrical tests and the RF was good and yet it still skipped then the suspension was at fault. Lol and that would have been 25 years ago.
Hi Karl,
Wow, I didn't see that notice. The KSS-240A is basically a KSS-210A with the RF amp mounted on the head. I haven't had any issues with old heads either, but your note intrigues me.
If the suspension sagged, I would expect reading the TOC would be an issue, or even initial focus lock. If the suspension was getting hard, that would cause the behavior you just described. Either way, a very interesting report.
Wow, I didn't see that notice. The KSS-240A is basically a KSS-210A with the RF amp mounted on the head. I haven't had any issues with old heads either, but your note intrigues me.
If the suspension sagged, I would expect reading the TOC would be an issue, or even initial focus lock. If the suspension was getting hard, that would cause the behavior you just described. Either way, a very interesting report.
Its a very long time ago Chris but I do remember it. The other very early bulletin bulletin when CD was all new was the one that cautioned against using iso for lens cleaning on early pickups with coated optics as it could strip the coating and cause damage.
And I think there was even one over cloudy lenses from pickups in storage in humid conditions. Seem to recall that wasn't an issue and they regained clarity once in service and presumably warm and dry.
And I think there was even one over cloudy lenses from pickups in storage in humid conditions. Seem to recall that wasn't an issue and they regained clarity once in service and presumably warm and dry.
I have some ideas (not tested yet) for evaluating focus/tracking actuator performance.
To me it seems that modern generic KSS-240A pickups track better than any original Sony KSS-240A which I’ve compared with.
But I cannot say for sure that aging deterioration of the plastic focus/tracking actuator support hinges is the root cause.
Things I have observed:
The original Sony KSS-240A has the RF amplifier and the laser APC op-amp embedded inside the same clear epoxy IC which also contains the ABCD EF photo detector diodes. I have seen cases where this clear epoxy IC failed or became intermittent.
The currently available generic KSS-240A pickup has a separate standard black epoxy SOIC IC containing the RF amplifiers & APC amplifier mounted on its PC board. It’s clear photodetector IC contains only the ABCD EF detector diodes. That’s why it has fewer pins. I believe the same photodetector IC is used in modern generic KSS-210A, KSS-213A, & KSS-240A.
It is possible that today’s manufacturers make one opto-mechanical section which can work for the KSS-210A, KSS-213A, & KSS-240A, with each of these having a different PC board.
So far I have been very happy with the performance of 10+ units of modern generic KSS-240A which I’ve installed into a bunch of different CD players within the past 2 months.
I’m just getting started with trying generic KSS-210A and KSS-213A. I had one bad experience where a complete KSS-213A transport assembly from China was so poorly packed that it arrived with:
1) Broken PC board under the sled and spindle motors.
2) Disc platter jammed down against the top of the optical pickup and permanently warped as a result.
3) Plastic sled drive gears damaged.
The seller did give me a full refund of the $14 USD purchase price. And I’ve already used the sled drive motor which was undamaged & works perfectly. I haven’t tried using the optical pickup itself yet. It appears to be undamaged. And it has the solder blob protecting the laser diode.
-EB
The most recent item on my workbench containing a KSS-240A optical pickup is another 5-disc CD changer:
Sony CDP-C305.
My cost: $6 USD. It’s in good shape cosmetically, though rather dusty both inside and out.
It was thoroughly non-functional:
1) The tray would not open. I suspect a previous repair attempt where the transport raising/lowering mechanism wasn’t reassembled properly. Rotation of the “manual tray release” screw underneath failed to open the tray. It was necessary to remove the front panel & the tray retainer bar which then allowed the entire tray to be lifted out Fortunately no pieces were missing or broken. Proper realignment of the cam wheel made it functional again.
2) The optical pickup sled frequently did not return to its “home” position. This was caused by a faulty sled drive motor. This also was a partial cause of fault #1: If the sled fails to reach its “home” position then the MCU won’t apply power to the tray motor. However the tray can still be opened by manually rotating the cam wheel from underneath. Replacement of the sled motor fixed problem #2.
3) At this point a disc can be played but with substantial skipping and extreme sensitivity to external shock & vibration. Dropping a feather on the workbench is sufficient to get it to skip. The RF level is only 800mV P-P. But it is supposed to be 1.2V P-P. Cleaning the lens increased the RF signal to 950mV. But it still skips (just not as frequently). I installed a new “generic” KSS-240A. Bingo! 1.2V P-P RF (spot-on). Now it plays well without skipping. To get it to skip from vibration I must hit my workbench with a rubber mallet.
4) Occasionally the tray still fails to open. The leaf-spring detector switch for sled “home” position has dirty contacts. This switch is supposed to close when the sled reaches the “home” position. I applied a few drops of contact cleaner to the leaf switch. Hopefully this will clear it up.
-EB
Sony CDP-C305.
My cost: $6 USD. It’s in good shape cosmetically, though rather dusty both inside and out.
It was thoroughly non-functional:
1) The tray would not open. I suspect a previous repair attempt where the transport raising/lowering mechanism wasn’t reassembled properly. Rotation of the “manual tray release” screw underneath failed to open the tray. It was necessary to remove the front panel & the tray retainer bar which then allowed the entire tray to be lifted out Fortunately no pieces were missing or broken. Proper realignment of the cam wheel made it functional again.
2) The optical pickup sled frequently did not return to its “home” position. This was caused by a faulty sled drive motor. This also was a partial cause of fault #1: If the sled fails to reach its “home” position then the MCU won’t apply power to the tray motor. However the tray can still be opened by manually rotating the cam wheel from underneath. Replacement of the sled motor fixed problem #2.
3) At this point a disc can be played but with substantial skipping and extreme sensitivity to external shock & vibration. Dropping a feather on the workbench is sufficient to get it to skip. The RF level is only 800mV P-P. But it is supposed to be 1.2V P-P. Cleaning the lens increased the RF signal to 950mV. But it still skips (just not as frequently). I installed a new “generic” KSS-240A. Bingo! 1.2V P-P RF (spot-on). Now it plays well without skipping. To get it to skip from vibration I must hit my workbench with a rubber mallet.
4) Occasionally the tray still fails to open. The leaf-spring detector switch for sled “home” position has dirty contacts. This switch is supposed to close when the sled reaches the “home” position. I applied a few drops of contact cleaner to the leaf switch. Hopefully this will clear it up.
-EB
A new generic KSS-240A and a new sled motor made a world of difference for this Sony CDP-C305.
But… It still tended to skip at one spot about halfway through each disc.
Close inspection revealed one deformed gear tooth on the black plastic rack gear attached to the KSS-240A. I’m pretty sure I damaged it myself (accidentally). The damage really “hung up” the sled at that one tooth. Everywhere else the sled moved freely and smoothly.
In retrospect I’m surprised it didn’t stop dead in its tracks when it hit that damaged tooth. A bit of whittling and reshaping with a magnifying glass and a sharp knife got it all moving freely again.
I’m also ordering a tube of that super-duper special plastic grease. I’m thinking that proper sled lubrication is good for every vintage CD player. Most of the grease in this CDP-C305 is dry and crumbly. This machine was probably stored away in a garage or attic for 20+ years.
-EB
What if one side of these plastic actuator/lens suspension hinges warps or gets more/less flexible than the other side?
The main purpose of the actuator suspension is to keep the lens optically aligned. If the lens tilts to one side as it moves that will misalign the light beam.
The actuator/lens assemblies in Sony DVD pickups use thin spring-steel wires instead of plastic hinges. I've also seen early optical pickups (TAOHS for example) with robust spring-steel strips holding the actuator/lens mechanism. I expect spring steel is likely to maintain proper optical alignment longer than flexible plastic.
I continue to be impressed by the performance of today's low-cost "generic" KSS-240A optical pickups. Every one I've tried seems to work considerably better than any original vintage Sony KSS-240A which I've encountered so far.
Although I do have a several old vintage KSS-240A pickups which can still play discs with adequate RF signal output (>1V is my benchmark), most of them are much more "vibration sensitive" than the new pickups. Over time I may learn why. Possibilities:
- New generic pickups have actuators with lower moving mass
- "Fresh" plastic hinges maintain better optical alignment than ones that are 25+ years of age
- The new pickups have stronger actuator magnets. This corresponds to having higher servo gain.
-EB
-EB
Hi deadpool,
I generally change both head and spindle motor.
Where units are used in random mode, you are quite right. The motors are usually the problem. If used to play the entire CD, motors can last longer than the head. A restaurant can kill a CD player in 90 days flat. Sometimes in less time. Over here many distributors either cancelled warranty, or only warrantied CD players for 90 days if used commercially in response to high warranty claims. They reacted pretty quickly.
-Chris
I generally change both head and spindle motor.
Where units are used in random mode, you are quite right. The motors are usually the problem. If used to play the entire CD, motors can last longer than the head. A restaurant can kill a CD player in 90 days flat. Sometimes in less time. Over here many distributors either cancelled warranty, or only warrantied CD players for 90 days if used commercially in response to high warranty claims. They reacted pretty quickly.
Well, no. Always troubleshoot the unit 1st. You can determine if the motor is toast often by watching the eye pattern. Same for the head. For high mileage units, replace both.
-Chris