Recommendation / explanation request

[WindEng]

Hi Gang,

I am looking for a recommendation and an explanation if you are willing to provide. If you dealt with this, what would you do? I am willing to pay money for a new device, but I don't want to spend more than a handful of hundreds of dollars.

I have an ADCOM GCD 700 carousel player from sometime in the 90s and I'm acquiring newer CDs that it will read some of the time but not all the time and sometimes it will just produce crummy sound resembling a song with weird cyclic resonance (e.g. levels up and down, perhaps at disk RPM, I really don't know more). I am not a super-technical audiophile but I need an answer as I am going a little nuts with this, more-so now cooped up with COVID19. I acknowledge that a newer player will probably handle "improvements" in CD manufacturing technology - for instance - my 2015 Honda radio does not have the issues my older and more expensive ADCOM has. But is THIS my problem? Or do I have something more serious going on with the old reliable (to me - note that I did not refer to a quiet transport!) ADCOM? Please don't waste time with the format item many run into. I think I understand that one (not in MP3 land here).

Thank you!

Kirk
(WindEng)

PS I saw the CD player recommendations and it looked like it needed and update. Is there a way to cross-post?

 

[JoeESP9]

Laser pickup assemblies have a finite lifespan. After 20+ years many from that era are dying.

If you're not married to a carousel type player buy a new CD player. There are numerous ones available at every price point.

Some will recommend their favorite vintage player. Unfortunately, they may have the same age related problems you're currently experiencing.

 

[Music2Myear]

Maybe a laser lens cleaning and rail lubrication??

 

[WindEng]

What baffles me is that the new CDs I have on hand will get some trouble, but I can put in some old CD I get at half-price or have in my collection (like the ones, with no obvious defects) and there is NOOOOO problem. Am I wrong to suspect a change in the manner of disc production that is causing my problems? I recall reading someplace that the bits on the surface of disc can be achieved in a couple different methods. Are the older laser assemblies poorly suited to the newer method of making the bit dots or something? Any super-geeks out there?

WindEng
ADCOM GTP 450, GCD 700, GFA 555, McIntosh LS310, PS112, Audioengine B1 (awesome little unit I can recommend)

 

[Music2Myear]

Have you cleaned the laser lens?

 

[northpaw]

...new CDs I have on hand will get some trouble, but I can put in some old CD I get at half-price or have in my collection (like the ones, with no obvious defects) and there is NOOOOO problem

If it really is CD-dependent, then you should be able to rule out needing rail lubrication and needing spindle motor lubrication (two of the more common ailments), but not a dirty lens. So you should try to gently clean that, and see if you get improvement.

I have read that the reflectivity of newer CDs can be less than older ones. Not much you can do about that, but it is likely that if the lens is dirty, it is likely reducing the ability to read a less reflective CD than a more reflective one.

In the meantime, if you have a DVD player in the house, you can sub it in your system until you sort out the Adcom.

 

[WindEng]

Northpaw I appreciate your note and the interim solution you proposed and I think the reflectivity item is interesting, especially with how you applied it to the potential instance of a dirty lens. I ordered a used Onkyo C-7030 to swap-in for the ADCOM. I'll remove the ADCOM case cover and clean what I can, including the lens and see how it runs then and report back before going after the rails, spindle, etc. Thanks all.

 

[WindEng]

Update 4/2/2020 - I got the ADCOM GCD 700 case off and could see lots of fibers around the lens assembly. To baseline testing I ran my test disk and produced the chatter sounds and I produced the seek (track-skip hunt) issue. I then went to lens cleaning. The configuration is such that I cannot get directly overhead of the outer lens (let alone an inner lens if there is one). Despite this, reaching in from the side of the assembly, I cleaned the lens with a silicone-tipped swab and 91% isopropyl alcohol then swabbed with a bit of paper tower and then swabbed with just the silicone tip and alcohol one last time and let it dry. Around this time I also blew in canned compressed air (believed to be clean and oil free as from a can) to disperse all the fibers I could see. I put the test disk back in. No chatter at first. The seek issue seemed OK for adjacent tracks (1 to 2 and 2 to 3) but I went from track 1 to track 14 and the player appeared to get into a loop hunting for track 14. Previously it would bail out entirely though so there would appear to be some improvement. I tried the older disc (one that has never displayed problems). Still not problems with this one. I can skip around, it plays fine all the time. I went back to the newer test disk. I can get the chatter on the first track and then it seems to dissipate. I tried the disc that gave the unusual cyclic sounds and chatter. I can still get that but it's not as frequent. Overall, it seems like my issues were helped by what I did with the lens, but it's not exactly solved. For more comparison, the new (used) Onkyo C-7030 handled the test disks just fine for the most part. But I can hear some chatter with the second of the two disks. The Onkyo was manufactured 2013.

Northpaw I am tending to believe that this is the reflectivity issue manifest, but I don't know for certain.

Not sure if others have seen this, so I thought I would share it - a really detailed troubleshooting page for laser disk players. I did not have the patience to read all of it through. But there is mention of changing disk manufacture technology and associated problems. https://www.repairfaq.org/sam/cdfaq.htm

I will see what Google and an ADCOM tech can tell me.

 

[northpaw]

lots of fibers around the lens assembly

That isn't normal. Are there fibers elsewhere as well? I'd wonder how they got in there. Could they be pet hairs?

I'd be careful to clean the entire inside of the unit of fibers, dust, etc., or they can recontaminate the lens and other things, such as the lubricated parts. Blowing out the chassis with canned air is one way; vacuuming is another (only consider using a HEPA-filtered unit and keep the power unit as far away as possible or you may generate more dust than you get rid of). Then re-clean the lens.

One thing to watch out for is generating static, as it will tend to make the fibers/dust stick to things. Rubbing things generates static, and a dry atmosphere makes it harder for the static to dissipate. So keep motions slow and on the spare side. I'd avoid paper products (generates too much dust). For lens cleaning, I've preferred cotton Q-tips ever-so-slightly moistened with ethanol or distilled water (see dr*audio's Troubleshooting CD Players sticky post at the top of the DIY section) and use a very gentle hand. I would wonder if a silicone tip would have much ability to hold any dust it comes into contact with.

Anyway, it seems you are making progress. Good luck.

 

[cpt_paranoia]

Track density has increased marginally over the original disks. Hence the increase in capacity from 650MB to 700MB, and playing time to just under 80 minutes.

An older player may have more trouble with the higher density.

Not saying this is definitely the cause, but it's a possibility.