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HizWiz 25th April 2012 01:15 PM

Removing clamper CDM12.1
Hi all,

I'm currently repairing my almost vintage Philips CD730 (internally similar to CD910/911) as the player suffered from skipping while playing a cd. As I suspected the laser unit to be faulty, I ordered and installed a new unit. The original unit was a CDM12.1, the replacement unit is a VAM1202.

I succesfully replaced the units, but still some problems persist. From several discs, the TOC can't be read. Further, the player displays the error codes er08 and er10. I found out that the clamper must be replaced too, as the original CD12.1 clamper is not compatible with the VAM1202 unit. In fact, this should solve the problem: slightly touching the clamper solves the problem of not reading the TOC. After the touch, the TOC is read and the disc can be played without skips or other problems.

I'm about to order a VAM1201/1202 clamper, but I'm left with an important question: how to remove the old clamper and install the new one? I suspect the clamper to be made from one piece of plastic (with a small magnet inside), but how can it be released from its plastic holding mechanism?

Has anybody experience with this? The CDM12.1 laser unit was widespreadly used in many players produced by Philips and Marantz, but was also to be found in players from NAD, Naim and other brands. Although there is much info to be found about replacing the laser unit, I've found nothing about replacing the clamper.

Regards, Geoffrey

Chivvyp 26th April 2012 08:15 AM


I'm not sure if it's possible to replace the whole unit in this way. Most people just replace the actual laser part. You will probably need to remove the laser unit from the vam1202 and refit it in the CDM12.1.



HizWiz 27th April 2012 10:00 AM

Hi Pete,

The original CDM12.1 was defective, so I swapped it with a replacement laser unit. The original CDM12.1 laser units have gone out of production, but according to Philips this unit is replaced by the VAM1202 unit. However, it had turned out that the latter unit is not compatible with the original magnetic clamp that came with the original laser unit.

This clamp consists of a magnet and a plastic ring with two edges around it (U-profile). Normally, when not in use, the clamp is kept at its position by the two edges surrounding a plastic rig from the large transport mechanism of the player. Because of this construction, I simply can;t find out how to remove and install a clamp without damaging its U-profile.

It is hard to explain, I've linked a small picture from the net. The clamp is the lighter grey round thing on top, resting at the middle of the cd.

Does anyone have an idea?

Kind regards,


marcelnl 27th April 2012 10:59 AM

get rid of that clamp and enjoy better SQ, you'll need a propriatary puck (widely available, Tentlabs might be able to help) if your front loader allows such a thing (may be too thick) or use three needle pin head sized specks of blutack on the disc rotor....been using the latter since the early 90ies until I recently retired my Maratz CD player (gone digital)... it hardly ever fails and sounds better.

even better, change the player to a top loader and have easy are modding it already so why not go all the way

poynton 27th April 2012 03:21 PM

Just gently pry the clamp out!

I've done it many times.



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