Hi all
My CD/DVD player is Denon DVD-2800. The player produces good quality of sound and works fine for me in general. But, sometimes the player makes me frown and nervous. It vibrates, and even I see it. It does when not all but certain CDs are inserted into the tray and played on. The vibration comes as if due to unbalanced rotational vector forces. It seems however that the vibration does not disorder the musical notes. Nevertheless, I absolutely dislike this kind of vibration, and want to kill it into quietness. I really want to solve the problem. But, the serious obstruction to me is that I have no idea about the CD transport mechanism.
Did any of you have the similar experience? How did you solve it? Could you kindly guide me? Thanks.
JH
My CD/DVD player is Denon DVD-2800. The player produces good quality of sound and works fine for me in general. But, sometimes the player makes me frown and nervous. It vibrates, and even I see it. It does when not all but certain CDs are inserted into the tray and played on. The vibration comes as if due to unbalanced rotational vector forces. It seems however that the vibration does not disorder the musical notes. Nevertheless, I absolutely dislike this kind of vibration, and want to kill it into quietness. I really want to solve the problem. But, the serious obstruction to me is that I have no idea about the CD transport mechanism.
Did any of you have the similar experience? How did you solve it? Could you kindly guide me? Thanks.
JH
With certain CDs, when there are vibrations in the CD transport, the vibration level is high at track no.1, and reduced at track no.2, and further reduced at track no.3, and quiet from the track no.4 to the end.
Is this additional info helpful for your advice?
JH
Is this additional info helpful for your advice?
JH
As a thought and I don't know for sure but I think it is like this (at least I think so).
1.
CDs are not always prefectly centered (esp software CDs). Simple enough...
2.
The CDP starts playing the CD from the center and as the circumference is smallest there the speed will be highest and when the CD reads further out on the CD the speed drops as circumference is larger and thus fewer revs are needed for the same amount of data. The higher the speed the more noticable the vibrations of course.
This is why the vibrations disappear at the end of the CD.
/UrSv
My advice is the same as for copy protected CDs. Bring them back to the shop and demand a new working copy.
1.
CDs are not always prefectly centered (esp software CDs). Simple enough...
2.
The CDP starts playing the CD from the center and as the circumference is smallest there the speed will be highest and when the CD reads further out on the CD the speed drops as circumference is larger and thus fewer revs are needed for the same amount of data. The higher the speed the more noticable the vibrations of course.
This is why the vibrations disappear at the end of the CD.
/UrSv
My advice is the same as for copy protected CDs. Bring them back to the shop and demand a new working copy.
I have experienced the same thing with some of my CDs. My CD of Bel Canto - Rush is especially bad. It's because the CD is out of balance. In the case of Rush the decor on the top of the CD is very uneven, on side has a thick layer of dark color while the other side has a thin layer of a light color.
My solution is to burn a copy of the CD in my CD-R and play the copy instead. I keep the copy in the same cover as the original.
Tor Arne
BTW! Damn I hate copy-protected CDs!!!!!!!! 😡
My solution is to burn a copy of the CD in my CD-R and play the copy instead. I keep the copy in the same cover as the original.
Tor Arne
BTW! Damn I hate copy-protected CDs!!!!!!!! 😡
Thank you for your advices, UrSv and Tor Arne.
I agree that the vibration of the transport is due to the rotating unbalance, which is common source of vibration excitation. It seems that my case is due to the high frequency resonance when the CDs having eccentric masses are rotating at high speed. This might mean that the transport is made with weak mechanical supports of flexible spring stiffness. If so, this must be a poor engineering.
If I use the problem CDs with other players, I do not have the same CD transport vibration.
If possible, I want to find a method how to reinforce the spring stiffness of the support system of the transport. By doing so, I could have increased natural frequency of the transport, which is far above the excitation frequency caused by the rotating unbalance.
I would like to remove this kind of undesirable resonance problem.
Is there any advice on the method reinforcing the stiffness?
JH
I agree that the vibration of the transport is due to the rotating unbalance, which is common source of vibration excitation. It seems that my case is due to the high frequency resonance when the CDs having eccentric masses are rotating at high speed. This might mean that the transport is made with weak mechanical supports of flexible spring stiffness. If so, this must be a poor engineering.
If I use the problem CDs with other players, I do not have the same CD transport vibration.
If possible, I want to find a method how to reinforce the spring stiffness of the support system of the transport. By doing so, I could have increased natural frequency of the transport, which is far above the excitation frequency caused by the rotating unbalance.
I would like to remove this kind of undesirable resonance problem.
Is there any advice on the method reinforcing the stiffness?
JH
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