QuestionQUESTION: Hello, I have several old cd players and a couple of hundred compact discs of
varying quality. A while ago some of my discs got scratched due to a
malfunctioning drive. When i played these discs on any give player again I heard
a repetitive tick-tick sound. On listening closer to some other discs I could
also hear it. I could ignore it and treating the discs with the worst noise does
help somewhat but the problem still bothers me. When I came to think about it I
had heard other players make slight noises in the past as well. So my question
is this;
Why do CD players make this sound, and what can be done if anything to
effectively remove it from a given player?
I think the Compact Disc is still a great invention, but they must have
considered this during its development. I have never heard this on vinyl and
these sounds are almost as annoying as actual gaps in the audio! There may have
been development in error-correction technology that I am unaware of and I would
be grateful if you would inform me, if you can offer no immediate practical
advice. I have been thinking about this for some months and am really at my
wit's end, and if you could take some time out to consider, and if necessary
investigate this problem I cannot say I would be eternally grateful, but I would
be very so.
ANSWER: Can you explain to me more exactly what the noise is you are hearing. Answer these questions?
- Is it coming from inside the player mechanism or out of the speakers?
- What players are you referring to specifically? Make and model and age?
- Is it present with all/any disc?
- Does it remain constant over time? Or is it just during start up and TOC reading?
- You talk about damage to the discs. Are these the only ones that have the noise? Does the noise synchronize with scratched surfaces on the disc?
From your question I cannot tell if you are having a problem with error correction, with damaged discs, with mechanical and motor noises or a problem in your playback components (preamp, amp or receiver).
Await your further clarification.
Cheers.
PS: If you have damaged the discs and if the damaged area causes a drop out of digital data which is greater then the error detection and correction system can accommodate then you will hear a tick or drop out or muting result. There are surface treatments that can be applied to discs that will improve the resulting error from these surface defects but may not correct them completely. Since the data recorded on the disc is extremely small (like light waves) a visible sratch mark on the surface will block out thousands, maybe millions of data bits when read back by the laser system. You may be experiencing discs that are damaged beyond the ability of a player to handle. If new, unscratched discs are playing correctly then this is likely what you are experiencing.
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QUESTION: Thank you for your quick response, Here I go.
The problem I am referring to is the mechanical motor noise of error-correction and if there are solutions.
First off, I have never had a CD player skip audio (except once when I hadn't set it up right). What I want to know is the logic of CD error-correction and if this noise can be muted or if there is a system without it. I can't understand why this wouldn't have been considered during the invention of the CD as music listening is an inherently aural experience and the error-correction can cope with it seemingly. Would the possibility of skips make a player make less noise? I would be willing to risk it. My Cd players are Micro setups (decent ones though not cheap tacky ones) not a whole amplifier type setup (although would that help?).
What I think you can tell me is the logic behind the motor noise and about error-correction technology and potential personal solutions, which I would like. Thank you.
ANSWER: I don't understand what you are talking about. Error detection and correction is done in software and has little to do with motor noise.
Perhaps you are confused about what goes on in the cd player. It is a constant velocity system and hence the motor does not run on a constant angular basis. It changes speed according to the data transfer rate and hence the speed is adjusting until the buffer is filled; then it goes again. If you are hearing excessive run noise from the motor and spindle then either the design is a poor design or there is a defect somewhere.
For a give player if the seeking noise is annoying you can acoustically isolate or enclose it in a silent box or something like that.
The reason I need your make and model number is so I can study the electro mechanical and acoustic design. You may be using low cost, budget class player drives that are just plain noise due to keeping the cost down at the manufacturer end. If you are of "golden ears" and bothered by minute sounds then you should be stepping up to higher grade merchandise.
Does this help?
---------- FOLLOW-UP ----------
QUESTION: Okay so would I need a CD player, amplifier and speakers? Thank you.
AnswerThanks. What is the make and model of any of the cd players you are hearing the pulse noise and under what conditions? (Amplifier and speaker arrangement?)
I am still not certain what your problem is or if there is a problem. Can you clarify?
Domo
