Hi all,
I agree with Guido, the biggest issue in the drive mechanisme is jitter. Then you should reduce the jitter to minimum effect. Of course there are some reasons to consider about clamping and demagnetizing the CD, but still the source of jitter will be the primary enemy to be the best drive mechanism.
Boy
I agree with Guido, the biggest issue in the drive mechanisme is jitter. Then you should reduce the jitter to minimum effect. Of course there are some reasons to consider about clamping and demagnetizing the CD, but still the source of jitter will be the primary enemy to be the best drive mechanism.
Boy
Hi Bernhard,
Well, the lower the rotating mass is, the more accurately your disc motor can correct for velocity changes when required. Think eccentric disc. This is all within reason and as long as nothing else becomes compromised.
Hi QSerraTico_Tico,
Ahhhh, no.
Don't worry about any of this. The reflective layer is normally aluminum.
Now you can sleep at night!
-Chris
Well, the lower the rotating mass is, the more accurately your disc motor can correct for velocity changes when required. Think eccentric disc. This is all within reason and as long as nothing else becomes compromised.
Well, let's just say that no clearly audible things happen. Watch your C1, C2 flags when you try that next time.
Hi QSerraTico_Tico,
Ahhhh, no.
Don't worry about any of this. The reflective layer is normally aluminum.
Now you can sleep at night!
-Chris
maxlorenz said:
I did some listening tests today on my CD-Pro2 with magnetic clamp and with Sony sourced brass clamp. The latter certainly sounds better to the point that I will not go back to magnetic one: there is more air and dimentionality, while with magnetic clamp the sound is rather "gray" and less involving.
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The way the magnetic clamp works on CD Pro is not optimal either. The magnet does not "stick" to the turntable, but to the steel plate attached to the die cast frame. That creates unevenly distributed forces that affect motor bearings and the way the motor works; the motor mechanism is under costant stress, possibly bigger than from a heavier non magnetic clamp.
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Hi Peter,
What is the table made from? Are you sure it isn't metal, or has a metal ring underneath?
Every transport I have ever seen with a magnetic clamp has a metal turntable, or a metal ring under a plastic table if they are super cheap. A metal table ensures that the CD runs true.
-Chris
What is the table made from? Are you sure it isn't metal, or has a metal ring underneath?
Every transport I have ever seen with a magnetic clamp has a metal turntable, or a metal ring under a plastic table if they are super cheap. A metal table ensures that the CD runs true.
-Chris
CD-Pro table is made from aluminum. I came across the magnet thing accidently, when I was swapping mechanisms in ML31.5 and the tables needed to be replaced due to different openings in the clamps.
http://www.diyaudio.com/forums/showthread.php?postid=751296#post751296
I also tried to compare the rotating mass of a disc with the Sony clamp and with the magnetic clamp (by turning CD with my fingers). The feeling is basically the same and it's hard to detect any substantial differences.
http://www.diyaudio.com/forums/showthread.php?postid=751296#post751296
I also tried to compare the rotating mass of a disc with the Sony clamp and with the magnetic clamp (by turning CD with my fingers). The feeling is basically the same and it's hard to detect any substantial differences.
Hi Peter Daniel,
I am glad that my comment produced an enhancement in your musical enjoyment
A humble salary for the inspiration we obtained from your famous CDpro thread
Just for curiosity, how long took it to recognize sonic differences between clamps?
Well, months ago I did the above mentioned comparison and I decided not to listen to it until it used a proper non magnetic clamp. Adapting a portable CD's mechanism was not possible without risk of dammaging the center hub so I planned to build my own. Because of the lack of resources and competent technicians here, I ended with a primitive yet trusty, Al based, lightweight mechanism whose photo I could show if ever my little daughter lends me her camera It was made on a big industrial machine tool so it is not perfect. Maybe you who have better tools can make a better mechanism...and probably sell? 
I'm not saying CD-pro2M is the best transport but it's one of the few ready available for ethernal beginners like me to play with
It sounds quite good anyway.
Regards,
M
I am glad that my comment produced an enhancement in your musical enjoyment
A humble salary for the inspiration we obtained from your famous CDpro thread
Just for curiosity, how long took it to recognize sonic differences between clamps?
Well, months ago I did the above mentioned comparison and I decided not to listen to it until it used a proper non magnetic clamp. Adapting a portable CD's mechanism was not possible without risk of dammaging the center hub so I planned to build my own. Because of the lack of resources and competent technicians here, I ended with a primitive yet trusty, Al based, lightweight mechanism whose photo I could show if ever my little daughter lends me her camera
It was made on a big industrial machine tool so it is not perfect. Maybe you who have better tools can make a better mechanism...and probably sell? I'm not saying CD-pro2M is the best transport but it's one of the few ready available for ethernal beginners like me to play with
It sounds quite good anyway.
Regards,
M
maxlorenz said:I'm not saying CD-pro2M is the best transport but it's one of the few ready available for ethernal beginners like me to play with
It sounds quite good anyway.
CD-Pro is not bad at all but needs proper implementation; especially power supply and mechanical installation.
I'm checking now various caps in filtering and it looks like BG FK work really good (better than STD and N), next I will try different regulators.
Hi Peter,
Do you ever monitor the error flags when you do these modifications? This is one place where this number should correlate to listening. If it doesn't, I'm going with the error rate numbers (minimum). That indicates the lowest digital error. It would also tell me that something else is going on to investigate.
CD reproduction is one area where the error rate ought to be set to it's lowest value for the best sound. It is not possible to get better sound with more errors. All the work that Guido Tent and others have done has been to reduce digital errors in various points in the chain.
-Chris
That does not surprise me at all. The inertial mass of the CD should be much higher than the clamp. Your fingers are not accurate enough to determine any difference in the moment required to spin the CD.
Do you ever monitor the error flags when you do these modifications? This is one place where this number should correlate to listening. If it doesn't, I'm going with the error rate numbers (minimum). That indicates the lowest digital error. It would also tell me that something else is going on to investigate.
CD reproduction is one area where the error rate ought to be set to it's lowest value for the best sound. It is not possible to get better sound with more errors. All the work that Guido Tent and others have done has been to reduce digital errors in various points in the chain.
-Chris
QSerraTico_Tico said:
The advantages of good clocks are vastly exaggerated.
At least once I removed myself the good clock and installed back the regular crystal because it did sound better.
It seems like I wasn't the only one:
http://www.goodsoundclub.com/GetPost.aspx?PostID=2128
anatech said:
I do not, but I will agree that amount of errors may indicate the accuracy of CD readout, however, it may not neccessarily indicate subjective sound quality. If it did, we would need to assume that all cables sound the same and PS capacitors do not make a difference, which is not exactly what I've experienced so far.
I also suspect that modifications I'm performing do not affect the amount of error rate.
Hi QSerraTico_Tico,
More like " -All differences between clocks vanish to zero with a bad transport.". At least this statement is true.
Understand this. Your data starts as the RF signal coming off the transport. You can lock a clock to garbage data, but nothing will make garbage into something useful. So you must start with a good transport. From there all you can possibly do is to damage the data and create errors. That you do with a poor clock and other evils. All parts of the system are important.
So, who gave you that incorrect knowledge?
-Chris
Why would you say that? You are dead wrong!
More like " -All differences between clocks vanish to zero with a bad transport.". At least this statement is true.
Understand this. Your data starts as the RF signal coming off the transport. You can lock a clock to garbage data, but nothing will make garbage into something useful. So you must start with a good transport. From there all you can possibly do is to damage the data and create errors. That you do with a poor clock and other evils. All parts of the system are important.
So, who gave you that incorrect knowledge?
-Chris
Hi Peter,
Damaged data is bad sound. The subjective effect of that depends on the error correction and other possible mistakes in the system. After all, the data should be bit perfect for proper decoding. Anthing else is distortion.
The other things you are saying point to the myriad of other things in a CD playback system that can matter. I think you will agree that we should at least start without errors.
Just think. You could to get into DSP programming. Here you can create whatever distortion sounds good.
Just kidding Peter! You still need to start with good data though.
-Chris
Damaged data is bad sound. The subjective effect of that depends on the error correction and other possible mistakes in the system. After all, the data should be bit perfect for proper decoding. Anthing else is distortion.
The other things you are saying point to the myriad of other things in a CD playback system that can matter. I think you will agree that we should at least start without errors.
Just think. You could to get into DSP programming. Here you can create whatever distortion sounds good.
Just kidding Peter! You still need to start with good data though.-Chris
Looks like everybody here is convinced of something else.
Some are crazy about clocks, others about RF signals.
My experience is that even very scratched CDRs still sound very good until dropouts occur.
And those same CDs sound very different via different DACs and different transports.
I once tried to install one of the forum clocks in a Philips CD with no noticeable change in sound.
Also better supply bypassing did not bring improvement in the Philips.
But it did in Yamaha.
So maybe the chipsets play a role...
I have to try the forum clock in the Yamahe and a bunch of oven clocks also.
Anybody knows how to tune the 10MHz of a rubidium clock to another frequency ?
Some are crazy about clocks, others about RF signals.
My experience is that even very scratched CDRs still sound very good until dropouts occur.
And those same CDs sound very different via different DACs and different transports.
I once tried to install one of the forum clocks in a Philips CD with no noticeable change in sound.
Also better supply bypassing did not bring improvement in the Philips.
But it did in Yamaha.
So maybe the chipsets play a role...
I have to try the forum clock in the Yamahe and a bunch of oven clocks also.
Anybody knows how to tune the 10MHz of a rubidium clock to another frequency ?
Hi Bernhard,
Many things matter. I'm not crazy about RF signals, this is only the beginning. I've had to troubleshoot and repair all kinds of problems in CD players over the years. The distortion complaints can sometimes be the hardest to find. The early CD players sometimes had a "stuck bit" due to IC defects or soldering.
My message is very simple. If you want good sound, everything matters. That should sound familiar as it applies to the entire sound system as well.
-Chris
Many things matter. I'm not crazy about RF signals, this is only the beginning. I've had to troubleshoot and repair all kinds of problems in CD players over the years. The distortion complaints can sometimes be the hardest to find. The early CD players sometimes had a "stuck bit" due to IC defects or soldering.
My message is very simple. If you want good sound, everything matters. That should sound familiar as it applies to the entire sound system as well.
-Chris