I believe your missing the point of a “Test CD” for Alignment of CD mechanisms. It’s not so much the data that’s recorded (unless you need the test tones), but rather the quality of the Disc itself, RF level, Jitter, Disk Wobble and Flatness (warps). There’s no way a CDR copy is going to meet any of these requirements.
If you need it JUST for the test tones, then this is a different matter – however looking at the disc index – I don’t see any special test tones that could not be generated by cool edit etc.
John
If you need it JUST for the test tones, then this is a different matter – however looking at the disc index – I don’t see any special test tones that could not be generated by cool edit etc.
John
Hi HJ Nijland,
I purchased almost all the test CD's. After I became more knowledgeable I realized all I need are some CD's with good eye patterns and the "Pierre Verany" test disc from Old Colony Sound. Catalog # PV. 788031/788032. There are some machines (like the original Philips / Revox units) where you do need the Philips 5 and 5A set. That price is up there too.
Like John said, these are not normal CD's at all. You can't copy them, the physical defects introduced are precise.
-Chris
I purchased almost all the test CD's. After I became more knowledgeable I realized all I need are some CD's with good eye patterns and the "Pierre Verany" test disc from Old Colony Sound. Catalog # PV. 788031/788032. There are some machines (like the original Philips / Revox units) where you do need the Philips 5 and 5A set. That price is up there too.
Like John said, these are not normal CD's at all. You can't copy them, the physical defects introduced are precise.
-Chris
Hi John, hi HJ Nijland,
could you lend me an YEDS-18 for some days? Or, tell me from where to get one?
The source I know charges about 120€ for one disc...
What were your experiences? When adjusting your players, did the disc produce signals as expected on the scope, or, did it not differ from a common audio-CD?
Thanks in advance,
all the best, Salar
could you lend me an YEDS-18 for some days? Or, tell me from where to get one?
The source I know charges about 120€ for one disc...
What were your experiences? When adjusting your players, did the disc produce signals as expected on the scope, or, did it not differ from a common audio-CD?
Thanks in advance,
all the best, Salar
Hi Salar,
There are two types of test disc. The first has a guarantied pitch and HF quality (signal strength) with few to no defects. The second type will have manufactured defects such as defective pit shape (and RF level), eccentricity and interruptions in data (simulated scratches of varying severity). Those discs are not possible to copy. The other discs ("standards") may be simulated by using good normal discs. The focus and tracking gain values will be different for a copy or another disc.
I hope that helps. I have many and know the differences between them. They cost me a fortune way back when.
-Chris
There are two types of test disc. The first has a guarantied pitch and HF quality (signal strength) with few to no defects. The second type will have manufactured defects such as defective pit shape (and RF level), eccentricity and interruptions in data (simulated scratches of varying severity). Those discs are not possible to copy. The other discs ("standards") may be simulated by using good normal discs. The focus and tracking gain values will be different for a copy or another disc.
I hope that helps. I have many and know the differences between them. They cost me a fortune way back when.
-Chris
Hi Chris!
As you said, a disc with a good RF pattern will as well help...
But I would like to use the YEDS as stated in the service manual, just to narrow down the possibility of faults I do in measuring.
The disc named in the service manual is "YEDS-18 Type 3 and 4"
The YEDS I found at a german seller is "only" called YEDS-18, so I have no Idea, if there is serveral issues of them.
Of coure it should be one with a garanteed pitch and HF quality
Copying is a no go, I know.
Another possibility for adjustment might the test disc "CD-Check" from Digital Recordings, because the Pierre Verany discs do not seem to be available anymore (But Old Colony Sound has no catalogue online)
The "CD-Check" only costs about 35$, containing defects in 5 levels, from no defects to level 5. I emailed them about the production quality, (pitch and HF quality), and got the following answer:
CD-CHECK is mainly designed for error correction and
tracking purposes. Other parameters of CD-CHECK disc
meet the standards of audio discs. Many companies are
using our product in manufacturing, adjustments and
repairs.
So i guess not good pitch and HF as a main goal?
But I tried a test signal of CD-Check uses, of course only playabe from a CD-ROM:
A 200hz sine with a 20050hz sine mixed at a level of -1dB. (Don´t know the level on CD-Check)
On the Nak, I heard audible clicks, in average about 2-3 in 90 seconds, one almost always audible about 2-3 Seconds after the beginning of the track (skipping to the beginning of the track within this time frame produced no clicks - something caused by the balance between laser motors and lens coils I guess)
My CDP-X5000 plays the tones perfectly. Should also be useful for judging the heads of a DAT-machine.
All the best,
Salar
As you said, a disc with a good RF pattern will as well help...
But I would like to use the YEDS as stated in the service manual, just to narrow down the possibility of faults I do in measuring.
The disc named in the service manual is "YEDS-18 Type 3 and 4"
The YEDS I found at a german seller is "only" called YEDS-18, so I have no Idea, if there is serveral issues of them.
Of coure it should be one with a garanteed pitch and HF quality
Copying is a no go, I know.
Another possibility for adjustment might the test disc "CD-Check" from Digital Recordings, because the Pierre Verany discs do not seem to be available anymore (But Old Colony Sound has no catalogue online)
The "CD-Check" only costs about 35$, containing defects in 5 levels, from no defects to level 5. I emailed them about the production quality, (pitch and HF quality), and got the following answer:
CD-CHECK is mainly designed for error correction and
tracking purposes. Other parameters of CD-CHECK disc
meet the standards of audio discs. Many companies are
using our product in manufacturing, adjustments and
repairs.
So i guess not good pitch and HF as a main goal?
But I tried a test signal of CD-Check uses, of course only playabe from a CD-ROM:
A 200hz sine with a 20050hz sine mixed at a level of -1dB. (Don´t know the level on CD-Check)
On the Nak, I heard audible clicks, in average about 2-3 in 90 seconds, one almost always audible about 2-3 Seconds after the beginning of the track (skipping to the beginning of the track within this time frame produced no clicks - something caused by the balance between laser motors and lens coils I guess)
My CDP-X5000 plays the tones perfectly. Should also be useful for judging the heads of a DAT-machine.
All the best,
Salar
Hi Salar,
What you are after are specific defects in the CD tracks to test and adjust the servos. The PV disca use a 500 Hz tone to allow you to hear the defect's effects. I generally am watching the scope with teh sound a little audible.
So look for a test disc that tests a CD players tracking ability.
-Chris
What you are after are specific defects in the CD tracks to test and adjust the servos. The PV disca use a 500 Hz tone to allow you to hear the defect's effects. I generally am watching the scope with teh sound a little audible.
So look for a test disc that tests a CD players tracking ability.
-Chris
Hi Salar,
Yes, we need those. Then there are specific defects that we use to adjust the servos. Recovery from an error for instance. E-F balance will allow the beam to enter the proper track after going through an area of no data (scratch). So I adjust with a perfect disc and optimize with a defect disc. Customers do notice the difference.
-Chris
Yes, we need those. Then there are specific defects that we use to adjust the servos. Recovery from an error for instance. E-F balance will allow the beam to enter the proper track after going through an area of no data (scratch). So I adjust with a perfect disc and optimize with a defect disc. Customers do notice the difference.
-Chris
Hi DMJ3000
the 2nd track is 1kHz at 0dB (max.Level)
Ananatech, do you remember at which error level the Nak OMS5II/OMS7II show audible clicks?
I have a CD-Check test CD with error markings, as far as I remember, the test tone on this cd is a 400hz sine wave mixed together with a sinewave of about 18-20khz)
With an error of 0.375mm, my Nak already clicks...
Rrrors are printed on in five levels, from 0.375mm to 1.5mm.
All the best, Salar
the 2nd track is 1kHz at 0dB (max.Level)
Ananatech, do you remember at which error level the Nak OMS5II/OMS7II show audible clicks?
I have a CD-Check test CD with error markings, as far as I remember, the test tone on this cd is a 400hz sine wave mixed together with a sinewave of about 18-20khz)
With an error of 0.375mm, my Nak already clicks...
Rrrors are printed on in five levels, from 0.375mm to 1.5mm.
All the best, Salar
Hi Salar,
The type II didn't track as well as the original one. The original would track fine all the way through Pierre Verany except the horrible last double drop out tracks... After setting up the originals, I was disappointed by the II's. They are closer to an OMS-3/4 mechanism than anything. I believe it was the same head as well.
Still, much better than the Sony KSS-210A and KSS-240 types. I'm sorry I can't remember what was normal for them. Do watch for sticky center post for the lens assy. That will cause trouble that is hard to find when troubleshooting.
Also, keep in mind that different heads and servos react to defects totally differently. A single beam radial (Philips) will not react the same way as a single beam linear (NEC design) or a triple beam linear (most machines - Sony). So one will not track where another will and the other way around.
-Chris
The type II didn't track as well as the original one. The original would track fine all the way through Pierre Verany except the horrible last double drop out tracks... After setting up the originals, I was disappointed by the II's. They are closer to an OMS-3/4 mechanism than anything. I believe it was the same head as well.
Still, much better than the Sony KSS-210A and KSS-240 types. I'm sorry I can't remember what was normal for them. Do watch for sticky center post for the lens assy. That will cause trouble that is hard to find when troubleshooting.
Also, keep in mind that different heads and servos react to defects totally differently. A single beam radial (Philips) will not react the same way as a single beam linear (NEC design) or a triple beam linear (most machines - Sony). So one will not track where another will and the other way around.
-Chris