Hi, I use Philips "SBC 444A PLAYABILITY" test C.D. it's quite good for checking servo operation with various disc defects. If I could figure out how to get images to attach to a message I could post a pic of disc. Anyone ? I click "browse" and find image O.K. but it never shows in message or preview.
Regards Karl
Regards Karl
Hi Karl,
Your disc is probably fine for adjusting the disc. So go ahead and use it. Defect discs are required as well. Pierre Verany was excellent.
Hi Salar,
I use a Dremel to cut the shaft. I power the motor through a resistor to make it spin (not too fast) and hold the Dremel running in one spot. This makes very nice, even cuts. Left the motor running and face the shaft, the make a rounded bevel on the tip. This works very well and doesn't take that long to do once you figure it out. Sometimes I have made them that look identicle to the commercial motors the correct length. More often than not, it's acceptable but not perfect. That is fine. The only thing to watch is that you take your time so the motor bearing is not overheated.
-Chris
Your disc is probably fine for adjusting the disc. So go ahead and use it. Defect discs are required as well. Pierre Verany was excellent.
Hi Salar,
I use a Dremel to cut the shaft. I power the motor through a resistor to make it spin (not too fast) and hold the Dremel running in one spot. This makes very nice, even cuts. Left the motor running and face the shaft, the make a rounded bevel on the tip. This works very well and doesn't take that long to do once you figure it out. Sometimes I have made them that look identicle to the commercial motors the correct length. More often than not, it's acceptable but not perfect. That is fine. The only thing to watch is that you take your time so the motor bearing is not overheated.
-Chris
Hi Chris,
the Vernay disc only seem to be available used at a hefty price premium (US$75+).
I while searching around, came across these discs...
http://www.mcminone.com/product.asp?catalog_name=MCMProducts&product_id=32-17450
http://www.mcminone.com/product.asp?catalog_name=MCMProducts&product_id=80-5620
looks like a pretty reputable maker... any thoughts on these?
could pick up both for the cost of a used PV set.
cheers
Paul
the Vernay disc only seem to be available used at a hefty price premium (US$75+).
I while searching around, came across these discs...
http://www.mcminone.com/product.asp?catalog_name=MCMProducts&product_id=32-17450
http://www.mcminone.com/product.asp?catalog_name=MCMProducts&product_id=80-5620
looks like a pretty reputable maker... any thoughts on these?
could pick up both for the cost of a used PV set.
cheers
Paul
Hi Paul,
This one "32-17450" looks to be the one you might want. This might be the closest thing to Pierre Verany. You do not need a pile of audio test tones. One 0 dB track at 500 Hz or so is all the audio you would need. The other disc might be useful if you had to check EQ to to if the de-emphasis circuit switched in and out properly. Never needed that part.
Keep in mind that Pierre Verany is a two disc set. One with a variety of tones, sweeps and music. The other disc is a constant tone with a large variety of defects recorded. This even includes decreasing HF level and many others. I think it's worth it.
Where did you see P.V.?
-Chris
This one "32-17450" looks to be the one you might want. This might be the closest thing to Pierre Verany. You do not need a pile of audio test tones. One 0 dB track at 500 Hz or so is all the audio you would need. The other disc might be useful if you had to check EQ to to if the de-emphasis circuit switched in and out properly. Never needed that part.
I was paying about $50 USD around 13 years ago for these. My techs destroyed them with regularity. In that light, $75 USD seems to be reasonable these days. Thank goodness I don't have employees anymore!
Keep in mind that Pierre Verany is a two disc set. One with a variety of tones, sweeps and music. The other disc is a constant tone with a large variety of defects recorded. This even includes decreasing HF level and many others. I think it's worth it.
Where did you see P.V.?
-Chris
Hi Chris
I'll post when I get hold of the disc. might be a few weeks down the track.
I'm also wondering what quality of sine wave generator I would need to do the setup procedure described in the T1 manual extract I attached a few posts back? Is a function generator which specs 2% distortion any use or do I need to get hold of a decent low distortion audio generator?
cheers
Paul
I'll post when I get hold of the disc. might be a few weeks down the track.
I'm also wondering what quality of sine wave generator I would need to do the setup procedure described in the T1 manual extract I attached a few posts back? Is a function generator which specs 2% distortion any use or do I need to get hold of a decent low distortion audio generator?
cheers
Paul
Hi Paul,
I'm pretty sure a function generator will work. I always used the oscillator I had on the bench (Leader LAG-120B) for that. These days I have better and would use them. It would have been wonderful to have the HP 3336B or 3324A I currently use. Just type in the frequency and amplitude. It was a pain "dialing in" the generator. You may find some function generators a bit sensitive to use. As an alternative, a program running your sound card might be exactly what you need. It's possible you might need a small buffer amp with some gain with the sound card.
-Chris
I'm pretty sure a function generator will work. I always used the oscillator I had on the bench (Leader LAG-120B) for that. These days I have better and would use them. It would have been wonderful to have the HP 3336B or 3324A I currently use. Just type in the frequency and amplitude. It was a pain "dialing in" the generator. You may find some function generators a bit sensitive to use. As an alternative, a program running your sound card might be exactly what you need. It's possible you might need a small buffer amp with some gain with the sound card.
-Chris
Looks like I found a motor for my Nak with the correct shaft lenght.
I already got my tracking gain adjustment into ballpark I guess - but because I´ll have to open the Nak anyway, I am curious:
I would need a 1khz, 300 mV Audio signal with an output impedance of 220 ohms to adjust tracking gain.
How could I achieve this with my Esi Juli@soundcard, which has the line level of max. - I guess - and needs an impedance of 100 ohms minimum?
The standard procedure is attached - not as well described as manufacturers like Revox or Teac did...
All the best,
Salar
I already got my tracking gain adjustment into ballpark I guess - but because I´ll have to open the Nak anyway, I am curious:
I would need a 1khz, 300 mV Audio signal with an output impedance of 220 ohms to adjust tracking gain.
How could I achieve this with my Esi Juli@soundcard, which has the line level of max. - I guess - and needs an impedance of 100 ohms minimum?
The standard procedure is attached - not as well described as manufacturers like Revox or Teac did...
All the best,
Salar
Hi Salar,
The impedance in the first case is supposed to be 220 K ohms. I used a 220 K ohm resistor in series with my oscillator. This is quite common actually, most test jigs insert resistance in series with the oscillator. This is so you can inject a signal without loading down the normal signal of the circuit.
-Chris
The impedance in the first case is supposed to be 220 K ohms. I used a 220 K ohm resistor in series with my oscillator. This is quite common actually, most test jigs insert resistance in series with the oscillator. This is so you can inject a signal without loading down the normal signal of the circuit.
-Chris
Close up of the PHILIPS SBC444A Playability Disc. The dark rectangle isn't clear in picture but is a "simulated finger print" and is a grid of fine horizontal lines. The light wedge is "interuption in information layer. and consists of 7 tracks ranging from 400 to 1000 micrometer in size. Black dots are 300,500,600,800 micrometer in size. Any player should be able to play the 400m/m interuption, the 300m/m dot and the simulated finger print. My Micromega with a CDM12.4/05 will play all with no audible errors, but you can hear the servo working overtime on the more severe tests. So here it is, and a big thanks to Anatech who helped to get it here.
Regards Karl
Regards Karl
Attachments
Hi Karl,
That disc then replaces Philips 5A. They copied PV's idea as they used to simply print the defects on top of the CD in ink. That looks like a good test disc.
How much was it and where did you get it? It would be nice to have some options. My test discs are very old now (but still good).
Hey Paul,
Sorry, I forgot to answer your question.
-Chris
That disc then replaces Philips 5A. They copied PV's idea as they used to simply print the defects on top of the CD in ink. That looks like a good test disc.
How much was it and where did you get it? It would be nice to have some options. My test discs are very old now (but still good).
Hey Paul,
Sorry, I forgot to answer your question.
Yes, that should be fine.
-Chris
Hi Chris, I have had the discs about 12 years, they were from a local spares wholesaler, forget how much now but £80 ish for the two disc set seems to ring a bell. Google SBC444A and it throws up more than you might think. Also look here www.opticalstorage.philips.com/about/products/testdiscs/catalogue/section-13824/710409924991.html
Regards Karl
Regards Karl
Hi Karl,
That is exactly the defects used on 5A. The original 5A disc cost me $250 CDN, disc #5 was $200 CDN. I had no choice back then.
Your 150 pounds sounds about right. They haven't changed at all.
Thank you for posting that information.
-Chris
Edit: Here are all teh test discs Philips offers : "Click here for Philips test CDs"
I see they still make the glass adjustment CD's available.
That is exactly the defects used on 5A. The original 5A disc cost me $250 CDN, disc #5 was $200 CDN. I had no choice back then.
Your 150 pounds sounds about right. They haven't changed at all.Thank you for posting that information.
-Chris
Edit: Here are all teh test discs Philips offers : "Click here for Philips test CDs"
I see they still make the glass adjustment CD's available.
