diyAudio

diyAudio (http://www.diyaudio.com/forums/)
-   Digital Source (http://www.diyaudio.com/forums/digital-source/)
-   -   Sony laser alignment (kss) in Nad cd (http://www.diyaudio.com/forums/digital-source/77734-sony-laser-alignment-kss-nad-cd.html)

delory 14th April 2006 05:55 PM

Sony laser alignment (kss) in Nad cd
 
Hi guys,

just wondering if anyone can help with the alignment of a kss210a in a nad cd player. New laser, just installed, but was skipping slightly, so I adjusted the pot to change the alignment and it helped, and with a bit of trial and error got it to the best position.

However it seems to only work with the pot turned over much further to the right than I've normally seen it, and seems like it's at the limit of where it can read the disk. By this I mean that if I turn it one micron further the disk starts spinning double speed, and one micron less then it skips again. So it's in the perfect position to play the disks without skipping, which it does, but as it's so far over it makes a whistling noise as it plays. If I adjust it back slightly, the whistling stops, but then I get the intermittent skipping again.

Any thoughts? :cool:

Eva 14th April 2006 06:21 PM

I don't know the exact alignment procedure, but my old KSS210 based player with Sony chipset has several test points in the PCB, two of which are labelled RF and RF GND. If you hook your oscilloscope probe there, you will see the actual bit stream just as it's being picked up by the data photodiode from the disc. Then, you can try to play with the potentiometers a bit trying to get more crisp square and symmetrical transistions on that waveform (remember that it's the lenght of the pulse and not the level what tells 0 from 1) . You can also try different kinds of discs (commercial silver, CD-RW, CD-R burned with computer at 4X, 8X, 16X, etc...) and you will see the actual difference on the waveform :D (no more urban legends... that experience led me to burn all my audio stuff at 8x or slower).

hiwiho 14th April 2006 07:24 PM

There is also one in my old nakamichi, i had to replace it last year and thus bought the manual. Take a look at page 9ff of this, maybe it can help?!?
http://www.listmember.de/diyaudio/se..._cdplayer4.zip

I lacked most of the equipment for precise adjust, so i "tried" carefully....

Matthias

Elso Kwak 14th April 2006 07:59 PM

Matthias, only adjust VR102 for clearest eyepattern on the scope.
You did remove the solder bubble on the flex cable?
I always forgot!
:cool:

delory 16th April 2006 10:45 PM

Hi guys,

thanks for the great responses. I was trying to do the adjustments without a scope, but I think it's time I invested in one. Most of the lasers I have adjusted have been pretty easy to get right, but this one... maybe it just needs to be really really fine tuned! I'm also having a similar problem with a kss240 in another machine, so hopefully this route will help. And thanks for the manual Matthias - very helpful.

I'll post back when (if) I make some progress. :)

anatech 16th April 2006 11:22 PM

Hi delory,
Just coming in a bit late here. The one trimmer you can easily play with is the Focus Offset control (FO in Sony chip sets). Tracking Offset and E-F Balance can get you into hot water. If you find and download some Sony CD manuals, that might help quite a bit.

After servicing CD's since they came out, I can usually set one up without worring too much about the procedure in the manual. There are times when I need the manual still. I always need my 'scope and some test discs. You can do a much better job if you use the service manual and set up jigs (if needed). For instance, I have the Nak jig for Matthias' machine. ;) , Yamaha, Denon, Philips / Revox.

Never, ever touch the pots on the head itself. :nownow: There are special situations where I might, or other service people. I never increase the current and send it out the door. (criminal)

I don't know if that's any help to you, but for what it's worth ... Don't forget to check the spindle motor. The bearings generally wear before the head does. "Random" will tear the bearings out very quickly. (I call the Random button the DIE button :D )

-Chris

Zero Cool 16th April 2006 11:32 PM

I would like to aquire a set of Sony Test Discs for the SCD-1 CD player.
Sony
SATD-S1 Optical Pickup Height Adjust disc.
SATD-S2 Reference disc single layer
SATD-S3 Reference disc dual layer
SATD-S4
and the Reference disc TCD-784

As well as speak with anyone that has done laser transplants on these beast's.


Zc

anatech 16th April 2006 11:39 PM

Hi Zero Cool,
That appears to be an expensive disc set. Once you've done a few you know which you need, and not. I haven't done these machines, nor do I have the service manual. The manual itself would help figure out which ones you actually need.

Many times a test disc may simply be assured to be "bang on spec". Many times to insure you get the same figures as the factory in setup. You may only really need a DVD setup (or SACD ? I have no clue) and normal CD setup discs.

-Chris

hiwiho 17th April 2006 11:41 AM

As for my Naka, i got used to adjust it according to the disc i'd like to hear. I don't use it very often, only for discs where i think it sounds better than my HK hd740 (both modded with a kwak clock, amazing improve btw). It's got much more attack than the 740 and a tighter
bass. I was never able to set it up correct after head replacement cuz my scope is a one-channel thing. But i can confirm that playing with especially EF is tricky :bawling: However, i have some discs where the player starts to crackle immediately (which happens with constant and high amount of high frequencies in the music) and i can trim that away with EF... I know i shouldn't.

One thing i'd like to add: The Sony chipset obviously tends to total misbehaviour if the pickup gets weak or fails. I had it drive the pickup further than to the outer edge breaking a gear wheel, all out of "stop" position garded by a sweeping noise on the signal out. It was a hard job to get a new wheel here in Berlin. There is no Naka distributor in Germany any more - i finally got a wheel at a local repair shop for Harmans - some old models use the same drive unit.

Matthias

anatech 17th April 2006 01:12 PM

Hi Matthias,
That's a Sony transport as I recall. E-F Balance running the head to the end (and stripping the gear) is normally seen with CDR's or really poor CD's. DJ's used to bring them in all the time like that.

To really trim the E-F Balance well, you can use Pierre Verany Discs with defect tracks. PV.788031 / 788032 Tracks 25~38. Use the low filter and look at the envelope. Correct the E-F Balance to give a vertical clean line and clean recovery from the data drop out. It can be difficult to get the 'scope to trigger, but once you see the pattern you will understand. That would be one of my alignment secrets. Now I have to kill you! ;)

Let me know if this works out for you.

-Chris


All times are GMT. The time now is 05:51 AM.


vBulletin Optimisation provided by vB Optimise (Pro) - vBulletin Mods & Addons Copyright © 2014 DragonByte Technologies Ltd.
Copyright 1999-2014 diyAudio


Content Relevant URLs by vBSEO 3.3.2