My TEAC VRDS-10 is refusing to read a few discs - most notably hybrid SACD/CDs and CDRs. The problem seems to affect more discs when the player is switched on from cold. After a few minutes warm up some of the affected discs will then be read and will play OK.
The player had a full service two years ago, so the laser should be OK. Please can anyone suggest what I might need to look at first to solve the problem?
John
The player had a full service two years ago, so the laser should be OK. Please can anyone suggest what I might need to look at first to solve the problem?
John
perhaps an idea....
I'm no expert, but perhaps the laser bias voltage might need to be adjusted. Same thing happens to the Sony greystations when used as a cd player (there is a long thread here at diyaudio about that topic, see Playstation as CD player .
Don't know the specs or where to adjust it on the big TEAC, but I think that could be a start.
stew
I'm no expert, but perhaps the laser bias voltage might need to be adjusted. Same thing happens to the Sony greystations when used as a cd player (there is a long thread here at diyaudio about that topic, see Playstation as CD player .
Don't know the specs or where to adjust it on the big TEAC, but I think that could be a start.
stew
Hi John,
Don't touch the laser power adjust.
Use an oscilloscope and look a the eye pattern first. Look at some CDs you have no trouble with (and compare that with the information in the manual), then look at the skipping ones. You need to see what is changing about the eye pattern. Could be jitter, amplitude or just excessive noise. You have got to find out what your problem is before you start doing stuff.
If I had the manual, I could have given you specific things to look for. If you can scan a couple things, I may be able to help there.
-Chris
Don't touch the laser power adjust.
Use an oscilloscope and look a the eye pattern first. Look at some CDs you have no trouble with (and compare that with the information in the manual), then look at the skipping ones. You need to see what is changing about the eye pattern. Could be jitter, amplitude or just excessive noise. You have got to find out what your problem is before you start doing stuff.
If I had the manual, I could have given you specific things to look for. If you can scan a couple things, I may be able to help there.
-Chris
TEAC
Hi,
First of all, make sure the KSS-151A (laser unit) can glide easy on the shiny rod and make sure this rod is clean and apply just a little bit of thin oil on it and make sure it glides like if it's floating!
Second, make sure you DO NOT turn anything unless you know what you're doing.
Third, make sure the flat cable that is attached to the KSS-151A is hanging free and is not bend or broken and well connected to the connectors on the PCB's.
last, keep us posted
I hope this will help you fix the player.
All the best,
Audiofanatic
Hi,
First of all, make sure the KSS-151A (laser unit) can glide easy on the shiny rod and make sure this rod is clean and apply just a little bit of thin oil on it and make sure it glides like if it's floating!
Second, make sure you DO NOT turn anything unless you know what you're doing.
Third, make sure the flat cable that is attached to the KSS-151A is hanging free and is not bend or broken and well connected to the connectors on the PCB's.
last, keep us posted
I hope this will help you fix the player.
All the best,
Audiofanatic
my suggestions....
were just that, only suggestions.
anatech:
As I stated, I'm no expert (and I know you are very experienced, so I defer to you). My comment was based on my personal experience with some cd players and the greystations---that's it. Adjusting the bias to the laser focuses it, if I understand correctly.
Audiofanatic : Obviously I would never suggest anybody adjust anything if they are unsure. I have no interest in causing a catastrophic failure in anyone's equipment. And of course checking all the mechanical connections and mechanics is always a good (and easy) place to start.
jonners : know I would never intentionally steer you or any wrong
stew.
were just that, only suggestions.
anatech:
As I stated, I'm no expert (and I know you are very experienced, so I defer to you). My comment was based on my personal experience with some cd players and the greystations---that's it. Adjusting the bias to the laser focuses it, if I understand correctly.
Audiofanatic : Obviously I would never suggest anybody adjust anything if they are unsure. I have no interest in causing a catastrophic failure in anyone's equipment. And of course checking all the mechanical connections and mechanics is always a good (and easy) place to start.
jonners : know I would never intentionally steer you or any wrong
stew.
Hi Stew,
Hey, no problem. However you should never adjust anything until you have instructions (or know exactly what you are doing through experience).
I think you were talking about the focus bias. You can, but you must be able to see the RF pattern in order to assess how your efforts are affecting the unit.
Hi Audiofanatic,
Good points.
The "glide test" can only be performed with the power off and the head released from it's parking position. Check both sides for effortless movement with no snags anywhere.
Hi John,
Another test you can make is to check for vibration as the disc is rotating in play mode. Any vibration at all will point to either a bad disc motor bearing or clamper assembly bearing. That entire rotating mass is heavy and make wear the thrust bearing or a sleeve bearing. On a rebuild, these things should have been done as well.
-Chris
Hey, no problem. However you should never adjust anything until you have instructions (or know exactly what you are doing through experience).
I think you were talking about the focus bias. You can, but you must be able to see the RF pattern in order to assess how your efforts are affecting the unit.
Hi Audiofanatic,
Good points.
The oil must be a single weight, fine oil with no additives what so ever. It's important to clean the old oil off first, completely. That means taking this apart, and I don't recommend you do that. The flat cable is easy to tear if you catch it on something. There is also a shorting area to protect the laser diode if you disconnect this cable. Do not touch the lens.
The "glide test" can only be performed with the power off and the head released from it's parking position. Check both sides for effortless movement with no snags anywhere.
Now, how could anyone disagree with that! I don't think that point can be made often enough.
Hi John,
Another test you can make is to check for vibration as the disc is rotating in play mode. Any vibration at all will point to either a bad disc motor bearing or clamper assembly bearing. That entire rotating mass is heavy and make wear the thrust bearing or a sleeve bearing. On a rebuild, these things should have been done as well.
-Chris
Thanks, guys for all your suggestions - this is all very helpful.
One thing I've noticed, which might be significant, is that if I touch the flat cable and move it slightly during play the disc will stop reading, and will resume after a couple of seconds of silence.
tvi -
The manual would be a great help, thanks. Could you email me the sections that are likely to be relevant?
John
One thing I've noticed, which might be significant, is that if I touch the flat cable and move it slightly during play the disc will stop reading, and will resume after a couple of seconds of silence.
tvi -
The manual would be a great help, thanks. Could you email me the sections that are likely to be relevant?
John
You can download the file from
http://www.fileqube.com/file/eNtxAmvsy169716
its 7.7meg
Hope it helps
Regards
James
http://www.fileqube.com/file/eNtxAmvsy169716
its 7.7meg
Hope it helps
Regards
James
Progress
James - thanks for that. Brilliant!
I'm making progress. I was using the player as a transport and it had a Trichord clock that was connected via a NetAudio reclocking digital out board. I removed the latter and reconnected the Trichord clock direct to the main board.
Following this things have improved, and the only disc I can find which the player won't read is a hybrid SACD/CD entitled "Death and Devotion". Quite possibly the player finds the title so depressing that it just doesn't want to go there.
Chris - my scope is an ancient, pre-digital age job. Fastest timebase is 1usec/cm. Probably no use here?
Audiofanatic - thanks for your help. Is it normal for the flat cable to be so sensitive to being moved, as I described in my last post?
Stew - thanks for helping. No harm done!
James - thanks for that. Brilliant!
I'm making progress. I was using the player as a transport and it had a Trichord clock that was connected via a NetAudio reclocking digital out board. I removed the latter and reconnected the Trichord clock direct to the main board.
Following this things have improved, and the only disc I can find which the player won't read is a hybrid SACD/CD entitled "Death and Devotion". Quite possibly the player finds the title so depressing that it just doesn't want to go there.
Chris - my scope is an ancient, pre-digital age job. Fastest timebase is 1usec/cm. Probably no use here?
Audiofanatic - thanks for your help. Is it normal for the flat cable to be so sensitive to being moved, as I described in my last post?
Stew - thanks for helping. No harm done!
More progress (maybe)
With the help of the manual I checked the sled balance with my DVM, and my scope was good enough for me to be able to do the tracking balance and focus balance adjustments.
Magic! Player will now deliver "Death and Devotion" without going into terminal depression.
EDIT: Correction, it will only play this disc if the scope is still connected to the test point for checking focus balance. After disconnecting the scope the player reverts to its refusal to read the disc. How weird is that?
Adjustments to focus gain and tracking gain appear to require the use of a test disc:
"Apply 1.07kHz/10Vp-p to TP1 pin1 from an external oscillator via a 100k resistor. Play track 4 and adjust F.Gain so that phase at TP1 pin2 is 90deg with respect to that of the external oscillator."
Can anyone deduce from the above what is likely to be on track4 of the test disc?
John
With the help of the manual I checked the sled balance with my DVM, and my scope was good enough for me to be able to do the tracking balance and focus balance adjustments.
Magic! Player will now deliver "Death and Devotion" without going into terminal depression.
EDIT: Correction, it will only play this disc if the scope is still connected to the test point for checking focus balance. After disconnecting the scope the player reverts to its refusal to read the disc. How weird is that?
Adjustments to focus gain and tracking gain appear to require the use of a test disc:
"Apply 1.07kHz/10Vp-p to TP1 pin1 from an external oscillator via a 100k resistor. Play track 4 and adjust F.Gain so that phase at TP1 pin2 is 90deg with respect to that of the external oscillator."
Can anyone deduce from the above what is likely to be on track4 of the test disc?
John
Hi John,
You are using a 10:1 probe - right? Otherwise your probe and scope will load down the circuit and your adjustments might be off as a result. Never, ever use a 1:1 probe except in very specific instances. Then, a 50 or 75 ohms termination will probably be in use.
Figure 4-8 is the RF pattern / eye pattern. Each "diamond" is referred to as an eye.
-Chris
Edit: James, excellent! Thank you very much.
Does Teac supply their manuals on PDF these days for new product?
You are using a 10:1 probe - right? Otherwise your probe and scope will load down the circuit and your adjustments might be off as a result. Never, ever use a 1:1 probe except in very specific instances. Then, a 50 or 75 ohms termination will probably be in use.
DVMs are prone to giving the wrong reading when you have a fair amount of noise. That's a good time to use the 'scope and set your zero (or whatever level) to the center of the "fuzzy" display.
The information on the track is irrelevant, It's the physical characteristics of that disc that is important. This is also why you can't make your own test disc. Ignore that step for now. Focus and tracking gain are not too finicky and you will probably put it out more if you try to set it without the proper disc.
A little harder to see the eye pattern clearly, but it should do fine. You actually should have 0.5 uS / Div to see the eye pattern clearly. 10 MHz 'scope? Could be an early 20 MHz 'scope also.
Absolutely, yes. You are injecting a ton of noise and also affecting the signal capacitively. Watch the eye pattern and do this slowly.
Figure 4-8 is the RF pattern / eye pattern. Each "diamond" is referred to as an eye.
-Chris
Edit: James, excellent! Thank you very much.
Does Teac supply their manuals on PDF these days for new product?
Hello,
I am trying, as a beginner, to adjust with a scope according to the manual.
I just don't get what it says, like for example:
"check for an offset voltage of 50mV or less at tp3".
Since there is only one pin on tp3, how do I do that?
And another thing: the manual says: "adjust f.gain so that phase at tp1 pin2 is 90° with respect to that of the external osc during playback".
I understand that I need a sound generator, so I bought that.
I also understand that I need an osc, so I bought that.
I just don't know what those 90° means when looking at the display of the scope?
And I don't understand the wire going from the scope to the tp1 pin2. What does it do and how to connect it? I mean there are a wire + gnd on a shielded cable for a channel on a scope. Is it som sort of trigger wire? Or something else? And how to do it?
Finally, in which of the test and adjustment procedures should i play a cd? Sometimes it is not mentioned. I think I read somewhere that one does not need the specific test cd, but can use a music cd. If I did that, would it then give some wild fluctuations on the scope, instead of a more steady wave on the display when using a test cd?
Kind regards,
sfc1000
I am trying, as a beginner, to adjust with a scope according to the manual.
I just don't get what it says, like for example:
"check for an offset voltage of 50mV or less at tp3".
Since there is only one pin on tp3, how do I do that?
And another thing: the manual says: "adjust f.gain so that phase at tp1 pin2 is 90° with respect to that of the external osc during playback".
I understand that I need a sound generator, so I bought that.
I also understand that I need an osc, so I bought that.
I just don't know what those 90° means when looking at the display of the scope?
And I don't understand the wire going from the scope to the tp1 pin2. What does it do and how to connect it? I mean there are a wire + gnd on a shielded cable for a channel on a scope. Is it som sort of trigger wire? Or something else? And how to do it?
Finally, in which of the test and adjustment procedures should i play a cd? Sometimes it is not mentioned. I think I read somewhere that one does not need the specific test cd, but can use a music cd. If I did that, would it then give some wild fluctuations on the scope, instead of a more steady wave on the display when using a test cd?
Kind regards,
sfc1000
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