Thanks for the hint.
Well, I've totally dismanteled it on saturday. Cleaned it, and added a bit of grease. Then I put everything back in place, and tested it : no more problem fully listenning at 5-6CDs at least.
Then Sunday, it started again, and by the end of the day, it was even worse. So I'm thinking about opening it again, and cleaning again but not add any grease, just perfect cleaning.
I also started modding it... I disabled the headphone circuit as suggested by Ray and many other : "Disable headphone circuit: remove C901/902 (signal) and jumpers U271/272 (+/- 12V)."
Well, I've totally dismanteled it on saturday. Cleaned it, and added a bit of grease. Then I put everything back in place, and tested it : no more problem fully listenning at 5-6CDs at least.
Then Sunday, it started again, and by the end of the day, it was even worse. So I'm thinking about opening it again, and cleaning again but not add any grease, just perfect cleaning.
I also started modding it... I disabled the headphone circuit as suggested by Ray and many other : "Disable headphone circuit: remove C901/902 (signal) and jumpers U271/272 (+/- 12V)."
).
I have just changed my CD drive with a brand new VAM 1201 but unfortunately there are skipping issues (sometimes) in certain tracks when playing back CDs.
With my ohm meter in hand I found the total resistance of the trimming VR was 8.8K and the stock setting was half which is 4.4K. I then turned the VR clockwise by a small bit to make it 4.9K which I believe has slightly increased the laser diode voltage. With that there is no more skipping of tracks
With my ohm meter in hand I found the total resistance of the trimming VR was 8.8K and the stock setting was half which is 4.4K. I then turned the VR clockwise by a small bit to make it 4.9K which I believe has slightly increased the laser diode voltage. With that there is no more skipping of tracks
Where is that VR ? I'd like to check it.
I've played just one CD yesterday evening, but it didn't skip at all.
I've already ordered a VAM1201, but if my pb can be solved with a good cleaning (not yet done) and a VR adjustement
Just take out the entire drive and invert it and look at the bottom side of it. You will see the brown color flexible PCB of the laser unit and in the middle of it you will see something like a small screw (that was what I had thought initially) but if you look at it carefully it is actually a trimming VR with 3 connections. Before you adjust it use a ohmmeter to note down the stock resistance so that you can revert it back if you wish. Then turn the VR by a small bit clockwise and measure the resistance. Don't turn the VR by too much as a high voltage to the laser diode will shorten its life. Hope the above can help and please report back if the problem of skipping is solved.
That vr is factory set. Increasing it without using a test disc and a scope will short life the new laser (i know this from personal experience)
Its more likely that the height of the CD mount on the spindle is incorrect and lifting it slightly away from the mech will give the same results. All the problematic mech's I've had (apart from the one where I blew up the diode) have been resolved this way.
Its more likely that the height of the CD mount on the spindle is incorrect and lifting it slightly away from the mech will give the same results. All the problematic mech's I've had (apart from the one where I blew up the diode) have been resolved this way.
Another CD63 mod
Surprisingly there have not been a lot of discussions in this forum for a number of days
.
To add something to this page let me say that I have just completed 90% of modding work on my friend’s CD63 (I have promised him to carry out the modification before X’mas). The only outstanding work now is to add a low jitter clock to the servo and the decoder. I have just purchased one in the eBay and it should arrive in a week or two.
For this CD63 I swapped the stock transformer with my spare toroidal transformer from my KI. As my friend will normally use this CD63 as a transport so I did not add a lot of enhancement to the analogue section. I just changed the smoothing caps (Panasonic TSUP and FC) and changed a lot of critical caps in the circuit. I have also changed the opamp with 4652HA. To improve the transport performance I add a 50VA 2X12V toroidal transformer to drive the servo section. I also add a relay operated muting circuit and replaced the 5V regulator 7805 with a low noise regulator to supply low noise stable voltage. As my friend has limited budget so I did not use top of the grade components or individual regulators but the SQ from this unit (without the low jitter clock at the moment) is very good indeed.
I will provide update when the clock is added.
Surprisingly there have not been a lot of discussions in this forum for a number of days
.To add something to this page let me say that I have just completed 90% of modding work on my friend’s CD63 (I have promised him to carry out the modification before X’mas
). The only outstanding work now is to add a low jitter clock to the servo and the decoder. I have just purchased one in the eBay and it should arrive in a week or two.For this CD63 I swapped the stock transformer with my spare toroidal transformer from my KI. As my friend will normally use this CD63 as a transport so I did not add a lot of enhancement to the analogue section. I just changed the smoothing caps (Panasonic TSUP and FC) and changed a lot of critical caps in the circuit. I have also changed the opamp with 4652HA. To improve the transport performance I add a 50VA 2X12V toroidal transformer to drive the servo section. I also add a relay operated muting circuit and replaced the 5V regulator 7805 with a low noise regulator to supply low noise stable voltage. As my friend has limited budget so I did not use top of the grade components or individual regulators but the SQ from this unit (without the low jitter clock at the moment) is very good indeed.
I will provide update when the clock is added.
Attachments
Case damping
Hi,
What's good stuff to use for case damping nowadays, and where do you get it from in UK?
Up until now I've been using Brown Bread which I got a roll of years ago but it's run out and I can't find it anymore.
The first KI that I sent off to be modded came back with a cork floor tile glued to the inside of the lid which seems a good cheap solution if nothing else.
Regards
Pete
Hi,
What's good stuff to use for case damping nowadays, and where do you get it from in UK?
Up until now I've been using Brown Bread which I got a roll of years ago but it's run out and I can't find it anymore.
The first KI that I sent off to be modded came back with a cork floor tile glued to the inside of the lid which seems a good cheap solution if nothing else.
Regards
Pete
