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Any Cambridge Audio CD2 owners here?

We had a CD2 display model with a clear Perspex top and a special switch on the back that put it into a mode where it constantly loaded and unloaded a disk to show off the mech. I seem to remember using it as a loaner for many years after we expected it to have died.
 
Just when you think you're done....

After enjoying the CD2 for a few days it became apparent that after it had been playing for more than an hour or so and was really thoroughly warmed up I was getting some static like noise on the right channel. Unfortunately that's a classic symptom of a failing TDA1541...DOH! :(

Frustratingly I couldn't replicate the fault with the player 'on the bench' no matter how long I left it to warm up. Eventually I realised that with the cover off it simply wasn't getting warm enough for the fault to appear, so I covered the DAC section with a tea towel to keep it nice and toasty. With the faulty DAC chip now warm enough to misbehave I was able to trace which DAC chip was the source of the noise using my trusty Tek scope.

Faulty chip removed.
P1100964 by Michael Pickwell, on Flickr

Heatsink/radiator removed revealing a TDA1541 (non A).
P1100965 by Michael Pickwell, on Flickr

New chip taken from my donor Philips CD371
P1100967 by Michael Pickwell, on Flickr

Soldering all done
P1100966 by Michael Pickwell, on Flickr

Aluminium strip glued back on and DAC card back in place.
P1100968 by Michael Pickwell, on Flickr

I've been listening again this morning and it sounds even better than it did before.
 
Dowser said:
Now you need to change the others to As too :)
Click to expand...

Yeah, that would be nice but given that I need four it would be pretty expensive. My TDA1541A stash has been a bit hammered lately so I don't have four matching chips I could use and would need to go shopping.

The added benefit of swapping to 'A's is that I could also upgrade to the SAA7220P/B.

Anyway, non A chips can sound really good too, my CDP-555ESD is still the best player I've ever heard and that has a non-A in it.
 
The TDA 1541 seems to be one of the very few chips that actually wears out when used normally.
I assume that the metal plate is a heatsink. If so glue is not the best method
Remaking the PCBs double sided FR4 with a ground plane on top would at least improve cooling, the original paxolin looks a bit cooked in the photo.
 
The TDA1541 normally runs warm but in the CD2 they do run a bit too hot because they used a -6v supply where you'd normally expect a -5v supply.

I'm very tempted to swap out the 7906 reg for a 7905. I don't think it would cause a problem.
 
You should make and fit a clear perspex cover so you can see early if something is cooking / smoldering, imv.

It should run the player a bit cooler if you cut some sensible vent slots.

Be Lucky. :)
 
Mike P said:
The TDA1541 normally runs warm but in the CD2 they do run a bit too hot because they used a -6v supply where you'd normally expect a -5v supply.

I'm very tempted to swap out the 7906 reg for a 7905. I don't think it would cause a problem.
Click to expand...
You are talking about -Vdd1? According to the datasheet, this should be less than -5V5. Your 7906 -6V has a tolerance too.
The datasheet has several warnings about soldering that go way beyond the usual.
Why is this voltage -6V, there must have been a good reason as the 7906 is rare and costs more than 7905
 
I had an interview with Stan Curtis when he was with Wharfedale and I was still keen to be a professional Loudspeaker designer.
Nice chap, didnt get the job.
 
Had a chance to have a quick listen to the CD2 at Mike's this morning when I took my Pioneer A27 over for a service. It's certainly got plenty of 'character' both in looks and its big bold sound.
 
I'm considering putting the CD2 up for sale to help fund a new amplifier restoration project.

If anyone is seriously interested in buying it please send me a PM.
 
After I have red Mike's work, I am following his footsteps torepair my Cambridge Audio CD2.Thanks to Mike for sharing such a nice work.. Regards...
 
After I went through the steps adviced by Mike I was able to run the CD2. In the beginning, the reading was continuously running the ERR light and the audio output was distorted. I measured the power line voltages. They were all fine. I cleaned the laser. I have changed all of the electrolytic capacitors. I have replaced all of the 74LS166 chics on the shift register board. The relay driver was not working right. I disabled it. I connected the audio output to the RCA terminals directly. I installed IC sockets for SAA7210 and SAA7220 chips. They get warm and I thought little air from the bottom would help them to cool down. I followed the service manual provided by Mike to adjust the laser focus (400 mV) and laser power (40 mV). Both displays were broken. I have ordered two new ones from Germany for 35 USD each.

After all of these affords, the CD player reproduce the music very nicely. I like its sound. Very nice and analoglike sound. However, there are minor issues.
It looks like lower focus set (280 mV) works better. I don't understand why? Conversion errors are more frequent when the device is cold. After one hour playing, everything becomes fine. Any idea?

Thanks to Mike for providing me, the very difficult to find service manuals and his usefull check up procedures...
 
It sounds like you're making good progress there. :)

When you say that you've replaced the electrolytic capacitors do you really mean absolutely all of them, including the ones on the CDM2 board?

I think it would also be worth oiling the bearings on the turntable motor.
 
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