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  1. #1
    cod
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    Unhappy AH Njoe TJoeb problem, please help an idiot

    Hi there

    I have owned one of these fine TUbe output CD players for about 4 years now, all was well up until this morning and i would be very appreciative of any insights you may have. I bought a CD, that i played this morning and i could only hear the right channel.

    Now stupidly I took the cover off thinking it was the tubes, that one had gone. So i got an old pair of Philips tubes that come with the CD player, and tried them, still no luck!.

    on the control board and im no expert at these things, but there are 2 DIL Burr brown opamps, set parralel to one another, i thought one of those might be the problem. There was also another small chip of the same size i think is the DAC chip. I took them out reseated them, changed them round.

    Maybe stupidly the wrong way round, the opamps have 8 pins 1- 4 5 - 8 I turned them round only because I forgot which way they went round. I usually do a little diagram before undertaking such work, but alas i didnt, fool!. Well the thing is it was the bloody Cd that was at fault. Overjoyed when I played my Meddle Album, In perfect stereo, was really happy. But to my horror... now at low levels i get a distortion sound and a slight ghosting of a high pitch sine wave around the 6th octave of a piano.

    It cuts out after certain low passages break into higher volume. but ambient music is awash with this distorted tone. I know the tubes all work, I know the fuse is good, Im just wondering if i have damaged the opamps, or the circuit board. and to be really stupid i turned the DAC chip round the wrong way, (I wish i had done my usual ritual of making notes)

    heaven help me if i have , i have to send it back to holland to be fixed if its not a straight replacement

    so guys any insight would be much appreciated
    Andy

  2. #2
    Santa Claus
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    Quote Originally Posted by cod
    Hi there

    I have owned one of these fine TUbe output CD players for about 4 years now, all was well up until this morning and i would be very appreciative of any insights you may have. I bought a CD, that i played this morning and i could only hear the right channel.

    Now stupidly I took the cover off thinking it was the tubes, that one had gone. So i got an old pair of Philips tubes that come with the CD player, and tried them, still no luck!.

    on the control board and im no expert at these things, but there are 2 DIL Burr brown opamps, set parralel to one another, i thought one of those might be the problem. There was also another small chip of the same size i think is the DAC chip. I took them out reseated them, changed them round.

    Maybe stupidly the wrong way round, the opamps have 8 pins 1- 4 5 - 8 I turned them round only because I forgot which way they went round. I usually do a little diagram before undertaking such work, but alas i didnt, fool!. Well the thing is it was the bloody Cd that was at fault. Overjoyed when I played my Meddle Album, In perfect stereo, was really happy. But to my horror... now at low levels i get a distortion sound and a slight ghosting of a high pitch sine wave around the 6th octave of a piano.

    It cuts out after certain low passages break into higher volume. but ambient music is awash with this distorted tone. I know the tubes all work, I know the fuse is good, Im just wondering if i have damaged the opamps, or the circuit board. and to be really stupid i turned the DAC chip round the wrong way, (I wish i had done my usual ritual of making notes)

    heaven help me if i have , i have to send it back to holland to be fixed if its not a straight replacement

    so guys any insight would be much appreciated
    Andy
    That's it?What a round about way of finding the problem.I had a problem with some CD's on my CD player not being recognized.However,I didn't take the whole unit apart.I mean I was a little scared but not on the brink of paranoia.I suppose you learned a lesson.Holy cow,I'm glad i'm not in your situation as i'm certainly no mechanic.Keep me posted as to the outcome.Also it's four years old, maybe a replacement?

  3. #3
    Suspended markw's Avatar
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    Insight? You want a little insight? A little late, but here it is.

    In most cases, when a problem arises, it often stems from the latest addition to the signal chain. Always look there first for the source of the problem.

    In this case, that would be the new CD.

    The first thing I would have done is try another (known working) CD in the CD player.

    The second thing I would have done is try that new CD in another (known working) CD player.

    The absolute last thing I would have done is to vivisect the CD player, or anything, without first isolating the culprit. That problem could have come from any link in the chain.

    At least you learned a lesson, I hope. Sometimes the best learned lessons are those that cost the most.
    Last edited by markw; 05-13-2006 at 10:30 AM.

  4. #4
    cod
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    Wink

    Im usually not so careless. But in my defence, I now know that even before i took the Cd player apart, there was a sibilance in the background. There was a fault in the DAC chip.
    I also thought as the tubes had lasted a few years, that one had gone.

    But christ knows why i didnt put another CD in, silly arse!.

    But good news, i got a replacement Dac, got new opamps, and even bought some more to put into my Rotel pre amp, and now that sounds better!, and everythings round the right way!. I am also going to, (and stick them in the right way), put some BB OPA627,s in the Cd player.

    I know i did wrong, I just thought you might wanted to have some other idiot apart from yourself to laugh at, *smiles*

    Seriously though, Im so happy my CD players working, and Im afraid, even if it was over 20 years old, I wouldnt buy a replacement until its truly dead, for one i cant afford it at the moment. And two, it sounds lovely.

    (be sticking a CD on a turntable next)

  5. #5
    Santa Claus
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    Quote Originally Posted by cod
    Im usually not so careless. But in my defence, I now know that even before i took the Cd player apart, there was a sibilance in the background. There was a fault in the DAC chip.
    I also thought as the tubes had lasted a few years, that one had gone.

    But christ knows why i didnt put another CD in, silly arse!.

    But good news, i got a replacement Dac, got new opamps, and even bought some more to put into my Rotel pre amp, and now that sounds better!, and everythings round the right way!. I am also going to, (and stick them in the right way), put some BB OPA627,s in the Cd player.

    I know i did wrong, I just thought you might wanted to have some other idiot apart from yourself to laugh at, *smiles*

    Seriously though, Im so happy my CD players working, and Im afraid, even if it was over 20 years old, I wouldnt buy a replacement until its truly dead, for one i cant afford it at the moment. And two, it sounds lovely.

    (be sticking a CD on a turntable next)
    Thanks for the update.My God you must have an engineering degree or something.If something like that happened to my cd player I'd be in a state of panic.Good luck

  6. #6
    cod
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    Wink

    Oh god no, If i had an engineering degree, and made that booboo.....

    Its a simple case of necessity. I learn what i have to or want to, to get what I want. anyone can replace opamps, ehm, the right way round of course, I can work on instruction and solder a whole amp, if its precise, but ask me to tell you what every component is doing, i wouldnt have a clue. Schematics, forget it. But I may just take up a course on reading schematics, and electronics. It looks like a language of symbols, that can be learnt. there again, Im not too great at concentrating and my head flitters, so, im more likely to set fire to something. Or blow it up

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