Magnavox CDB 500.......

Discussion in 'Digital Sources' started by AK 47, Aug 2, 2010.

  1. AK 47

    AK 47 Well-Known Member

    Messages:
    649
    Location:
    Parma, ID USA
    I picked one up in the thrift and have used it for several days and it plays/sounds great. It uses a CDM4/19 transport.

    [​IMG]

    My question is: Is there any maintenance I need to perform on the 'swing arm' transport? Clean, lube? I would like to keep this thing going for awhile. Thanx much, Chuck
     

     

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  2. willhowl

    willhowl Well-Known Member

    Messages:
    856
    Location:
    Houston, Texas
    Cool CD!!!!

    Howdy,AK47.......Congrats on your find..... I don't have any specific info for you, but if you search for CD maintenance,I'm sure you will find info.......

    My comment is that these old Magnavox decks DO sound amazingly good, and read CDs VERY well.....even home-burned CD-Rs.......I've got two now, and am always looking for 'em out in the wild.........


    By all means, read up, and keep it running............willhowl:thmbsp:
     
  3. Tinman

    Tinman AK Subscriber Subscriber

    Messages:
    3,083
    Location:
    Los Angeles, California.
    Generally, No. Just keep the lens clean.

    When it DOES act up, then worry about it. Only the really old one's need capacitors now.
     
  4. gearhound

    gearhound Lunatic Member

    Messages:
    10,115
    Location:
    Santa Fe, New Mexico
    I bought my Magnavox CDB-460, new in March of 1988.
    It's has been a DAILY player ever since.

    I'm STILL waiting for the FIRST skip on a disc!!??

    Steve
     
  5. audiozaz

    audiozaz rtfm!? - tl;dr

    Messages:
    3,361
    Location:
    Eastern Townships, Québec
    Congratulations!

    I too grabbed a CDP-502 a while ago, nice swing-arm mechanism and TDA1543 DAC. Sound pretty good as it is, but I'll do some mods on it for kicks. You gotta love sleepers!

    az
     
  6. audiozaz

    audiozaz rtfm!? - tl;dr

    Messages:
    3,361
    Location:
    Eastern Townships, Québec
    I tried my CDB 502 some more last night and it read flawlessly some damaged CD's that my other players skipped on. Ain't Philips mechanisms great?

    az
     

     

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  7. Robint

    Robint Well-Known Member

    Messages:
    634
    Location:
    Wilmore KY
    I too just picked up a Magnavox cd player from a local thrift. It's a CDB496, a six disc changer using TDA1543's. I must say I prefer the sound to the Sony I was using. I will be keeping a lookout for Magnavox players.
     
    Last edited: Nov 13, 2010
  8. audiozaz

    audiozaz rtfm!? - tl;dr

    Messages:
    3,361
    Location:
    Eastern Townships, Québec
    AK47,

    The service manual for the Philips CD500/502 (same thing as Magnavox CDB's) is on hifiengine.com IIRC. Could come in handy. PM me if you don't find it.

    az
     
  9. AK 47

    AK 47 Well-Known Member

    Messages:
    649
    Location:
    Parma, ID USA
    tried hfe and couldn't locate anything on Magnavox or Phillips 500 series?:no:

    Also, :sigh: , I have another CDB 500 coming.:yes: I liked the one I have so much that I decided To get another for mods or?:scratch2:
     
  10. guiller

    guiller Toscaninichus Australis

    Messages:
    21,422
    Location:
    Buenos Aires (Argentina)
    The only one I've found listed there is the Philips cd582 model
    http://www.hifiengine.com/manuals/philips/cd582.shtml

    On the other hand, the service manual for the Philips CD500 is listed in the Philips-Marantz site, but it is not free: http://www.marantzphilips.nl/philips_service_manuals/
     
  11. audiozaz

    audiozaz rtfm!? - tl;dr

    Messages:
    3,361
    Location:
    Eastern Townships, Québec

     

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  12. AK 47

    AK 47 Well-Known Member

    Messages:
    649
    Location:
    Parma, ID USA
    Got it, and I thank you very much:thmbsp:. Chuck
     
  13. Tinman

    Tinman AK Subscriber Subscriber

    Messages:
    3,083
    Location:
    Los Angeles, California.
    The Philips mechs were the best ever made. :thmbsp:

    Eventually they were phased out in another effort to "maximize profits".

    And so it goes.

    Marc
     
  14. audiozaz

    audiozaz rtfm!? - tl;dr

    Messages:
    3,361
    Location:
    Eastern Townships, Québec
    That's what I love about these older machines, they were definitly "low-end", but buillt with good mechanisms that you'd have to pay much more today to get equivalent.

    I did some mods on my CDB-502 the past weekend. I removed the muting transistors on the output, changed the 1k output resistor for a 147ohm 1% unit and augmented the 10µF output cap to a 100µF NP electro to bring back the LF rolloff to a ridiculously low value. This mod was done as a way to reduce the output impedance of the CDP so it can drive the input of a step-up transformer in a passive pre. Except for the very lowest volume control positions, it will drive much higher loads and be OK. I checked and even if I do short the output (VC all the way down) the output op-amp should be able to take it. If the experiment is a success, I'll replace the cheap LM833 op-amp with something better.

    az
     
  15. AK 47

    AK 47 Well-Known Member

    Messages:
    649
    Location:
    Parma, ID USA
    Hi az.........hope you documented these mods with pic's(especially the muting xistors). I am supposing that on my Phillips 500 wiring diagram the muting xistors are 7684 and 7685. Did you just snip the collector lead or remove the whole device?


    as I would like to do the same. :yes: Chuck
     
    Last edited: Aug 23, 2010
  16. audiozaz

    audiozaz rtfm!? - tl;dr

    Messages:
    3,361
    Location:
    Eastern Townships, Québec
    Yes, 7684 and 7685 it is. They are tiny-ass surface mount parts on the "underside" of the board. I say this with " " because the board is actually mounted upside down in the chassis. I removed them completely. When I did that on my Philips CD921, I could now hear noises and clicks when skipping tracks, turning on/off the player, but the Magnavox CDB-502 is still quiet during the same operations.

    I did not take any pics for that, but they should be fairly easy to find, the silkscreening is pretty clear on those boards. I don't even know if I will keep the mods to the output (resistor and capacitor), depends on if I can make my passive-pre with step-up transfos work and, after what I tried last evening, I have a problem that stomps me big time... But I have a few things I know to look at before I give up!

    az
     

     

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  17. AK 47

    AK 47 Well-Known Member

    Messages:
    649
    Location:
    Parma, ID USA
    well thanx much for the quik response..........I've got my second 500 coming in tomorrow. I get my 'scaple' ready. If I do anything beyond that it might be 'lampizatoring' it (if I can relocate the website.:D
     
  18. Dr Tinear

    Dr Tinear AK Subscriber Subscriber

    Messages:
    5,152
    Location:
    Livonia, Michigan
    I have a CDB-502 modded by Frank Van Alstine and a CDB-650 (currently out of commission, alas) that I modded years ago. In my experience, changing the op amps and bumping up the local decoupling capacitance at the op amp chips will give you more improvement than the things you've already done. I used Analog Devices AD827 duals on the '650 project and was very pleased with the sound. There may be newer devices out there that sound as good or better.

    I visited the lampizator's Web site and was not impressed with his technical acumen (or lack thereof, more accurately). Anybody who recommends running a TDA1541 or TDA1543-based DAC without an analog filter at its output is asking for trouble. The image energy at multiples of 176.4 kHz needs to be attenuated to keep it from overdriving preamp or amp circuits in the ultrasonic range or frying tweeters.
     
  19. audiozaz

    audiozaz rtfm!? - tl;dr

    Messages:
    3,361
    Location:
    Eastern Townships, Québec
    I did not do these mods for improvement in sound quality, but to reduce the CDP's output impedance for a special purpose.

    Once I get my current projects done, I might consider modding this little sleeper, which BTW, sounds pretty good to start with!

    az
     
  20. AK 47

    AK 47 Well-Known Member

    Messages:
    649
    Location:
    Parma, ID USA
    Well, got my other CDB500 today and quickly did the muting transisters surgery (I just heated the collector joints and rolled them back. 7684 near the dog leg corner, 7685 near the second pic corner.
    Both Maggies sound wonderful, but I wouldn't be typical unless I said the bass of the moded unit did project a more real picture. Gary Jess's 'Lady of the Lake' relies much on the 'bass' riverboat horn.:music:
     

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