SONY CDP101 Modification

Discussion in 'Solid State' started by atcgreg, Feb 23, 2009.

  1. atcgreg

    atcgreg New Member

    For those that still have the CDP101 and love it.

    I would like to share my experience with modifying my 1984 CDP101 CD player.
    First of all I did not encounter any problems with the tray or servo mechanism of the player mainly because it was already with the "new" IC BX2101 that replaced the one that overheated at times and gave "the skipping" effect.
    So I was lucky to get one already fixed but back to the subject.
    The mods are rather simple and straight forward but improves the sound dramaticaly. I have removed the Opamp/buffer NE5532 jelly bean opamp,in 1984 considered as the top IC for DAC buffer's (IC 514 in the service manual) and replaced it with a specially designed opamp for HifI and Hi-end amplifications / buffer by National Semiconductor LME49720 if you can get the expensive one in a ceramic case (DIP8) around $150USD go for it that's the best. You can also get the cheaper version in a "plastic" case and it still does wonders. only one is needed. I bought mine on Ebay (USA) for $15 bucks for four it was a good bargain!! I have also used OPA2104 and OPA2134but the sound was dull without detail. With the LME49720 in place the sound is open, more air and much more detailed treble /mids. The bass is still smooth but controlled. Of course that is not only the item that was changed.
    In the power supply change the diodes to Schottky type I used 1N5819. This cleans the background of the music and really makes it "black" . On top of that the 3300uf/25v caps in the supply to 10000uf/25v there is room to accommodate them. It is only hard to get the old ones out since they were glued to the board. Also change the +/- 12v /5v supplys to better regs like Low noise, fast response voltage regulators from AUDIOUPGRADES No need for any other mods since the schematics are very good in the analog output /buffer ( without caps).!!! Oh I almost forgot I replaced the power cable and fitted a furutech socket in the back. Needs some metal cutting but it is worth it. If you still want to keep the CD 100% vintage than just repalce the cable to a larger diameter with a shielding (ground).
    I have the Sony hooked up with Van den Hul "The First" (also works good with KLOTZ "La Grange" interconnect) to my CAYIN A50T (EL34B) integrated tube amp with DIY speakers (clones of Proac). The sound is great and listening for hours does not give a headache or fatigue. I can supply for free the CDP101 service manual via email. Hearing is believing I can say after this mod the player can stand up to CD player's in the hi-end shelf. I did compared it with my friend's WADIA 301. He was impressed by the 25 year old CD . In my own subjective way I think that WADIA had a bit better focus on stereo image, as for music CDP101 was very close and it suits me. I got the whole mod for around 200euros. He got his WADIA for ten times more.

    nuff said. here is the link to data on LME49720 check it out it is worth it.

    all the best:music:
    Last edited: Apr 3, 2009
  2. dr*audio

    dr*audio Fish fingers and custard! Subscriber

    This backs up my theory that most of the "bad sound" that some audiophiles attribute to CDs is caused by the lousy opamps used in many players. I have made huge improvements to the sound of players by replacing the opamps with better ones.
  3. atcgreg

    atcgreg New Member

    Yes I totaly agree and may I add that a non-oversampling dac that CDP101 has a big impact on the sound. The next step that i did was replacing the LF353H opamps in the line analog stage with OPA627 which are faster better quality. Just need to remeber to set the offset votage to 0 volts to get the best lowest distortion and cross talk between l/R channels

  4. atcgreg

    atcgreg New Member

    Just to make it clear if anyone wants to do the mods on CDP101. The OPA627 is a single opamp so you need two of them to replace one LF353H. there are many smd OPA627 on a special adapter board on Ebay. It works fine and further improves the sound.

    Ol'skul rulz

  5. atcgreg

    atcgreg New Member

    Futher mods of SONY CDP101

    As I mentioned that the OPAMP change makes a great difference but changing the master clock to a reference low jitter one truly gives a kick in the resolution of the bits in this machine.The sound is more coherent saying it in simple words you get a sound stage that is live and well placed. Before the replacement of the clock i would say the sound stage was a bit smeared you could hear the music with good definition of instruments but without pinpoint accuracy. I used the KWAK clock. Be careful CDP101 has two clocks one 8.6Mhz.for the DAC and strange (never seen it in other cd players) 35.022Mhz in the filter switching stage. Why the KWAK clock well I just happened to have one and the best thing about the clock is that you can swap the xtal :thmbsp:in my case i used the original xtal from the PCB CDP101. I just changed the one in the dac section. Works wonders to the sound and maybe it's my imagination but fast forward and skipping to the next track on a CD is quicker:tresbon: I have two more not modified CDP101 to compare with and it does seem to improve the response time.
    Of course not mentioning the improvement in sound.:music:
    One more thing their isn't much room to put the clock in so i just used distancing (plastic tube feet 5mm) screwed to the PCB clock and glued to PCB of the SONY.If some one is interested i can attach photo's
    Till next time and happy mods to all follower's
  6. 240sx4u

    240sx4u AK Subscriber Subscriber

    Kick in the bits? awesome.

    this is pretty interesting stuff.....
  7. KentTeffeteller

    KentTeffeteller Gimpus Stereophilus!

    I think the 2 biggest things to do to improve about any CD player would be to upgrade the opamp chips and to improve the output stages.
  8. atcgreg

    atcgreg New Member

    A true statement but it takes a lot of trail and error way to judge which one is the best.:thumbsdn::thmbsp: I would have tried the BURSON discrete opamp knowing how good they are but there is no room for it.:scratch2: So second best is LME49720. I have tried BURR BROWN chips OPA627, OPA2134 etc with good results but so far nothing beats LME49720 except the Burson opamp. All opamps from the start of digital era were not made for audio applications.!!! Until a few years back and now like the LME opamp is strictly design for hi-end audio while the BURR BROWN opamp are not that’s what makes the difference. So if you buy an old CD put in the new generation opamp or caps or regs you will end up with a great sounding CD player. Too bad that hardware nowadays is not like it used to be.:music:
    Last edited: Apr 3, 2009
  9. PacificStereo

    PacificStereo Banned

    I seem to recall that the AD712 opamps were very good replacements for the ubiquitous duals (4558s, etc) and Sony used them interchangeably in many units. Fast, quiet and neutral. As you have discovered, gain/BW and slew performance is critical in those brick-wall filters, especially.

    Very cool that you've improved the 101- it was a pretty awful sounding player, but I remember when my first one came in... there were exactly 17 CD titles and wow, was that thing cool and magic!

    BTW, if you heat-sink those STKs (you have to jerry-rig something) you don't need a BX-1201.

    I wish I still had my 101 for nostalgic reasons. I do still have a CDP-400, which is essentially a 101 in a silver, standard box.
  10. Tinman

    Tinman AK Subscriber Subscriber

    Shoot.... I have 3 of them... where in So Cal do you live?
  11. mishak

    mishak New Member

    Hi Greg,

    I have old Sony CDP-200. I was told it is the same as 101, but I am not sure.
    Is it possible you send me a schematics, so I could try the same mods?

  12. Raddek

    Raddek Member

    I have an older CDP101 with the STK6922 chip and the player starts skipping after a while of playing. Does anyone know of a place that still sells these chips ? I've tried contacting a few sites on the internet but it seems they are all indefinitely out of stock :S
  13. Martin.Ca

    Martin.Ca Super Member

    That sounds like a tracking problem. You may need to clean and lube all the linear bearings.
  14. PacificStereo

    PacificStereo Banned

    Mmm... the STK-6922 is very often defective in these and is probably the leading cause of trouble in the 101/200/400/111 series. Very easy to tell- leave the player on for 15 minutes without doing anything. If it starts to make nasty clacking noises (this is the lens assy being bashed against the stops, never good!), the IC is defective. The STK6922 was replaced by an improved part, BX-1201.
  15. Martin.Ca

    Martin.Ca Super Member

  16. mishak

    mishak New Member

    thanks again for the manual.

    Another question: does anybody tried to add a digital output to this Sony 101 to be able to use it as a transport only? If yes, any link to schematics or suggestion where to plug it?


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