Nakamichi CDP2 cdplayer

Discussion in 'DIY Discussion' started by Marked, May 28, 2015.

  1. Marked

    mjp200581

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    Near the RCA output there are usually two small caps something like 22nF, either ceramic or sometimes film. These decouple high frequency noise to ground. Do not remove them, they are there for a reason! The Lampizator website is great fun but some of the ideas on there are a little crazy.
     
    mjp200581, Jun 2, 2015
    #21
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    Marked

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    This is what I meant, the two (three when include headphone) capacitors connect rca shield to chassis. They are never connected to signal. nak7.jpg
     
    Marked, Jun 2, 2015
    #22
  3. Marked

    mjp200581

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    Yes I would just leave those, they need no attention. They shunt high frequency noise to ground, that's all.

    If I'm following the PCB correctly C229 looks like it is the DC blocking coupling capacitor for the output. These are the ones which you are upgrading to to the Wima film?
     
    mjp200581, Jun 2, 2015
    #23
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    Marked

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    Yes 229&230 are the dc blocking caps for which I ordered the 10uF Wima's. But will measure DC first to see if it really has a function, I also ordered some opamps, so trying to figure out how these are connected now, some have higher bandwith LOL But first I will only replace some electrolytics and have a listen. Then probably step by step the electrolytics for servo etc because I really fear changing operation in that part, all cd's load real fast, much faster than on other cdplayers I have, there is no audible jumping or skipping a beat on scratches where my other players do, so that part of this cdplayer is functioning very very well, hate to introduce some degradation there.

    I think lampizator saw filmcapacitors near rca output and because not ceramic he assumed they were in signalpath ???
     
    Marked, Jun 2, 2015
    #24
  5. Marked

    mjp200581

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    Well as I understand it the purpose of these caps is to pass very high frequency noise on the output to ground. In my thinking any frequencies which these caps remove is ultrasonic noise 'pollution' well above the audible frequency range. I suppose it is possible that removing them changes the sound but I'm more inclined to side with all of the major audio companies that fit them than one guy on the internet. Remember everyone on the internet is an 'expert'.

    I doubt you have any trouble replacing the caps around the servo, you can only make things better.

    I really like the LM4562 op-amps in my Sony. I still haven't tried the OPA2604.
     
    mjp200581, Jun 2, 2015
    #25
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    Marked

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    Again the filmcaps only connect output gnd/rca shield to chassis, they are nowhere connected to signal output. So yes they could influence gnd and throught gnd sound.
     
    Marked, Jun 2, 2015
    #26
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    Marked

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    Uninteresting pic, funny enough capacitance all 4 2200uF's is about the same just above 2700uF. ESR (or impedance) of two on the left, the dirty rubber ones is about twice that of the clean rubber ones on the right, but not very high, around 50 mohm or 0.05 ohm.
    Nak8.JPG
     
    Marked, Jun 2, 2015
    #27
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    Marked

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    Replaced the four 2200uF for 5600uF Panasonic FC, the rectifier/diodes befor that for Schottky Vishay SB1H100. After regulators first two 470uF's are replaced for 1000uF's SilmicII. After the later 5V regulators the two 220uF's are also replaced for SilmicII 470uF. Opamps still the original Signetics 5532 but I already put them in sockets.
    In other powersupply lines all first electrolytics are replaced for Panasonic FC, equal values to what were there originally. I will let cdplayer play some time befor doing other things that could improve sound, in meantime in steps I will replace the other small electrolytics, I think I ordered Nichicon PW for all of them, equal values to the ones on the pcb now mostly if not all? Will make some photo's next time to show how normal this looks inside sofar:)
     
    Marked, Jun 4, 2015
    #28
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    mjp200581

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    How does it sound?
     
    mjp200581, Jun 4, 2015
    #29
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    Marked

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    server error last night it appears
    Player has been playing 8 hours yesterday, some areas showed some changes in these 8 hours.
    Dynamics, slam, bass power and detail improved a lot, treble detail, openness, clarity too. Initially yesterday the male vocals and piano sounded a bit restrained, held back, slow, all descriptions I try in this foreign language are a bit too big, but hope you get the idea:) That really changed to inaudible or almost inaudible after 8 hours. I will try to hear that again today, but could be something chemical inside capacitors that solved it. I haven't been listening full 8 hours, just let it play and sometimes sit down in that room to listen. Late last night the listening got me real quiet, really above expectations. I still have bag of parts I want to use/try, but now it sounds real nice. Will compare to other cdplayer for reference later.
     
    Marked, Jun 5, 2015
    #30
  11. Marked

    mjp200581

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    That's a great start. It'll be interesting to see how it sounds with an op-amp upgrade.
     
    mjp200581, Jun 5, 2015
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    Marked

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    Well replaced 6 other ecaps, this picture is from just befor that, it does show opamps switching will be easy now
    nak9.JPG
     
    Marked, Jun 5, 2015
    #32
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    mjp200581

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    Nice job.

    I suggest you get familiar with player for a while and then try some different op-amps.

    After that I've got plenty of other upgrade ideas for you.
     
    mjp200581, Jun 6, 2015
    #33
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    Marked

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    Replacing 0.47/1/4.7 and 4 10uF's made a difference in treble, replaced caps all measure well within 20%, ESR for all of them above 2 ohm, higher frequency capacity for the little ones 0.0000uF, Nichicon PW's used ESR all close to 1 ohm, all have capacity at higher frequencies. Well these shouldn't have made an audible difference I thought. Fortunately tracking/focus error correction still perfect:) Maybe last ten of the tiny ecaps tonight...
     
    Marked, Jun 6, 2015
    #34
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    Marked

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    Finished replacing all electrolytics, sofar no problems noticed with worse cd reading :)
    Tried to draw from dac output touching deemphasis Jfet through dual opamp to finally dc blocking electrolytic, didn't help me yet :)
    nak11.png
     
    Marked, Jun 6, 2015
    #35
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    Marked

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    OK Wima 10uF's replaced the electrolytic Chemicon 47uF dcblocking/coupling output capacitors, detail bass/mid/treble improved again, bad recordings do sound worse, meaning the electrolytics do make signal a little kind/sweeter in top end, which probably costs detail too, for instance recorded noisefloor is more audible with Wimas. Bass strenght didn't suffer, infact it seems more powerfull, more controlled though. Imaging, coming free of speakers, is improved a lot. Wider deeper higher more focussed, the lot.
    The cdplayer still smells nice of leaking electolytics, remove the cabinet top or open cdtray after playing few hours and that nice smell comes out :) So it probably means when player would have been in topshape all of this would have been much harder to describe as plusses, improvements all the time. Next I will replace the decoupling caps directly next to tda1541 for SMD PPS exept for MSB, that will become 1uF Wima, like latest Phillips instructions.
     
    Marked, Jun 11, 2015
    #36
  17. Marked

    mjp200581

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    Your listening impressions match my own experience very closely.

    The PPS SMD caps are excellent but I would put them down the priority list a little. I used Panasonic 0.1uF all all but the MSB pins 1913/4833 size works well (Farnell code 2326069).

    Read my Arcam thread for details about adding a 10uF to 15uF Oscon from -5v to -15v on the TDA.
     
    mjp200581, Jun 11, 2015
    #37
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    mjp200581

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    The Panasonic part number is ECH-U1H104GX9

    Just check that they will fit your PCB OK.
     
    mjp200581, Jun 11, 2015
    #38
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    Marked

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    Yes I have plenty of those :) I didn't look at Oscons, but I have some I may use, don't know. Will read what -5 to -15 is all about
     
    Marked, Jun 11, 2015
    #39
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    Marked

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    They told us this pub was very cozy, just one sitting here with us and he feels he is better than us :(
    lonely.JPG

    There is a party in the basement :)
    hello.JPG
     
    Marked, Jun 12, 2015
    #40
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