Upgrading the Creek CD60

Discussion in 'DIY Discussion' started by mjp200581, Apr 22, 2013.

  1. mjp200581

    mjp200581

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    Well it was inevitable really, after finally getting my hands on a Creek CD60 I'm now keen to see how good it can be after some upgrading.

    The Creek CD60 was a high end player from the early 90's. It features a Philips CDM 4/14 swing arm laser mechanism and a TDA1541A S1 (single crown) DAC chip. Like many players with the TDA1541 it also has the accompanying SAA7220 digital filter chip.

    The SAA7220 has dual role within the player. Firstly it performs the 4x oversampling and subsequent filtering of the digital data and secondly it also acts as the clock distribution device. Unfortunately the SAA7220 is a very noisy chip and injects a lot of noise (jitter) into the clock signal which it feeds to the other devices. Carrying out a NOS conversion and removing or bypassing the SAA7220 is therefore a relatively simple way of eliminating the problems associated with the noisy SAA7220 chip.

    A excellent explanation of the benefits of a NOS conversion can be seen here:

    http://www.net-audio.co.uk/tda1541nos.html

    Those of you who are familiar with this forum may have already seen my thread about upgrading an Arcam Alpha 5. A key move in the modification of my Alpha 5 was the conversion of the player to a non-oversampling mode by fitting a NET Audio Super non-oversampling kit. This kit is specifically developed for the Alpha 5 and involves removal of the SAA7220 digital filter chip.

    Of course by removing the SAA7220 you also loose the digital filter function it performs within the player. As a consequence unwanted sampling artefacts are not filtered out and remain in the audio signal and consequently are passed along to the rest of the equipment in your system. Advocates of non-oversampling argue that this is not a problem since this noise is at frequencies above the human hearing range and therefore doesn't adversely affect the sound.

    However other people believe that non-oversampling is a very bad idea and that the digital filtering function of the SAA7220 must be retained. A compelling argument for this is that whist this ultra sonic noise can't directly be heard by the human ear it most definitely is felt by the rest of the components in your system and consequently adversely effects the overall performance of the system. Back-to-back listening tests between the CD60 in standard form against the modified non-oversampling A5 show that whilst the Creek can't match the A5 for all-round listening pleasure it does do certain things in a superior way and this is what has spurred me on to see how good the CD60 can be made with a bit of tweaking.

    With my Creek CD60 I intend to carry out a series of upgrades whilst retaining the SAA7220 P/B chip and its 4x digital oversampling function. Hopefully I'll then be in a position to make some worthwhile listening comparisons between a well sorted non-oversampling player vs an equally well sorted player which retains oversampling.

    I'm going to try to be a little more focused in the upgrading than I was with the Alpha 5 project I intend to cover one topic at a time.

    I'd like to point out to anyone following this thread that the service manual/schematics for the Creek CD60 can be downloaded from the Creek website here:

    http://www.creekaudio.com/old-products/

    I hope you enjoy following my progress.
     
    mjp200581, Apr 22, 2013
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  2. mjp200581

    mjp200581

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    mjp200581, Apr 22, 2013
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  3. mjp200581

    mjp200581

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    O.K. the first topic of conversation is power supply capacitors.

    My CD60 is around 22 years old so I would imagine it's worth replacing the large electrolytic capacitors around the power supply.

    There are two pairs of capacitors:

    C61 and C86 are 1000uF 35v. These supply the 5 op-amps in the output and probably some other IC's around the display.

    C146 (3300uf) and C167 (1000uF). As far as I can make out these supply the DAC, filter chip, decoder chip and photo signal processor.

    As far as I understand long service life, low ESR and high ripple current handling are desirable here.

    I've selected some possible candidates:

    Panasonic FC:
    They seem to be very popular for PSU's and are probably a safe bet. Fidelity Audio use them in their CD60 upgrade package which is encouraging.

    Panasonic FM:
    These seem to be a higher spec alternative to FC. They have better service life.

    Nichicon KA:
    I don't can't find out much about these but they come in the correct dimensions and ratings for what I need and are marketed as premium components for audio.

    Rubycon ZLH:
    I used these before and so far they've been faultless. They have an excellent service life.

    With the three 1000uF capacitors there is the option to increase the capacitance value from 1000uF to 1500uF or even 1800uF without increasing the footprint on the PCB.

    Is increasing the capacitance rating a good idea? The higher value caps do tend to have a slightly lower ESR.

    Possible options for the large 3300uF cap are:

    Nichicon FW
    Nichicon KA
    Panasonic FC

    With the Nichicon KA it would be possible to go to 4700uF. With the FW's and Panasonic FC's I'd need to stick with 3300uF.

    Any advice as to whether or not swapping to higher capacitance values would be a good idea would be appreciated.

    Also does anyone have any specific recommendations on manufacturer and series?
     
    mjp200581, Apr 26, 2013
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  4. mjp200581

    pete693

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    Any advice as to whether or not swapping to higher capacitance values would be a good idea would be appreciated.


    The only thing that occurs to me is that larger capacitors present a larger load at switch-on until they become charged. This in turn means more drain on whatever is charging them and there might come a point where the source can't cope with such a near short circuit.
     
    pete693, Apr 26, 2013
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  5. mjp200581

    Tenson Moderator

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    Those increases in capacitance are rather small so I wouldn't worry about it causing problems. Just be aware that very low ESR can upset regulators.
     
    Tenson, Apr 26, 2013
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  6. mjp200581

    mjp200581

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    I heard that very low ESR can be problematic after regulators but does that also apply for capacitors before regulators?
     
    mjp200581, Apr 26, 2013
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  7. mjp200581

    pete693

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    If you Google "low esr problems" you will find lots of food for thought.
    Most of it goes way over my head but the general consensus seems to be that if low esr caps were not used by the original designer/manufacturer then adding them is likely to do more harm than good.
    It seems to be more of a problem with switch-mode power supplies that use supervisory chips but apparently can also cause problems in the signal path.
     
    pete693, Apr 26, 2013
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  8. mjp200581

    mjp200581

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    Yesterday I started work on the CD60.

    I cleaned the lenses on the laser inside and out (a nice advantage on the CDM4) and removed the power supply filter capacitors the output DC blocking capacitors ready for replacements. I also swapped the rectifier diodes for Schottky 11DQ10 types.

    But it wasn't easy! The PCB is double sided and through-plated and I found swapping out components to be very difficult. Even with my iron at it's hottest setting and armed with a flux pen, braid and a solder pump it was a struggle.

    Several years ago I remember struggling with a through plated PCB on a Cambridge Audio phono stage but I put that down to inexperience.

    It seems that through plated PCB's are a real pain to work on. Unless I can improve my de-soldering technique I may have to reconsider working on theCD60. It's too nice a CD player to mess about with and I don't want to risk damaging it.

    I'm inclined to put it the CD60 back together without any further modifications and to concentrate on my Arcam Alpha 5 which by comparison is a breeze to work on.

    Hmm.....time to take stock and reconsider.
     
    mjp200581, Apr 28, 2013
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  9. mjp200581

    pete693

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    De-soldering

    It's most important to apply fresh solder to the component you are removing prior to the actual removal.The new flux in the fresh solder will aid the flow of the old solder into the pump.Also do be careful with the iron temperature.Too hot and you will start to lift tracks.
    Pete.
     
    pete693, Apr 28, 2013
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  10. mjp200581

    mjp200581

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    Hi Pete,

    I remember reading that tip before somewhere on this forum. I did apply some new solder and also used the flux pen a bit but I obviously haven't got the hang of it. More practice needed.

    I've only ever had this difficulty on through plated PCB's, single sided ones seem very easy to work with.

    I picked up some top quality solder wick this morning. Hopefully that'll help next time.

    Anyway it's back together now and all is well. No damage done.

    While I was at it I couldn't resist swapping out the DC blocking caps at the output to some Elna Silmic II 100uF which I had in my spares pile.

    It does sound good. Those Silmics are very smooth.
     
    mjp200581, Apr 28, 2013
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  11. mjp200581

    RobHolt Moderator

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    Most definitely a good thing before regulators.
    It minimises ripple.
     
    RobHolt, Apr 28, 2013
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