CR-2040 : recap experiences ?

Discussion in 'Yamaha' started by master_fo, May 18, 2018.

  1. master_fo

    master_fo New Member

    Messages:
    7
    I am tempted to recap at least the phono stage of CR2040 - there seem to be lot of caps in the signal path. When I recapped my KEF Cantata speakers, all caps were off by at least 15%, and smallest were off up to 300%.
    CR-2040 probably runs hotter than the speaker crossover, so I would definitely expect some drift here. Since this is the only place in the receivers's signal path where caps are actually forming frequency responce, I am definitely inclined to check.
    @merrylander was quite vocal about his CR-2040 experience in other threads - yet that was 10+ years ago and 25 yo vs 40 yo caps could make a difference.
    Did anyone measure the caps taken out of CRxxxx?
    If I hear that all caps there were within 10-15%, I would surely hold my horses.
    If it did make a difference, please share your recap lists!
     

     

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  2. mbz

    mbz AK Subscriber Subscriber

    Messages:
    1,946
    Location:
    Melbourne, Victoria
    I'd recap the power supply first, the caps take a hammering and more likely to be stressed unlike the audio path. Whether main filters etc... affect the sound
    quality is up for debate, however I recognize that most of the watts come from the unregulated supply ie, directly from the main filters->output transistors->spkr.
    To be honest, I'd recap the whole thing but ok to take the cautious approach.

    Couldn't find @merrylander thread, my general guidelines are,
    Main filters: UCC SMH or KMH series, others prefer Nichicon KG
    Rest of psu: Nichicon PW
    Bipolar(psu): Nichicon EP
    Bipolar(audio): Nichicon ES
    Low noise(phono stage): Nichicon UKL (some prefer wima MKS2)
    General audio: Elna Silmic II's
    Local power rails: Elna Silmic II's

    I'd also replace bias trimmers with multiturn types, also spkr relay and ...

    No experiance with 2040, recapped CA-800/-1000/-1010/-2010 and a few others
     
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  3. zaibatsu

    zaibatsu Well-Known Member

    Messages:
    592
    I presume the service manual linked here has a parts list, you can use it to list all the electrolytic capacitors yourself:
    https://www.hifiengine.com/manual_library/yamaha/cr-2040.shtml
    You can sign up for a free account to download from there.
    It's wise to double check the parts in the amp as sometimes the manuals have mistakes, but usually pretty close.

    You'll probably get more out of the whole process if you make your own list, and you can post it here for critique before ordering.
    I'd highly recommend building a dim bulb tester so you don't blow up your amp from simple mistake/s, especially if this is your first go.

    mbz's recommendations are great, personally I'd skip the Elna caps (muddy sound during long break-in = pain) and just use UCC/Nichicon for the lot.
    FYI, capacitance isn't the only way in which electrolytics degrade. Just work slow and set up the precautions before first start-up if proceeding.

    Welcome to AK!
     
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  4. Bratwurst7s

    Bratwurst7s In The Frying Pan Subscriber

    Messages:
    4,001
    Location:
    Munich, Germany
    No experience with this particular amp but in general...

    Second the recommendation for UCC KMH, I've been using them and like them a lot.
    I've been tending towards Nichicon KL, KZ and ES (bi-polar) in the signal path except for 10µF and smaller where I use Wima MKS2 film caps.
    Elsewhere for local filtering I've been using Panasonic FC and FM. They usually have a higher ripple rating and longer rated lifespan than most others. and are 105° rated.
    PSU I've been using UCC KYB and Panasonic FM & FC. Again for the above reasons.
    Anything under 10µF anywhere in the amp where they fit (measure for size!!!) Wima MKS2 film.

    Cheers and welcome to AK,
    James
     
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  5. master_fo

    master_fo New Member

    Messages:
    7
    Thanks @mbz! Great list.
     
  6. master_fo

    master_fo New Member

    Messages:
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