Yamaha cr-2020 repair and restoration

Discussion in 'Yamaha' started by rcaman, Jul 17, 2017.

  1. Bert 1100

    Bert 1100 Super Member

    Messages:
    1,060
    Location:
    Planquiri !
    @Oilmaster , another question if I may :biggrin:

    On the phono board (I think it's the phono part, at the back of the tuner board...) There are 8 tantalum caps (4x 220uf / 6.3V and 4x33uf / 10v)
    Should I change them for new tantalums (TAP227K006CCS by AVX) or change for new electrolytics ? Or should I leave them alone ?

    Thank you !
     
  2. avionic

    avionic " Black Knights " Subscriber

    Messages:
    36,813
    Location:
    Fort Dodge, Iowa
    Electrolytics.
     
  3. avionic

    avionic " Black Knights " Subscriber

    Messages:
    36,813
    Location:
    Fort Dodge, Iowa
  4. Bert 1100

    Bert 1100 Super Member

    Messages:
    1,060
    Location:
    Planquiri !
    Thanks Avionic !
     
  5. Oilmaster

    Oilmaster Ozzy Subscriber

    Messages:
    1,074
    Location:
    Paris & The Hague
    yep
    Given the highly densely populated area, options are very limited.
    If space and lead spacing allowed for it, I would use Nichicon KZ or FG, but here there is simply too little space
    In fact, after a lot of doubting, I decided to leave the tantalums in, probably regretting it sooner or later....But the married couple receiving this CR-2020 probably won't ever use it, so.....
     
  6. avionic

    avionic " Black Knights " Subscriber

    Messages:
    36,813
    Location:
    Fort Dodge, Iowa
    That is why I go with the miniature MW/SW series Nichicon.
     
  7. Mr. Yamaha

    Mr. Yamaha Not so much Yamaha lately... Subscriber

    Messages:
    604
    Location:
    Amsterdam Area, The Netherlands
    Why not new tantalums?
     
  8. Bert 1100

    Bert 1100 Super Member

    Messages:
    1,060
    Location:
    Planquiri !
    I was wondering as well, basically the question is : why did Yamaha choose tantalums in the first place ? what makes them superior to electrolytics ? Or was it pure economics, because they were cheaper ?
     
  9. Mr. Yamaha

    Mr. Yamaha Not so much Yamaha lately... Subscriber

    Messages:
    604
    Location:
    Amsterdam Area, The Netherlands
    Maybe because there was no room for electrolytics which were available back then (value and size) or because their (sonic) performance. If it's the first reason and there are electrolytics which are small enough, that would be fine I guess.
     
  10. rottalpha

    rottalpha Yamaholic

    Messages:
    1,175
    Location:
    Middle of Crook County
    Or maybe back then the high failure rate of tantalum caps was not yet known.
    Inherently, the tantalum caps have lower ESR than their electrolytic counterparts. They also have a size advantage, but they also tend to fail faster.
    There are a few papers published on the subject.
     
  11. Oilmaster

    Oilmaster Ozzy Subscriber

    Messages:
    1,074
    Location:
    Paris & The Hague
    I guess a mix of all the above.
    Being a fact that they were the most expensive choice for Yamaha, they must have believed they were the best option, and given the state of other caps at that moment, they may have been for both MM and MC service (the latter being sensitive to leakage and noise from 70's lytics). In the vinyl heydays, a well performing RIAA section was important for high-budget gear. With a MRSP of $750, which would be around $2750 in today's value, they had to throw in some quality parts. Nowadays we have electrolytic caps that can perform as good or better.
     
  12. fernarias

    fernarias AK Subscriber Subscriber

    Messages:
    859
    Location:
    Merced, CA
    I wouldn't say tants have a high failure rate since these have lasted 40+ years and some have outlasted the other components known to fail in a 2020 (actually haven't seen a tant fail in a 2020). When they do fail they tend to short or leak. Modern tants are very reliable and would work well in the phono section of the 2020. I'm surprised no one has replaced vintage tants with modern tants and just used the recommended voltage requirements for modern tants.
     
    Last edited: Sep 14, 2017
  13. rottalpha

    rottalpha Yamaholic

    Messages:
    1,175
    Location:
    Middle of Crook County
    I have replaced old with modern tents...but not for critical functions. Replaced in vu-meter sections of the B-2 as an example....
    Found a bunch inside the C-1 and as you mentioned...they have been working for a long time....but none will be replaced with tantals, modern or otherwise.....I will not take the risk if I don not have to. Modern lytics have gotten so good..I can get small size caps these days with 10-20k hours ratings.
     
  14. Bert 1100

    Bert 1100 Super Member

    Messages:
    1,060
    Location:
    Planquiri !
    I ordered these and installed them and all is working fine, but just as information, the 220uf/6.3V is actually 8mm diam. by 5mm length, Mouser has the 2 values swapped.
    And 8mm in diameter is a bit too much in the cramped space of the phono pre, you need to leave the legs a bit longer and play with the positioning.
    So it would have been better to order both the 220uf and the 33uf in the USW series. The 220uf in UMW is fatter at 8mm, in the USW series it is 6.3mm in diameter and will fit much more easily.
     

Share This Page