Sansui 6060 Help crackle and static

Discussion in 'Exclusively Sansui' started by tweedsmith, Mar 14, 2017.

  1. tweedsmith

    tweedsmith New Member

    Messages:
    15
    Hello,
    Would anyone(s) be willing or able to assist me with repair on my beloved Sansui 6060? I am pretty good with a soldering iron, and used to repair Panasonic digital broadcast equipment for productions studios and TV stations. I'm a little rusty at troubleshooting and component recognition. I'd like to keep this one running. A local shop gave me an estimate of $350-$400 if all it requires is a recap, and money is tight at the moment. I checked around the forum at various times for this issue, but i think i need more specific personalized help.

    My receiver has a few little problems and one big one.

    Everything turns on and i can play my turntable and use the aux in for streaming over Airplay.

    The main issue is occasionally there is a loud cracking in the left channel, very sharp and loud. bad for my speakers and ears and waking/scaring the baby! (i want her to love music, not be afraid of the stereo!) this is usually accompanied by loud static, and sometimes loss of signal in the left channel for a period of time.
    Sometimes it occurs at startup, and other times it plays fine (for days at a time) and comes out of nowhere. not related to turning knobs or anything. I can have the volume all the way down and it still occurs. Turning the speaker selection to off will stop it, but no other input or knob settings change anything

    There is also a constant kind of flap flap flap, that is not very noticeable when music is playing. that's not a dealbreaker, but i'd like to clear it up if possible while i'm in there (caps?).

    I'm going to attempt to attach a file but i could only get the flap flapping, I didn't catch the crackle.

    I have a schematic and manual downloaded, and I'm good at admitting I don't now something.
    I've attached some internal pictures here.

    Any help would be appreciated!

    IMG_1217.JPG IMG_1218.JPG IMG_1214.JPG IMG_1212.JPG IMG_1216.JPG IMG_1213.JPG IMG_1215.JPG IMG_1219.JPG
     
  2. Leestereo

    Leestereo Super Member

    Messages:
    1,830
    Location:
    Ottawa, ON
    Input differential transistor pair (2SA726s) on the power amplifier driver (vertical) board should be replaced with a hFE matched pair (e.g., KSA992). I suggest that the differential pairs in both channels be done when the driver board is out.
     
  3. bberkom

    bberkom AK Subscriber Subscriber

    Messages:
    591
    Location:
    Nashville, TN
    You can also download the service manual below to help in your restoration. You have to sign up, but it's free! A good cleaning and recap is probably due even if replacing the transistors suggested previously fixes your specific problem for now.

    https://www.hifiengine.com/manual_library/sansui/6060.shtml
     
  4. tweedsmith

    tweedsmith New Member

    Messages:
    15
    ok thanks. these?

    3-14-2017 12-58-09 PM.png
     
  5. Leestereo

    Leestereo Super Member

    Messages:
    1,830
    Location:
    Ottawa, ON
    Yes, those are the ones. The 2SA726 are known to fail as they age, in particular the ones with the BCE pinout (the KSA992 replacements have an ECB pinout and are installed facing 180° away from original orientation).
     
  6. tweedsmith

    tweedsmith New Member

    Messages:
    15
  7. tweedsmith

    tweedsmith New Member

    Messages:
    15
    Ok
    ok thanks! i do have a service manual downloaded for reference.
     
  8. Leestereo

    Leestereo Super Member

    Messages:
    1,830
    Location:
    Ottawa, ON
    Yes, those are the correct transistors; order ~10 to ensure you can get hFE matched pairs.

    IMO, if you want the best possible sound from your 6060, the ~40 year old capacitors should definitely be replaced/upgraded. The small signal path capacitors (e.g., C01/C02, C03/C04, C05/C06) can be upgraded to stacked film types or bipolar types. The non-signal path capacitors can be replaced with low ESR types. Although not specifically for your 6060, this Sansui restoration thread can give you an idea of what is possible:
    Restoration/Upgrade Of Scribby31's Sansui AU-9500
     
  9. tweedsmith

    tweedsmith New Member

    Messages:
    15
    Ok, thanks. I'll check out that thread. I may need some help identifying what parts to order and replace with what, for the caps. I don't see them listed in the parts list for that board. ...and how to hFE match.
     
  10. tweedsmith

    tweedsmith New Member

    Messages:
    15
    i'm going to try to get into this tonight. I'll see if i can get a parts list together.
     
  11. Oldsansui441

    Oldsansui441 AK Subscriber Subscriber

    Messages:
    803
    Location:
    Victoria, Australia
    As Leestereo suggested it sounds like you have transistor problems. These are also renowned for the fusible resistors on the main amp and the power supply to drift in value or even go open, l had one a while back that l went through.

    All the best with it.
     
  12. tweedsmith

    tweedsmith New Member

    Messages:
    15
    Ok, so, I may need assistance getting a parts list together. I have the values off the caps, but I'm not sure if I can find what to order on Mouser on my own. I'd rather go ahead and order the Caps while I'm replacing the transistors.


    The parts list doesn't show the capacitors for this board. I'm wondering if they are listed in this missing "attached" page referenced below? Anyone happen to have that info? It was not included in the manual I downloaded.



    3-16-2017 4-31-18 PM.png

    3-16-2017 3-12-39 PM.png
     
  13. LBPete

    LBPete Rolling Along Subscriber

    Messages:
    10,249
    Location:
    Long Beach, CA
    Don't rely on the service manual to ID replacement parts. Sansui is famous for making undocumented running changes. Take an inventory of the actual parts on the board to be safe. The 6060 and 5050 had a major revision during production. You have the early version that matches the service manual. The later version is not well documented.

    Please post the serial number for the database.

    - Pete
     
    Godi likes this.
  14. tweedsmith

    tweedsmith New Member

    Messages:
    15
    The serial number for my 6060 is 026090728.
    I'll post my order later for reference.
     
  15. tweedsmith

    tweedsmith New Member

    Messages:
    15
    Here's my order for reference. I doubled the Capacitors and got 10 transistors as suggested.
    If anyone sees any discrepancies or issues, I'd appreciate the feedback.

    3-17-2017 5-26-27 PM.png


    Here are some shots of the board removed as well. Parts should be in Tuesday!


    File_000 (8).jpeg File_001.jpeg
     
  16. Hyperion

    Hyperion Roobarb & Custard Subscriber

    Messages:
    36,339
    Location:
    Hertfordshire, UK
    Your trimmers should be Mouser P/No 652-3386X-1-102LF I would be surprised if the ones you have ordered will allow you to adjust them when mounted. The pictures on the Mouser website for these Bourns trimmers are generic - and do not necessarily reflect the individual part - beware.

    http://www.mouser.co.uk/ProductDetail/Bourns/3386X-1-102LF/?qs=sGAEpiMZZMvygUB3GLcD7rufck0TIBKyhWELQMLXPQg=

    Also why "Organic Polymer" for item number 2 on your list ?

    Better
    http://www.mouser.co.uk/ProductDetail/Panasonic/EEU-FC1C221/?qs=sGAEpiMZZMvwFf0viD3Y3ZokEWucPCYoqQWsHiZXZCw=

    Mouser P/No 667-EEU-FC1C221

    :thumbsup:
     
  17. tweedsmith

    tweedsmith New Member

    Messages:
    15
    Ok thanks!
    For the VR I was just going off leestereo's sansui thread and trying to guess based on the info there.
    I'm not sure why/how I chose that organic polymer cap. I'll have to see what comes in.
    I'm hoping the transistors fix the original issue. Was just hoping to recap in one shot while in there.
     
  18. Oldsansui441

    Oldsansui441 AK Subscriber Subscriber

    Messages:
    803
    Location:
    Victoria, Australia
    Hyperion likes this.
  19. tweedsmith

    tweedsmith New Member

    Messages:
    15
    thanks for the assistance everyone! My order should come in today. I was hoping to recap while the board is out, but i think i'll see if the transistors fix my main issue, and then make another order based on the information in this thread to do the recap.
     
  20. Oldsansui441

    Oldsansui441 AK Subscriber Subscriber

    Messages:
    803
    Location:
    Victoria, Australia
    At least those boards are easy to remove and refit especially with the harness connector, wish they were all like that :).
     

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