Where purchase circuit breaker for Sunn Concert?

Discussion in 'Amps and Cabs [BG]' started by sunn bass, May 24, 2020.

  1. sunn bass

    sunn bass

    May 24, 2020
    Anyone know where I can purchase a replacement circuit breaker for a 1972 Sunn Concert Bass amp? Thank you in advance.
  2. seamonkey


    Aug 6, 2004
    Not much info on the schematic
    Elektrotanya for electronics experts
    But it should be marked with a rating.

    If the breaker pushes in, but keeps popping then there may be a legitimate reason why, like something is wrong with the amp.
  3. sunn bass

    sunn bass

    May 24, 2020
    Thanks Seamonkey. I'll take a look again to see if I can find a rating on the circuit breaker. I didn't see one easily when I was looking yesterday, but it may be further under it.

    The red circuit breaker "switch" /button is one of those that pushes straight in. Or seems its supposed to push straight in. But this one seems to be frozen so it kind of moves a little but doesn't push way in like it would seem it needs to. Seems like its stuck out.

    If I can find a rating on the switch, do you know where I can purchase a new circuit breaker?

    Thank you.
  4. seamonkey


    Aug 6, 2004
    Digikey or Mouser would probably have one
  5. sunn bass

    sunn bass

    May 24, 2020
    Thanks again Seamonkey. I'll check em out.
  6. BassmanPaul

    BassmanPaul Inactive

    In the worst case you may have to replace the breaker with a fuse holder and a fuse of the correct value.
  7. Wasnex


    Dec 25, 2011
  8. BassmanPaul

    BassmanPaul Inactive

    Remember that the new breaker has to have the same current rating as the existing one.
    Wasnex likes this.
  9. Wasnex


    Dec 25, 2011
    And hopefully fit in the same hole ;).
    BassmanPaul and agedhorse like this.
  10. sunn bass

    sunn bass

    May 24, 2020
    Very helpful replies everyone. Much appreciated. I'm going to work on this more today and see how far I get with it. Thank you.
  11. Michedelic

    Michedelic MId-Century Modern

  12. Passinwind

    Passinwind I know nothing. Commercial User

    Dec 3, 2003
    Columbia River Gorge, WA.
    Owner/Designer &Toaster Tech Passinwind Electronics
    Did you check at these two Sunn forums?


    The sunn Forum - Index
  13. beans-on-toast

    beans-on-toast Supporting Member

    Aug 7, 2008
    Here is a copy of the schematic and circuit updates. The circuit breaker is rated 3A, 4.5A surge. There should be some identifying marks on the case. Some have a number on the button indicating the amperage. The replacement has to fit, both against the panel and in depth, check the dimensions before ordering a replacement.

    Attached Files:

    seamonkey, BassmanPaul and Wasnex like this.
  14. daveman50

    daveman50 Supporting Member

    Feb 24, 2007
    Albany NY
    That's what it says on the back of my 1972 Concert Bass amp.
    beans-on-toast likes this.
  15. You might be able to remove the breaker, open it up and clean it with some CRC. It might just be stuck from years of non-use. I traded a pair of stereo speakers to a guy for a sweet little Stromberg-Carlson tube amp that wouldn't power on due to a stuck breaker. I cleaned it, put it back in and now I have a fantastic sounding low power stereo amp. Couldn't hurt to take a look at the breaker.

    Rick B.
    Garret Graves likes this.
  16. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa, Product Support-Genz Benz
    I believe those breakers are sealed. (I.e. won't come apart without breaking.

    In general with breakers, replacement is the safest approach. As an alternative, replacement with the same value fuse and a new fuse holder will work if you can find a fuse holder that fits the hole. There used to be some but I don't know if they are still made.
    BassmanPaul likes this.
  17. sunn bass

    sunn bass

    May 24, 2020
    I checked around a bit on the various links sent, but Im not really good at figuring that all out. I didn't see a clear number on the circuit breaker so wasn't sure I would be able to identify a replacement. So I clipped the wires, took it out, gently opened it up, sprayed the internal parts with DeOxit, got the frozen part moving nicely again, and then gently put it back together, installed and soldered the wires back on, and...to my surprise, it worked! Thank you again to you all, as I appreciate the info very much and am grateful for such kind folk out there willing to assist.
    seamonkey likes this.
  18. agedhorse

    agedhorse Supporting Member Commercial User

    Feb 12, 2006
    Davis, CA (USA)
    Development Engineer-Mesa, Product Support-Genz Benz
    Do not use it that way, it's essential that in the event of a fault it opens to protect against fire. It needs to be replaced, all new parts carry UL recognition for a safety related part.
    BassmanPaul and Geri O like this.
  19. Primary

    Primary TB Assistant

    Here are some related products that TB members are talking about. Clicking on a product will take you to TB’s partner, Primary, where you can find links to TB discussions about these products.

    Jun 13, 2021

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