Speaker Relays

Discussion in 'Kenwood-Trio/Kensonic-Accuphase' started by JacTaylor, Apr 12, 2018.

  1. JacTaylor

    JacTaylor On the lam Subscriber

    Messages:
    14
    I'm not sure if this is a common problem but it seems to be with my limited exposure to 70s receivers. I purchased a Marantz 2252b and cleaned the heck out of the pots and I still had this requirement to increase the volume to prevent the fade out of one channel (right in this case). After searching a bit, I cleaned the speaker relay with small strips of business card paper/deoxit and that did the trick. This segue to the KR-9600.

    After restoring the power amps, power supplies/resistor mod and switch mod, I still had a similar problem with the Kenwood. At low volume, one channel just kind of fades out (again right channel). So I replaced both speaker relays with new ones and that again took care of the problem.

    I guess from reading, these relays after 40 years tend to wear out, too? Although, I've also read, they are one of the most reliable parts. At any rate, they're insidious in the way they creep into some of the problems that crop up.
     

     

    Please register to disable this ad.

  2. JacTaylor

    JacTaylor On the lam Subscriber

    Messages:
    14
    I understand, that makes sense...why a volume increase helps. These were about 30 bucks for the two with shipping. That's quite a bit cheaper!
     
  3. JacTaylor

    JacTaylor On the lam Subscriber

    Messages:
    14
    Just put an offer of 2.50 for 10 with 16 shipping...still about 4.2 each. Thanks!1
     
  4. JacTaylor

    JacTaylor On the lam Subscriber

    Messages:
    14
    Stated more than 10 available but I guess I bought him out.
     
  5. dr*audio

    dr*audio Fish fingers and custard!

    Messages:
    18,649
    Location:
    Cleveland, Ohio
    WRONG! NEVER use sandpaper on relay contacts! You remove the plating on the contacts that keeps them from oxidizing, and then they rapidly oxidize. Within a month that relay will be intermittent again. I learned this by painful experience, getting recalls on units I repaired. The contacts DO wear out, the plating gets worn and the contacts start to oxidize. There is a small amount of rubbing that takes place when the relay opens and closes that causes wear. Also a small amount of arcing from turn off transients in the amplifier. You can see the worn portions under a microscope. I also originally thought I could check if the relay was good by tapping on it to see if the channel dropped out. I missed a couple bad ones that way. No more! All speaker relays get replaced in older equipment.
     
    Goldie99 and johnlcnm like this.
  6. JacTaylor

    JacTaylor On the lam Subscriber

    Messages:
    14
    Thank you...good to know. Whether it's some deal on the Bay or known quality from DigiKey, small price to pay for perplexing problems due to old relays.
     

     

    Please register to disable this ad.

  7. dr*audio

    dr*audio Fish fingers and custard!

    Messages:
    18,649
    Location:
    Cleveland, Ohio
    I am not nitpicking and I am not going to argue with you. I have 40 years of experience professionally repairing this equipment. I can not allow something to leave my shop that might come back in a month with a problem. If the relay can't be replaced with one with the same footprint, I adapt the board so a modern replacement will fit. No excuses, no exceptions, no recalls. If shoddy work and cutting corners is good enough for you, that's your business.
     
    ovaeasy and spark1 like this.
  8. tarior

    tarior Dirty pool, old man? Subscriber

    Messages:
    6,503
    Location:
    Kelso, Washington
    Never use sandpaper. If you have a relay that is something special, clean the contacts with Flitz. If they don't come perfectly clean, no pits, no dark spots, with Flitz (or similar chemical product), then it must be replaced. Sandpaper, even 1000 grit or higher is bad juju.
    For me, the time it takes to desolder the relay, take it apart, clean it, inspect it, put back together, and solder it back in, I'm $ ahead just to slap in a brand new one.
     
    johnlcnm and dr*audio like this.

Share This Page