Hum when I hook cables into the phono - nothing else hooked up.

Discussion in 'Pioneer Audio' started by TMaster, Jan 8, 2019.

  1. TMaster

    TMaster New Member

    Messages:
    20
    I have tried 4 receivers (SX-3800, 949, 880, 680) and two sets of cables, All the receivers hum when I plug the RCA cables into the back into the phono (nothing else hooked to the other side). One set is a monster 6' gold connector version, the other is a 3' cheapy. The hum goes up with the volume. I have cleaned all the connectors very well also with Deoxit. The turn table works fine with my fathers new Sony with AUX, and a phono preamp box. Now, when I plug the cables into the AUX on the vintage receivers, there is no hum, but once I hook the phono preamp box into the aux the hum comes back! I am really stumped here. All the vintage receivers can't be bad... Yes I have tried the ground wire both tests and it barely helps the hum. I'm not sure what to do next, thanks.
     

     

    Please register to disable this ad.

  2. larryderouin

    larryderouin Turn it UP, POP? PLLUUEEEZZZZZEE Subscriber

    Messages:
    22,014
    Location:
    Glen Burnie Md.
    What is the turntable, and the Cartridge? Some combinations (there are more than a few) hum like a whore in Church, no matter what you do to them at the interconnects. You may have a broken ground somewhere between the Terminal Strip at the RCA Jacks, and the Cartridge connections. Best bets are in the Tonearm itself, and underneath btwn the tonearm and the "T" STRIP.
     
  3. TMaster

    TMaster New Member

    Messages:
    20
    Pioneer PL-55DX and it works with my fathers setup. I let him borrow it to test, and then after he brought it back today. I checked the continuity before I let him test it, and there was a good ground between the arm and chassis.
     
  4. F1nut

    F1nut Super Member

    Messages:
    1,932
    Location:
    The Mars Hotel
    Your vintage receivers have two prong power cords, which means there is no earth ground only a chassis ground. Try running an additional ground from the table to a known earth ground, perhaps the screw on an outlet cover.
     
  5. TMaster

    TMaster New Member

    Messages:
    20
    The extra ground into the ground on the AC outlet didn't make a difference. The Turntable is crazy sensitive. I just was brushing a non connected wire across a chassis screw and fuzz sound would come out the speakers. haha. So I tried a different receiver last night mid 80's Kenwood, and it hummed also. The only thing different was my dads brand new Sony receiver and different cables and it was perfectly clear (using the PL-55DX). So I am going to bring his stuff over here and test it out. Also he has a modern turn table I can try on these receivers. I will report back when I can get some results. One stupid question, is it normal for these receivers to have a feedback hum when just plugging cables into the Phono with noting else hooked to the other end?
     
  6. Wolfman181

    Wolfman181 Active Member

    Messages:
    132
    Hello. This may sound weird but try this. I have vintage stuff and had the same issues. Try hooking things up and turn down the bass a bit or alot. Or turn off the loudness on the receiver at the same time. On the vintage receivers and if you have vintage speakers as well you can get feedback from to much bass response. Give it a try and see if it reduces or go away. Good luck.
     

     

    Please register to disable this ad.

  7. TMaster

    TMaster New Member

    Messages:
    20
    Ok, I resolved the issue! It was a faulty ground wire from the turn table to the receiver. The wire was very old and not making a good connection. I should have continuity checked it beforehand with my Fluke!!! I must have spent 6 hours or more on this problem. I even ordered caps, and diodes for the turntable board. haha! My Father came over today with his equipment, and his own ground wire. That's when we found out. Thanks for the help everyone. Some good info here for anyone with this problem.
     
    dlucy likes this.
  8. Wolfman181

    Wolfman181 Active Member

    Messages:
    132

Share This Page