Through with Buzz.


My turntable has just started creating an obnoxious buzz. Maybe you can help me fix it.

When I lift the arm, and the motor fires up, there is a loud buzz coming through the speakers. The sound stops at different times, but usually in the amount of time it takes for me to lower the needle to the record. Sometimes less time, sometimes more. When the record is over, and the arm is automatically lifted and dropped into the arm holder, the buzz comes back between when the arm is dropped and when the motor stops. If it weren't so loud, I wouldn't care, but man is it obnoxious.

I checked all connections, and they are secure.

Any ideas? Or should I just bring it to the shop?

The player is a Pioneer PL15d-II if that matters.

Thanks.

KB
karlrborne
THAT is a tough one. Is there a correlation with your physically touching the tonearm? If not, consider that there could be a ground wire perhaps in your tonearm that gets shorted out when the tonearm lifts off the LP. Look for a loose wire.
Thanks Lewm, I'll check it out. There is no correlation to me touching the tone arm.

KB
Sounds like a wire is damaged inside the arm or the arm wiring harness at the very least. As the arm is moved, the buzz comes and goes. So it would be the wire that grounds the arm (black wire) that is having the problem.
Is it a buzz or a hum? They are completely different things, a buzz is a BBZZZ and a hum is HHMMMM.
Is there a dimmer switch on the same circuit? That was causing my intermittent buzz problem. If the TT has muting, the buzz will stop while the arm is moving.
Thanks for the feedback. This is most certainly a buzz and not a hum. When the buzz stops, quickly after the needle touches the record, it usually is gone for good. Very, very rarely it buzzes for a split second during play, then disappears. But that makes me nervous to play anything too loud.

Due to my lack of understanding of how these turntable operate, I think I'll bring it in for a fix so I can get back to tearing into some Steely Dan, among others. My current favorite song to play on the turn table is actually a Robert Palmer song, "Every Kinda People." Love it.

I'm not sure if there is a dimmer switch. But I think Atmasphere is on to something.

Again, thanks.
I took a look at the service manual for the presumably similar PL-15D, which can be downloaded by registering at vinylengine.com.

My suspicion is that the problem is being caused by a combination of the switch that controls application of AC power to the motor, and a capacitor (described as 0.047 uf with a voltage rating of 200 VAC) that is wired directly across the switch. I believe that the purpose of the capacitor is to suppress RFI (radio frequency interference) that may be generated as the switch opens and closes.

According to another reference I have, the PL-15D II dates back to the 1970's. It would therefore stand to reason that both the switch contacts and the capacitor are somewhat degraded. Abnormal amounts of RFI could therefore be generated by arcing resulting from "contact bounce" in the switch, which may in turn not be effectively suppressed by the old capacitor.

It would probably be a good idea to mention that possibility to the person at the shop you take it to.

Regards,
-- Al
I tried to watch and listen intently to the problem tonight, and at the end of the third record, it stopped spinning altogether. Maybe the motor is shot. Off to the repair man tomorrow.
The incredible Bob Babbitt of The Funk Brothers on every Kind of People with that amazing bass line...what a musician.