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Loud hum from speakers while in phono - what am I doing wrong?

SCAPE_GOAT

SCAPE_GOAT

New Member
I’m experiencing loud, bass-y hum from my speakers when turned to phono on my receiver, even with the volume low. It’s an old Pioneer PL-15D II turntable. I’m trying to figure out what’s going on. I’ve got everything hooked up correctly, but the GND post on my receiver (an SX- 580) is rusty. The GND connector prongs on the cord itself are also a bit bent. Could these things be a problem? Is it the RCA cord as a whole? I’ve noticed from moving the cord around that the hum kinda goes in and out, but no matter what I do, it’s persistent and overwhelming. Do I just have an overall bad connection? Is this a problem with my receiver or my turntable? Any advice helps. Thanks in advance.
 
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How close are your speakers to the turntable and what are things sitting on? You might be getting acoustic feedback.
 
Montycat said:
How close are your speakers to the turntable and what are things sitting on? You might be getting acoustic feedback.
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At first I had the turntable and speakers very close (on the same table) just to test it out, but then moved the turntable away to make sure that's not what the problem was. The hum persisted after separating the speakers and turntable. I had the receiver and speakers on a wooden table and the turntable on a small metal table separate from the rest.
 
I have had a similar problem with my AR turntable and the loud hum was when the tonearm ground came off. There has to be a ground from the tonearm to the grounds for the L and R outputs. If you can figure out how to temporarily add a separate ground wire from the tonearm to output ground you may get your answer.
 
Occasionally I would get a VERY LOUD hum from my turntable. Scary loud. Afraid it would damage something loud.
it was one of the RCA ends that plug into the phono inputs on my receiver.
It was intermittent, and twisting that RCA end at the phono jack would "fix" it.
All was good unless that RCA end was twisted again, bumped, or jostled.
Lived with it for years. As long as that end wasn't moved there was no hum.
I finally bought a pair of red and white male RCA plugs off ebay and replaced the jacks on the end of my turntable cables. Issue fixed.
 
AvFan said:
I have had a similar problem with my AR turntable and the loud hum was when the tonearm ground came off. There has to be a ground from the tonearm to the grounds for the L and R outputs. If you can figure out how to temporarily add a separate ground wire from the tonearm to output ground you may get your answer.
Click to expand...
Thanks, I'll look into this.
 
goodolpg said:
Occasionally I would get a VERY LOUD hum from my turntable. Scary loud. Afraid it would damage something loud.
it was one of the RCA ends that plug into the phono inputs on my receiver.
It was intermittent, and twisting that RCA end at the phono jack would "fix" it.
All was good unless that RCA end was twisted again, bumped, or jostled.
Lived with it for years. As long as that end wasn't moved there was no hum.
I finally bought a pair of red and white male RCA plugs off ebay and replaced the jacks on the end of my turntable cables. Issue fixed.
Click to expand...
I'm gonna twist the RCA ends of mine a bit and see if anything changes. If so, I'll be doing the same and grabbing some new plugs online. This hum is LOUD. As you said, loud enough that it seems like it would damage something. As soon as I switch to phono without actually even playing a record yet. And once I start a record up, I can barely hear anything going on. Pretty much just loud, obnoxious hum.
 
loudnoises said:
Does the sound change if you touch the table anywhere? Like the arm?
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Not when I touch the tonearm. Only change I noticed is when I shook the cords around a bit and kind of wiggled the GND connector. The hum would kinda go in and out, but not actually go away. Still super loud no matter what.
 
Maybe clean up the 580 ground post and run a ground wire from the 580 ground post to the center screw of the outlet it's plugged into while the TT ground is also connected to the 580 ground post.
Also maybe check the contacts on the cart.
Could be a bad wire.
 
Bucky Badger said:
When was the 580 serviced last????
Could it be a problem with the 580?
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I bought it on eBay a while back and according to the seller and had just been serviced, recapped, cleaned, etc. The problem I'm having seems to only be happening with the phono (everything else seems to work smoothly and sound good when tested), so I assumed it was most likely the turntable? I'm hoping it's not the 580.
 
You might consider letting folks know where you are located.
There could be someone near you that could help you out.
Were a friendly bunch ya know.
 
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