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Discussion Starter · #1 ·
Hello everyone,

I have a vintage Pioneer receiver, and a new Audio Technica turntable.

If I connect the turntable to the phono input on the receiver, then there is a horrible hum, like it needs to be grounded. The receiver does have a screw to connect a grounding wire, but the turntable is internally grounded and doesn't have anywhere to connect a wire.

However, if I turn on the turntable's built-in pre-amp and connect it to one of the auxiliary inputs on the receiver, then it works with no hum at all. This would be just fine, except I want to use that auxiliary input for something else.

How can i get rid of the hum with phono input?
 

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What model do U have? AT-LP120-USB

If yes, this cannot be connected to your phono input as it has its own built-in preamp section. And your vintage receiver also has a preamp section thats why U have a hum..
The turntable needs to be connected a high level aux or tape input...
Your vintage receiver should have more high level inputs labeled Tape monitor, Tape play, Aux...
Any of those will work..

Just my $0.02... ;)
 

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Discussion Starter · #3 ·
Yes it is the AT-LP120-USB. It has a little switch on the back to output either at "phono level" or "line level." I figured that setting the switch "phono" meant that the pre-amp was turned off, to connect to a receiver's phono input. That's based on the product documentation.
 

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Discussion Starter · #4 ·
Yes it is the AT-LP120-USB. It has a little switch on the back to output either at "phono level" or "line level." I figured that setting the switch "phono" meant that the pre-amp was turned off, to connect to a receiver's phono input. That's based on the product documentation.
I just looked up the manual and verified that setting the switch to "phono" does bypass the internal preamp.
 

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If U are going to bypass the built-in preamp in the turntable and connect to the phono input of the receiver. U should run a ground wire from the turntable to the receiver...

Just my $0.02... ;)
 

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Discussion Starter · #6 ·
I did try running a wire from the receiver grounding screw to the tonearm on the turntable, but the hum was still there. :(

I wonder if I need better-shielded RCA cables. I disconnected them from the turntable so there were just the left and right wires dangling from the receiver phono input, and the hum was still there.

As I mentioned, there is no hum at all when I connect the turntable to auxiliary input and switch on the turntable's built-in pre-amp. But the receiver only has two high-level aux inputs (the main one and the tape monitor), so I really want to connect the turntable to the phono input so that I can use both of the aux inputs for other components.
 
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