Buzzing noise from aux in Sansui 4000

[afitter]

I recently bought a Sansui 4000 receiver and am getting a buzzing noise when connected to my computer through aux. My current set up is aux going to my computer and phono 1 going to my Audio Technica LP-60. Records sound even better than I hoped they would, but aux has been a problem. The buzz is present on all inputs and does not get louder when increasing the volume. When I remove aux, the buzz remains, but is barely perceptible. When I remove the phono input, the buzz disappears entirely. I've also tried plugging aux into my phone and laptop and the buzzing persists from both.

I'm assuming that this buzzing is also related to distortion of audio in video, especially in videos of lower quality like YouTube. Also, because I didn't notice the distortion until a couple days ago and because the buzzing has become more perceptible (not sure if it's getting worse or if it's perception), I'm currently leaving the receiver off for an hour or so to determine if heat or some other factor related to the receiver being on too long is the cause. I'm absolutely terrible at remembering to turn the thing off. I'm trying to get better at it.

 

[slimecity]

deleted

 

[slimecity]

There is a sticky on this site somewhere about ground loops - suggest you start there.

Chances are that your computer wont have an earthing connection to the powerpoint, while your Sansui may be earthed.

Otherwise - go through that thread step by step to try to eliminate the loop. It can be frustrating to resolve sometimes.

 

[afitter]

Both the buzz and the distortion are less perceptible after the receiver was off for about an hour. Also, turning the bass all the way down and the treble all the way up removes nearly all the distortion, but does not affect the buzzing.

 

[afitter]

There is a sticky on this site somewhere about ground loops - suggest you start there.

Chances are that your computer wont have an earthing connection to the powerpoint, while your Sansui may be earthed.

Otherwise - go through that thread step by step to try to eliminate the loop. It can be frustrating to resolve sometimes.

I wasn't able to find the post you're referring to, so I googled some solutions to ground loop problems. To be honest they're a bit over my head and don't seem very applicable to my situation as most are giving fixes for problems related to cable TV.

That being said, I've play around with the receiver a bit more. While plugging in a cable to the aux ports, the left port pops and hums. It's louder when the cable is plugged into my computer, less loud when plugged into my phone, and even less when not plugged into anything. Also, when the cable is not plugged into anything (i.e. it is plugged into the receiver, but the opposite end isn't plugged into anything and is not making contact with anything conductive.) the buzz can be heard though it is faint.

 

[afitter]

I wasn't able to find the post you're referring to, so I googled some solutions to ground loop problems. To be honest they're a bit over my head and don't seem very applicable to my situation as most are giving fixes for problems related to cable TV.

That being said, I've play around with the receiver a bit more. While plugging in a cable to the aux ports, the left port pops and hums. It's louder when the cable is plugged into my computer, less loud when plugged into my phone, and even less when not plugged into anything. Also, when the cable is not plugged into anything (i.e. it is plugged into the receiver, but the opposite end isn't plugged into anything and is not making contact with anything conductive.) the buzz can be heard though it is faint.

EDIT:
The distortion is now also present on phono. I've just started noticing it over the weekend and it appears to be getting worse.

 

[slimecity]

You want to do some research on this and eliminate it as a problem first:

http://www.epanorama.net/documents/groundloop/basics.html

 

[stereoguy70]

Has the receiver been worked on? Meaning, has it had its electrolytic capacitors replaced or are they the original grey colored Elna caps in the receiver still? If they are original, the buzz you are hearing that increases with use/heat is most likely them starting to fail. They would be 45+ years old now and you would be on borrowed time if this is the case, in which case a recap of the electrolytic caps is in order. Speaking from experience here on this one.......I own one that is as old as I am.....a recap fixed about 99% of the issues I was having with mine.....the other 1% was cleaning the switches & controls and replacing a failed transistor (most likely caused by the failing/failed caps)