Turntable hum

[guspasho]

Hi. I hope this is the right subforum. I have an Optimus LAB-1000 turntable hooked up to a Kenwood KR-4070 which I use to listen to vinyl on my headphones while I'm at work. However, since I set up the system I've had a problem with a loud buzz or hum on the phono channel. I'll get the noise whenever my receiver is on and set to the phono input, and the turntable RCA plugs are plugged in to the receiver, regardless of whether the turntable is playing or not. The noise doesn't occur if my turntable is not plugged into the receiver. I don't get the noise if I use the aux input which I use for my ipod.

I tried looking at grounding. The turntable doesn't have a ground cable and isn't supposed to have one, judging from the manual and even pulling it apart to look inside. The receiver doesn't have a ground either but it has a ground plug for a turntable. I'm confused by this, because the power plug is not grounded.

I am using a power conditioner, or a power strip with power conditioning anyway. A Belkin F9D1000-15 power strip.

But my basic question is: how do I get rid of the hum? I've read a lot of topics about other peoples' hum problems and I still have no idea what I should do. I need a simple and cheap answer, replacing my equipment or an expensive, dedicated power conditioner would be excessive for my setup. I'll probably replace the components eventually but I'm not eager to right away. Thanks in advance.

EDIT: I should clarify for you audiophiles that the hum level is pretty loud. Whenever the music isn't totally loud it's audible, and it's always there when a song fades out.

 

[mikeski]

Just some thoughts. What kind of cartridge? Have you attempted any grounding? Have you tried the TT hooked up to a different receiver?

 

[hakaplan]

It's not supposed to have a ground wire. Apparently this uses a p-mount cartridge--make sure it's plugged into the arm all the way and that the stylus is pushed up into the cartridge all the way. You might want to purchase a cheap backup cart to rule it out. The AT-92ECD for under $30 at Amazon is a decent p-mount and possibly better than what you have on there now.

At least one version of this tt has a built in preamp, so that if set on, you could plug the tt into a line level input in your receiver. You could try that just to see if the hum persists.

Barring any of that, the most likely source is bad RCA cables, a common problem. You'd have to solder in a new pair. Video component cables (Red green blue set--use only two obviously) work well for phono, but if you use the inboard preamp you can use anything--any cable will work for line level.