Audacity Forum

JCook wrote:I tried plugging in directly to the line-in port on the back of my Mac, and was able to record, but there was a fairly loud low hum that I couldn't get rid of, so I'm back to using the iMic until I can figure it out. It's probably some sort of ground problem I would think,

That sounds likely. Do you have an "earthing wire" between the turntable and the amp? If not, have a look to see if they have a place to connect one - in nearly all cases this will have a beneficial result, but sometimes makes no difference and very occasionally makes things worse, so if this wire is already connected it may be worth testing it without (it's most likely to make the hum worse, but for the 10 seconds that it take to try...)

I'm not running a laptop but a tower, so it has to be plugged in. I'll flip the plugs and see what happens. Also, I'll plug 'em into the same power strip. And clean the 1/8" plug.

kozikowski wrote:Even more exotic, if you are working with a entertainment wall, unplug the roof antenna or cable TV connection. Go ahead. Ask me how I know that one.

OK. How do you know that one?

stevethefiddle wrote:That sounds likely. Do you have an "earthing wire" between the turntable and the amp? If not, have a look to see if they have a place to connect one - in nearly all cases this will have a beneficial result, but sometimes makes no difference and very occasionally makes things worse, so if this wire is already connected it may be worth testing it without (it's most likely to make the hum worse, but for the 10 seconds that it take to try...)

Yes there is an earthing wire from the turntable, and it is connected. I'll try unconnecting.

thanks,
Jack

<<<OK. How do you know that one?>>>

I got burned. I was recording radio shows off the air and my tuner is connected to a roof antenna. No cable system or community antenna or anything magic. There was always a low buzz running through everything no matter what I did. I grounded, I lifted grounds, I tested the wall power, I went nuts. No luck, so I started disconnecting things until I got to the antenna and the problem vanished. Hum went to zero. I put everything back together except for the antenna and I still had a quiet system.

I bought an adapter Jensen Transformers makes (it's not actually a transformer) that isolates the grounds in the antenna cable without interrupting the television and radio channels.

Not three weeks later, someone in the shop was complaining about hum in his music system that he couldn't isolate....

Koz