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Live with A Hum vs. Buy An Outboard Phono Stage

It appears that I have an airborne hum that I can't seem to track down. I've done all the usual things (use cheater plugs, shorted ICs, etc.). Now, I am wondering if I should just ditch the whole effort, and buy an outboard phono amp, ala Bellari, Creek, and such. The turntable I have won't set the world on fire, but it does a more than adequate job if given the chance.

So, opinions please. Is it worth getting a phono stage, and plugging it into a dead-silent input, or will it suffer from the same thing?
licoricepizza
mapman's avatar
mapman
21,891 posts
 
Have you tried physically moving the pre-amp with the phono stage around to see if the hum level changes with location?

If so, it is inductance hum from some nearby power transformer, possibly in power amp or other component(s) or other external source.

If you haven't already, try this first to determine if that is the problem. If so, switching to an external phono stage is not necessarily the solution. Addition shielding and/or relocation of components for better separation is.
licoricepizza OP
48 posts
 
The only moving of the preamp has been to move it to a separate shelf by itself (no discernible difference). When I connected different amp, they were about 3' apart. No difference then either.

This morning, I put a metal widow screen behind the stereo to act as a shield, hoping the noise was coming from that direction. It was a no go.
mapman's avatar
mapman
21,891 posts
 
You may have a different problem yet this site provides some potentially useful shielding and measurement solutions.

http://www.lessemf.com/mag-shld.html
licoricepizza OP
48 posts
 
After looking at the website, I'm wondering if I can anything like that at Home Depot, or Lowes.
licoricepizza OP
48 posts
 
An Update - which I hope is final.

The hum doesn't appear to be grounding related. Instead, it appears to be thermal in nature. If I turn off the amp, but leave the preamp powered up, there doesn't seem to a problem. For 2 days in a row now, there's been no hum.

If it ain't broke, I won't fix it.

Thanks to those who helped.

Lee

The problem appears
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