star grounding in a city rental apartment

simple2211 · Post by **simple2211** » Mon Feb 06, 2006 12:43 pm

i have a small synth/sampler studio in my apartment and am encountering some very quiet 60hz buzz in the audio signal. everythings running to one ac receptacle which has been tested with a radioshack outlet tester and found to have suitable ground.

I would like to implement a star ground system but i am in a rental apartment. I can't do anything to the ac nor can i drive a copper rod into the ground.

what are my options? I've read alot of posts regarding star grounding but none address my specific situation. i've read about running all the ground wires to the mixer and my mixer does have a grounding post but the mixer manual says that it should not be used as a grounding point for other gear. furthermore the mixer is unbalanced and most of my gear is unbalanced as well. i also have read about using a water pipe as ground but i'm not sure if this would work and i don't want to do anything risky.

any suggestions would be greatly appreciated.

Post by **kendale** » Mon Feb 06, 2006 8:55 pm

Aloha and welcome to the forum!

Any chance you could please:

Edit your profile to include your location. This is very important, because this is a worldwide resource, and as such, material costs and availability vary widely. For example, masonry is cheaper than gypsum in some parts of the globe, whereas it's the exact opposite in other regions.

This will really come in handy two or three posts down the road. It's also part of the forum guidelines: http://www.johnlsayers.com/phpBB2/viewtopic.php?t=3231 Thanks!

Aloha

simple2211 · Post by **simple2211** » Tue Feb 07, 2006 1:31 am

Sorry bout that, I am in New York. Profile edited.

Post by **kendale** » Tue Feb 07, 2006 7:41 am

Aloha,

Thanks for updating your profile!

Have you considered this as a possibility? http://www.furmansound.com/products/pro/blncd/it-20.php

One thing that's nice about it is that you can take it with you if you ever have to move.

Hope this helps,

Aloha

simple2211 · Post by **simple2211** » Tue Feb 07, 2006 8:35 am

Yes! I just bought one on a trial basis and its being shipped to me as I type. Hopefully it will help. (It better considering the cost!)

I've heard/read conflicting info regarding balanced power and grounding. Some sources (such as the manuafacturers) say that grounding problems are not as much of an issue when using balanced power. other pros say that if you don't have a good grounding scheme in place then balanced power won't help you.

Well being that I have had great difficulty tracking down the buzz I figure it would be good to implement a star ground system if possible under my circumstances.

knightfly · Post by **knightfly** » Tue Feb 07, 2006 9:57 am

In additon to the balanced power, since your stuff is all unbalanced you might get better results by grounding all your chassis to a common star point (like the mixer) and then using telescoping shields (lots of work) - this way, there would be NO POSSIBILITY of any current flow in your shields (main cause of hum) - this may help clarify

http://www.rane.com/note110.html

Steve

simple2211 · Post by **simple2211** » Wed Feb 08, 2006 1:50 am

wow telescoping all the shields would be alot of work, so it would probably be my very last resort (before audio transformer isolating everything which would be very very expensive). if i did this what end of the cables would i lift--the component side or the mixer side?

knightfly · Post by **knightfly** » Thu Feb 09, 2006 8:36 pm

The component side; the mixer would be your star point. And yes, it's a major pain - the least painful approach (should it prove necessary at all) is to make a test cable or two - disconnect one thing at a time til you find one that makes a MAJOR diff in noise, then replace just that cable with a telescoping shield. Repeat til the noise level is low enough. Sometimes it only takes one or two components isolated this way to fix things... Steve