Re: extension cables

["Philip Tyler" macmang4125]

This info from Mogami.

Microphonic noise is caused by the minute voltage generated when a cable is 
flexed, stepped on, etc. Some cables are designed to prevent this with a 
conductive PVC layer placed under the shield conductor to drain away this 
voltage. This is usually associated with high impedance circuits driven by 
voltage with very little current flow.

So it may be a function of this that is causing your problems, if your 
unbalanced cable does not have this conductive layer you could try a length of 
some that does and see if that helps.

Phil