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Balanced Not really and Ground Hum

I have read that some balanced outputs (coming from any component) are not truly balanced, rather the manufacturers use RCA output wiring hard wired to the XLR output making the XLR unbalanced or not a "true balanced signal".
Is this a common practice and anyone come across this if so were?

The reason I ask is that I have been fighting that elusive little call "Hum or Ground Loop".
I have tried everything to solve it, disconnecting everything, adding Power Conditioners, Filtered AC cables, different RCA’s and now Dedicated Power (try explaining those three “Gotta Have It” words to the wife) but I can still hear the Hum.

So I am going to sell a bunch of my equipment and buy a preamp with balanced XLR out to my monoblock (Manley Snappers) which have XLR in.
I just don’t want to find it does not solve the problem because the XLR was wired from the RCA output.

Question: If the XLR is wired from the RCA beside the obvious audio consequences will it nullify the XLR = Less hum fact?
punkuk

Showing 1 response by sbank

sbank's avatar
sbank
3,391 posts
 
True balanced will help fight RFI and noise in general, and is a great idea, but really should be necessary to rid your system of a ground loop.
I suggest you read the archives on ground loops, both here and at audioasylum. Then I'd try borrowing other gear(e.g. cheap reciever) and trying to see if you can eliminate to isolate which component is causing the trouble. If you can narrow it down to your pre, call the manuf for suggestions. One obvious one is wires touching each other. Make sure your cables cross at right angles when possilbe and that no power cables touch each other or any interconnects.
Turntables are notorious for loop issues, so first try just CD, resolve the digital/amp/pre then add analog back and see if you still have no hum. Good luck,
Spencer
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