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 newbee

Are you saying that you totally disassembled your components and then added them back into the system, one at a time, and you didn't notice the reappearing hum at the time the offending was reinserted into the system? I agree with the above re ground loops v balanced.

If you start with sources, removing one at a time, you should notice when the cause disappears. If not, then when they are reassembled, one at a time starting at the amps it should appear. Just let some time lapse between each change - sometimes hums take a bit of time to reappear due to warm up issues, etc. (I have amps which hum immediately, and others that start to hum after substantial warm up. The former I have been able to 'fix' with cheater plugs, the latter not at all absent some overhaul, if that, but much depends on level and speaker sensitivity.

Once you ID the source, the solution is probably a walk in the park.