[sdiy] Balanced/unbalanced inputs?

[Tim Ressel]

Naw, not silly. It goes like this:

Unbalanced, or single-ended, is a single wire plus a
ground to return current. the coax from your guitar is
an example.

Balanced lines are pairs of wires, usually twisted.
the signal differentially on the wires. That is, the
signal is on one wire, and the inverted signal is on
the other wire. A balanced input (like on a mixer)
subtracts the signal on the two wires, and this
difference is the result.

The reason for all this hassle is this: noise
rejection. Interference from the outside world will
appear on both wires equally. When subtracted, the
interference cancels out. Neat, yes?

To use an unbalanced line into a balanced input, you
could try attaching the unbalanced line to one of the
balanced lines, and ground the other side. This may
work, but there's a problem: balanced inputs tend to
be higher levels (+4 dBv) than the unbalanced ones
(-10dBv). 

Or you could go to Radio Shack and buy a
unbalanced-to-balanced adapter for about $20.

Does that help?

--TR


--- DTK <aurastar at cox.net> wrote:
> Ok, silly question time...
> 
> What's the difference between balanced and
> unbalanced inputs and outputs?
> What are the consequences of mixing the two? For
> example, using a mixer with
> balanced inputs, and an instrument with unbalanced
> outputs?
> 
> Humor me, please :)
> 
> Thanks
> 
> 
> 



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