Thanks for the description, Dan. Makes perfect sense! Does it also mean
if wired unbalanced it does not matter if pin 3 is grounded or
unconnected? Would one or the other way have better noise performance?
And this may be wandering off topic, but dbx 150X NR units specify that
if wired unbalanced, the ring (of its TRS output) must be unconnected,
not shorted to ground. Why might that be, since you can describe
ciruits for the non EE types such as myself... reply offlist if this is
too far off the topic. The dbx is the only thing I have seen that says
to do that.
Thanks,
Lou
On Sep 2, 2005, at 5:14 PM, Dan Dugan wrote:
> derek holzer wrote:
>
>> Spec says:
>>
>> Symmetrically ungrounded output without repeater
>
> I suspect this refers to what I call "source impedance balanced." I
> understand that's how Neumann mics are wired. It's what I do with the
> outputs on my products.
>
> It means that pin 2 is driven with the signal, and pin 3 has a
> passive network that matches the source impedance of the signal
> channel. It turns out that this arrangement has all the
> noise-rejecting qualities of a symmetrically-driven balanced output,
> without the extra amplifier and the attendant complications when the
> user wants to wire it unbalanced.
>
> The only downside is if somebody tries to run it unbalanced out of
> pin 3. No signal.
>
> -Dan Dugan
________________________________________________________________________
________________________________________________________________________
|