[sdiy] DC blocking caps on inputs - or not?

[P Maddox]

>> Another capacitor question popped up:
>> What's your view on having electrolytic caps right at the input of an audio
>> device in order to block DC and/or protect the circuit?
> I think it's not so much a question of "protection," as of allowing you to
> choose the DC bias point of the first stage.  If you don't block DC, then
> anything you connect to that input is going to affect the bias in a
> hard-to-predict way.
I'd agree... I'd go a step further also.
If you don't *HAVE* to use caps in the audio path, don't.
Everything you put in the path affects the signal, so the less you can 
put in the path, the less the signal is messed with.
>
> I'd avoid electrolytic caps in this application because they don't
> tolerate reverse voltage, and so it'd become necessary to protect the cap
> from that, one way or another.  Not so much an issue of signal quality.
>
yeeee, no....

every cap does have a reverse voltage limit, all be it much smaller than 
the forward voltage limit, but you can get caps that work 'bipolar' for 
not much more than unipolar caps.

P