mlatu wrote:Huh, as you probably can imagine I didn't see that tiny plus sign.
I'm still curious about what would happen if I used an unpolarized cap there.
You can always replace a polarized capacitor with an unpolarized one. The polarization is a restriction on use rather than being advantageous in any way.
The issue with such a replacement is that you will inevitably be using a different type of capacitor (film or ceramic in place of electrolytic or tantalum, say) and different caps have different characteristics.
It is not at all true that ceramic caps are "close to ideal". Regular ceramics, with dielectrics characterised as things like X7R, have some decidedly non-ideal properties. The main one is that their capacitance varies with the voltage across them. In the audio path, this leads to distortion: as the signal (and therefore voltage) varies, the capacitance varies so the way in which the signal is transmitted varies.
For power supply decoupling, where the voltage is steady, it means that you may not be getting the capacitance you expect: a 10uF ceramic with 12V across it could appear as a 4uF capacitor, for example.
The exception to this is C0G ceramics, whose properties are really excellent in almost every respect. They are very common in small values, and essentially unavailable in larger values.
The big caps at the power input of a module should probably be electrolytic, not because of the polarisation but just because they are among the best caps for the purpose at the value you need. The smaller decoupling caps near ICs can be regular ceramic, e.g. 100nF, because even if they behave as 10nF caps when voltage is applied, they will still do the job. For caps in the audio path, C0G or film are good.
Well, that's my understanding anyway.