tantalum 680nf - which side on this one?

[boratto]

Hello firends, i got some 680nf tantalum (polarized capacitor), to use on this circuit. Can you tell me which side is positive or negative on the layout?

[Jopn]

Unfortunately, the answer is "neither".  Your best bet, if you need to use polarized, would be to put the positive at the top (connecting to the Input track).  But from what I understand it's not really ideal to use polarized caps in the signal path like this.

[induction]

Put the positive side on the transistor base (~0.7 V = one diode drop above ground) and the negative side on the input (0 V).

It's ok to have polarized caps in the signal path as long as one side of the cap is always at a higher voltage than the other.

It's best not to use polarized caps here, but with reasonable output pickups it shouldn't die. It would take a pickup signal amplitude of over 700mV to violate the polarity, but it will only do so temporarily. Nonetheless, reliability concerns would suggest using a nonpolar cap here.

[boratto]

Thank you both guys for the tips... think gonna with a big poliester 63v instead.