[ginettaman]

Are Tantalum bead capacitors polarity sensitive?
I'm building a clone amp, the parts list said Tantalum capacitors. when I received them they a have + marking for 1 leg., but the schematic's that I can find never show any of the capacitors with a + - orientation.

 

[jogor]

hi ginettaman
yes, they are polarity sensitive. they could burn if you do not observe the correct orientation. it should also be noted that tantalum caps are very sensitive to step voltages. a step voltage leads to a step current that can lead to localised heating and dieelectric breakdown. depending on the source resistance, it is better to derate operating voltage to say 70% (with source resistance ~3 ohms/volt)but if there is no current limiting, manufacturer suggest 30% derating. keep with these guideline and you will be ok. if you could avoid this kind of cap in my opinion the better. check out sanyo poscap for a much better alternative (although such caps are available only on low voltage rating).