Coupling/Signal cap voltage rating

[zpyder]

I understand that for any cap that is over a typical 9v supply, it's a good idea to have a cap rated for 15v+ (ballpark) - but what about your average coupling or decoupling cap?  Could I get away with using a 6.3v cap for, say, decoupling between a TL072 and output?  Good/bad?

zpyder

[R.G.]

It's a bad idea to use caps rated for less than the power supply voltage unless the circuit design is such that it will prevent the voltage on the caps from ever exceeding the rating - even under the consequences of a single component failure. Using low voltage caps in conditions where one other component failing will cause the cap to fail amounts to laying a trap for yourself if you ever do have that failure. For DIY effects, people are forever reading something that will make them want to run their pedals on 12, 15, 18 or more volts.

I consider 16Vdc caps a minimum for effects except in special circumstances.

But that's just me.