[sdiy] What is this capacitor in the JP8?

[Tom Wiltshire]

Hi Jack,

> Thanks. Is the 50v an important factor here, or was it just specified so people wouldn't use something too low like 16v for example? I've found some cheap 100v ones here. 
> http://www.hificollective.co.uk/catalog/rbd030-047uf-100vdc-elna-bipolar-capacitors-p-9449.html

If the schematic says 50V, we have to assume that they worked it out, taking all the factors that Neil mentioned into account, then added what they thought was a reasonable margin of error*. So anything >=50V should be fine. Sometimes higher voltage caps have a difference tolerance, so you might consider that - a 50V part might be 5%, but the 100V part might be 10%.

> Also why they choose to use an electrolytic over a polyester?

What Neil said. It was what they had, or what they could get cheap, or what would fit in the space left on the PCB. Whatever it was, I'd bet money it wasn't because someone thought it sounded better. If it does, that's a happy accident.

HTH,
Tom