48V capacitors question

  Hello, I was reading this http://sound.whsites.net/project35.htm and I was minding why the output capacitors in fig.3 had to be bipolar ?

" Because some degree of mucking about would be normally be needed for the output capacitors to make the unit truly universal, these are specified as bipolar (non-polarised) types - standard electrolytics must not be used. "

I think it is to guard against shorts at the XLR. Normally the right hand side of both caps is at least as high as the 24V supply. The op amps are biased to half the 12V so they sit at 12V. So you could use polarised caps with the pus to the right in the schematic. BUT, if pin 2 or pin 3 is accidentally shorted to pin1 the right hand side of the OP caps are connected to 0V but the op amp is still at +12V so the cap gets reverse biased.

Cheers

Ian

Yes of course!

Thanks Ian, brilliant