Replacing bipolar coupling caps in Lexicon processor?

[Wilf]

Hi folks,

Made a few searches on here to find comparisons but wasn't lucky.

Looking to replace some probably very 'tired' 47uf Bipolar 25v Electrolytic interstage coupling caps in my processor and will be removing them for another seperate mod anyway I thought I'd look for suitable replacements, something better, but found it hard to find the same bipolar type to start with anyway.

Any suggestions? I don't know why Lexicon fitted bipolars, I'd of thought the DC bias direction was to this cap. There are the same again at the last op-amps as well.

They're prolly quite old now as well.

I've looked & looked at capacitor PDF's and specs and just can't make any idea what to fit, having a very hard time finding supplies of non-polarised electro's.

Could i use a lower value uf polypropylene type instead?

Any help appreciated, tah.

Wilf

[stephensank]

I think you will probably find, if you take measurements, that Lexicon used the bipolar caps because there is 0volts, or damn near, on the cap. It is very likely that the cap is completely unnecessary(save for the rare event of opamp chip failure), and could be replaced with a piece of wire. No cap is always best when possible in any signal path.