General Forum

Re: To use low ESR capacitors in Penta Amplifier or not?

Dillen — Mon, 21 Dec 2009 02:58:56 GMT

There's a kit available that contains foil caps for the crossovers, WIMA-II caps for the signal path and 105deg general purpose caps
for the other electrolytics.
Low-ESR is not at all as important as 105deg. It can get very warm inside the Penta amp casing and that's what kills the
original caps.
The kit also contains new op-amps, also worth doing.

Martin

Re: To use low ESR capacitors in Penta Amplifier or not?

Die_Bogener — Mon, 21 Dec 2009 02:58:06 GMT

Just the 4 red caps need Wima caps, all other are for the power supply.

You can replace them with low ESR types, but this is not really necessary and the heat inside is moderate. There will be no difference.

... and dont forget the BurrBrown opamp OPA 2132 or OPA 2134

To use low ESR capacitors in Penta Amplifier or not?

MartinM — Sun, 20 Dec 2009 20:35:26 GMT

I’m in the process of restoring a pair of Penta MK2’s. So far have refoamed the mid-ranges and recapped the filter boards. Am now going to replace all the capacitors on the Amplifier board in the base. Has anyone done this, and to this extent? Am thinking of using Nichicon capacitors but am unsure as to whether I should go for the low ESR rated ones or just get general purpose ones.

For the capacitors in the signal path I’ll be using WIMA and for the 10,000uF caps, Cornell Dubilier.