Quad 707 Factory Build Error

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23-Jun-2018 04:37 AM

circlotron

circlotron

Posts: 8

When working on my 707 I discovered that three of the four power supply caps were 15000uF at 40V rather than 15000uF at 63V. Surprisingly they had not failed (yet). They were BHC ALP20A153DE040 UK Made. I saw no signs of rework on the PCB and am quite sure they are original. The fourth cap was the correct BHC Aerovox ALP22A153DE063 UK Made.
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29-Jun-2018 09:37 AM

EJP

EJP

Posts: 1530

Very interesting. Quad don't actually make anything that takes 15,000uF 40V capacitors. I wonder if it was a supply mistake? Would explain how it didn't get noticed. There is a voltage margin of course beyond the rating, but they would still be very close to over-voltage.

EJP

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