John Williamson wrote:
sm_jamieson wrote:
On Mar 4, 4:37 am, The Natural Philosopher
wrote:
sm_jamieson wrote:
My approx 9 year old AV amp started buzzing / humming sounds like
100Hz, slowly got louder until drowning out the music ! PSU caps I
should think. They are labeled "kenwood for audio".
I've got the bigs caps out, they are 10000uF 80V. Lots around for
about 20quid each, or some ebay ones which I try to avoid if possible.
Does this look OK ?
http://connect-audio.co.uk/proddetai...000U80&cat=219
Does the life seem a bit short (I know this is at the max temp) ?
Also saw this but the lead spacing and layout is wrong:
http://parts.digikey.co.uk/1/1/91787...ect-tha-series...

I did not realise the life was so limited though. I've left the amp on
24 hours a day on standby for years !
Also a couple of smaller 3300uF 50V jobs, I guess for a 5V or similar
supply for the ICs, DSP chips etc.
Probably worth changing those as well.
OR ..
Is this really worth my time and up to 50 quid fixing ???
A new replacement would cost 350 quid but would support blue ray
audio, HDMI etc.
Simon.
Seems overly expensive for reservoir caps.

Definitely worth fixing tho.

But you shouldn't be paying much more than a fiver..try fleabay.

There are some caps (more expensive) marked "for audio" etc.
Is this just marketing, or is there anything different ?
Surely in the power supply they cannot make much difference ?
I am sceptical myself.

Because of the way they're made, electrolytics may have a significant
self inductance. I remember in the past buying low self inductance
versions for critical applications, which cost more.


No, low series resistance. If inductance is an issue, you put a smaller
cap across them.

That takes care of HF impedances.