Hi.
when replacing electrolytic capacitors, are there specific types that need to be chosen?
what i mean is, when removing say for example a 6800uf 50v cap, which are relatively easy to source, there are many other things it seems to consider when you look at the filter choices.
There are no details of what these are on the original caps so how would i know for example what the leakage current,ripple current and series are? do these matter much, i guess they must do or they wouldnt be there as a choice or are these for more critical applications than for an audio amp?
i obviously dont buy any rubbish,i only get, where i can, panasonic,nichicon,rubycon etc but i always wonder about the other filters and whether they are important.
many thanks
paul
when replacing electrolytic capacitors, are there specific types that need to be chosen?
what i mean is, when removing say for example a 6800uf 50v cap, which are relatively easy to source, there are many other things it seems to consider when you look at the filter choices.
There are no details of what these are on the original caps so how would i know for example what the leakage current,ripple current and series are? do these matter much, i guess they must do or they wouldnt be there as a choice or are these for more critical applications than for an audio amp?
i obviously dont buy any rubbish,i only get, where i can, panasonic,nichicon,rubycon etc but i always wonder about the other filters and whether they are important.
many thanks
paul
If the cap is not used in a switchmode supply or amplifier, then any reputable brand sourced by a reputable supplier should serve well. For switchmode work, there are caps designed specifically for that sort of an application, and a standard cap without ultra low ESR and ESL will not work well in such a setting.
For power supply capacitors in power amplifiers, you want high ripple current and 105C high temperature types,
for a long useful life. Usually you calculate the expected ripple current, and use a part that is the same or better.
Always use a voltage rating significantly higher than the circuit voltage, such as at least 35V or more, for use
with a 25V supply. Better parts do cost more, so they are mostly used when needed, not routinely.
Some sensitive circuits will need low leakage capacitors, or parts with better drift and accuracy.
for a long useful life. Usually you calculate the expected ripple current, and use a part that is the same or better.
Always use a voltage rating significantly higher than the circuit voltage, such as at least 35V or more, for use
with a 25V supply. Better parts do cost more, so they are mostly used when needed, not routinely.
Some sensitive circuits will need low leakage capacitors, or parts with better drift and accuracy.
Last edited:
For a traditional transformer based passive supply just get as big a capacity, high ripple, low ESR value within the voltage limit as you can fit, if you don't have much experience and it's a one time job I would suggest audio marketed caps from a reputable manufacturer.
All low leakage type caps such as tantalum and light blue and orange need to be replaced with low leakage types otherwise noise will be higher after recap
I'd say no, fit the same capacitance value (or the next available value up) only. If you make the reservoir capacitors much larger this will stress the other components much more during the turn-on surge, risking a cascade failure of perfectly servicable parts such as the rectifiers - not a good idea if you're trying to extend the life of the device... Many commercial amps are designed with parts just good enough, so adding extra stressors is a risky business.
Theoretically maybe but not in my 20 plus amp mods/renovations experience.
The typical stress part is the diod bridge which usually can take a lot more than a 200-1000w trafo can deliver (you can check the spec before you decide).
I remember many years ago adding +-200,000uF to the std +-22,000uF per channel and 20 years later it was perfectly fine in spite everyday use and still fully operational. The audio quality benefits were huge btw, total control and authority. Now these did not fit into the cabinet so with that limitation you will maybe be able to double whats there now which is absolutely a non issue.
You could go with the 6800uF with 63 Volt rating if this fits the space you have. The ripple rating is a little better than the 50 Volt component and it should have a longer life without stressing other supply components.