Capacitors for power supply

Jrp27

Member
2016-04-22 7:27 pm
Quick question....

I am getting some cheap 10,000 uf,100v caps for power supply about $3 each.

My question is that when it comes to power supplies do the quality of caps matter?

Would it make a difference in sound quality if I go for cheaper caps in power supply rather then expensive nichicon /elna ones?
 

Mooly

Administrator
Paid Member
2007-09-15 8:14 am
Quality matters greatly. Look at the specs for E.S.R. (equivalent series resistance) and maximum allowable ripple current.

On top of all that, some obscure brands are poor performers and many cheap caps are fakes. Its common to see a supposed 10,000uf 63 volts cap (say) that is really an empty can with a cheap 2200uf 35 volt soldered internally.

Usually... you get what you pay for.
 

mrWagner

Member
2006-10-27 1:34 pm
Main supply caps shouldn't matter that much. They should be to feed the quicker and smaller low esr caps near the amp. If main psu caps matter much, then the rest of the amp is not built too well.
It is also true that for 3$ you may get fake caps as mentioned before. Lower voltage and or lower storage.
 

us1070

Member
2014-01-25 12:58 pm
Goa
I measured the $3 caps and they give reading of 10000uf on capacitance meter
ESR in high in cheap caps and voltage drop little faster then a original Japanese brand and voltage could be overated.

And i have a question about capacitor voltage:
Till under 100v caps are cheap then it gets a jump in price

limited at 90vdc rails for 100v caps and so is it worth the extra cost for 110vdc rails does this 20vdc make a huge difference in amplifier wattage?
 
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Reform your 100V capactors very slowly up to 100V and measure the leakage current.
A 35-0-35V mains transformer fed from a Variac will allow you to reform in small increments until they either pass the leakage test, or fail due to excessive leakage.

BTW, all electrolytic manufacturers specify a reform cycle shortly before starting any testing/measurement of their capacitors.
 
............limited at 90vdc rails for 100v caps and so is it worth the extra cost for 110vdc rails does this 20vdc make a huge difference in amplifier wattage?
the maximum output power goes up roughly with the square of the supply voltage.
Increasing the supply by 40% will give roughly 3dB more power.

i.e. going from ±50Vdc to ±70V will give roughly double the maximum power and going to ±100Vdc will roughly double it again.