Author Topic: Source for computer/audio grade electrolytic capacitors  (Read 1498 times)

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Offline mgl99

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Source for computer/audio grade electrolytic capacitors
« on: February 05, 2018, 05:38:39 pm »
I am looking for the primary filter caps in the vintage amplifier I am restoring.  What I'm looking for is two Nichicon 18000uF electrolytics rated at 63 V.  If they are screw connected, how can I get adapters to screw in and provide solder spade connectors to mount on the circuit board?  I've searched all of the sites that commonly sell capacitors.  I know that Nichicon makes these as I have seen them used in other restorations. 

Thanks guys
 

Offline Twoflower

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Re: Source for computer/audio grade electrolytic capacitors
« Reply #1 on: February 05, 2018, 05:54:51 pm »
Because the huge capacitance these caps are probably used as filter cap after the bridge rectifier. If that's the case you can increase the capacitance to the next common value (e.g. 22000µF).

Also you should check the number and position of the pins to find a matching type. Probably the new ones are (much) smaller than the original ones. In case you only for whatever reason get only caps with screw terminals: Use crimp O-rings and cables.
 

Offline Nusa

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Re: Source for computer/audio grade electrolytic capacitors
« Reply #2 on: February 05, 2018, 05:56:27 pm »
Search for "bolt mount spade terminal" for the adapter question.
 

Offline Twoflower

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Re: Source for computer/audio grade electrolytic capacitors
« Reply #3 on: February 05, 2018, 06:17:49 pm »
One more point: You should consider to use 'normal' caps. They most likely have already a much lower ESR than the original caps (depending on how vintage the originals were). If you use low ESR caps the inrush current might trigger the fuse and are harder for the rectifier during power on.
 

Offline EHT

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Re: Source for computer/audio grade electrolytic capacitors
« Reply #4 on: February 05, 2018, 09:17:35 pm »
I notice Nichicon do a special range of electrolytics marketed for audio, the highest-end one being "KZ". For "where qualitative and quantitative comfortableness is required". Indeed.

https://www.mouser.co.uk/new/nichicon/Nichicon-Audio-Caps/

Farnell only have them on special delivery but Digikey have them in stock. The PSU-sized ones (> 1,000uF) seem to be silly prices but the low value ones are cheap enough.

I have a couple of caps to replace which are low value in the signal path, so these seem like a good choice. Otherwise, I guess for replacing any in linear PSUs the factors should be high ripple current and reliability? (noting the comments above about modern Low-ESR probably being too low).

Regards






 

Offline mgl99

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Re: Source for computer/audio grade electrolytic capacitors
« Reply #5 on: February 05, 2018, 11:37:51 pm »
Mouser was the first place I checked.  I don't see where they sell a Nichicon 18000uF @ 63 V.
 

Offline DaJMasta

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Re: Source for computer/audio grade electrolytic capacitors
« Reply #6 on: February 06, 2018, 04:11:27 am »
Don't bother with specific "audio" caps.... they're just decent quality regular ones with a fancy name and a jacked up pricetag.  If you want premium caps, look for higher voltage rating, higher temperature rating, lower ESR, etc.... nothing about "audio grade" caps make them inherently superior to other good grades from good brands for any sort of audio work.


There's also nothing wrong with going with higher voltage ratings, so if you can't find a 63V like the original, anything larger will still do (though they usually get physically larger and more expensive).  There's also the option of putting several caps in parallel - While still only with substantial solder tabs, it gives you some flexibility in wiring options and trying to fit differently sized caps somewhere in the existing chassis.  If you find something that fits your form factor that's a higher capacitance, that would also be a fine option - something of this size is not going to be picked for a really specific value, they just wanted as big as was easy to get to be a big reservoir of power on demand, so while a lot less is probably bad, a little less - even 20% or so - is probably not a problem, and any amount more is fine too.


Oh and if it wasn't clear, there are caps of that size that have solder terminals - a quick search at digikey showed several options that would work.  Then there's also the screw terminal type, the older axial style, then stuff that's better suited to spade lug connections and the like.
 
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Offline Bashstreet

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Re: Source for computer/audio grade electrolytic capacitors
« Reply #7 on: February 06, 2018, 08:38:48 am »
Don't bother with specific "audio" caps.... they're just decent quality regular ones with a fancy name and a jacked up pricetag.  If you want premium caps, look for higher voltage rating, higher temperature rating, lower ESR, etc.... nothing about "audio grade" caps make them inherently superior to other good grades from good brands for any sort of audio work.


There's also nothing wrong with going with higher voltage ratings, so if you can't find a 63V like the original, anything larger will still do (though they usually get physically larger and more expensive).  There's also the option of putting several caps in parallel - While still only with substantial solder tabs, it gives you some flexibility in wiring options and trying to fit differently sized caps somewhere in the existing chassis.  If you find something that fits your form factor that's a higher capacitance, that would also be a fine option - something of this size is not going to be picked for a really specific value, they just wanted as big as was easy to get to be a big reservoir of power on demand, so while a lot less is probably bad, a little less - even 20% or so - is probably not a problem, and any amount more is fine too.


Oh and if it wasn't clear, there are caps of that size that have solder terminals - a quick search at digikey showed several options that would work.  Then there's also the screw terminal type, the older axial style, then stuff that's better suited to spade lug connections and the like.

Yeah no need to spend 50 pounds into "Audio" Cap what might even be inferior to 2 pound cap... just marketing wank to make fools part with their money.
 

Online BravoV

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Re: Source for computer/audio grade electrolytic capacitors
« Reply #8 on: February 06, 2018, 09:11:01 am »
Don't bother with specific "audio" caps.... they're just decent quality regular ones with a fancy name and a jacked up pricetag ... and fancy/silly case or jacket.

Highlighted my addition above at quote ...  :P

 :palm:


Offline DaJMasta

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Re: Source for computer/audio grade electrolytic capacitors
« Reply #9 on: February 07, 2018, 02:00:25 am »
It does look nice, though.  ENIG finish with a black solder mask with some gold caps if you really want to bling out your amp.... it's not gonna sound any different, though  ;)



You'd think with the extra pricetag they'd at least gold plate the leads or something  :-//
 

Offline KhronX

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Re: Source for computer/audio grade electrolytic capacitors
« Reply #10 on: February 10, 2018, 08:07:50 pm »
I see a niche in the market...  ;D

You'd think with the extra pricetag they'd at least gold plate the leads or something  :-//
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