API

Help with caps for API 550A Eq.
« on: October 16, 2006, 11:42:32 AM »
Hi.
I am currently recapping my API 550A eq´s and have a few questions.
In the original schematic the filtering caps for the power rails (+ - 16v) are 10/25v, but in a later schematic i have wich is dated ca 1980 these have been upgraded to 100/35v.
Is it just a question of size/value (caps getting smaller/ratings higher), that they would have used 100/35v from the beginning if they could have fitted them?
Also, in the later 554 eq schematic they also have the 100/35v caps in this place.
Should i use the higher value here??

Then there is a small 0,47 electrolytic in there.
Could not find that value in the Panasonic caps i use, but found another one that was non-polarized.
Would this be ok as a substitute?
Any advantages/disadvantages to use non-polarized caps??

And last the output cap (500/6,3v vs 470/16v).
Again this have different power ratings in the different schematics.
6,3v in the early and 16v in the later.
Would there be any audible difference??
I guess not, but i thought i would ask.

Regards,
Dennis


mikep

Re: Help with caps for API 550A Eq.
« Reply #1 on: October 16, 2006, 11:14:06 PM »
Quote from: "API"
would have used 100/35v from the beginning if they could have fitted them?


maybe.  I dont think it matters either way.  The ESR makes more difference than the value.  Id use a panasonic FC 100u, because I have them on hand.

Quote from: "API"

Any advantages/disadvantages to use non-polarized caps??

maybe.  A nonpolar cap might last longer if it has alot of AC current flowing thru it.  it will likely be twice as big as a polarized cap, and probably only available in a radial package.   probably no detectable difference in sound. maybe if you recapped a big console with 100s of them in series, but I wouldn't personally say either is better.

Quote from: "API"

And last the output cap (500/6,3v vs 470/16v).
Again this have different power ratings in the different schematics.
6,3v in the early and 16v in the later.
Would there be any audible difference??


audible? nah. but all other things being equal, the higher voltage cap will probably last a little longer in this position. especially if the output is always patched into a low-z input and passing high levels.  or maybe put a nonpolar cap here if you want to get fancy.  personally I wouldnt bother. 470/16 or 470/25 if it will fit.

mike

API

Help with caps for API 550A Eq.
« Reply #2 on: October 19, 2006, 06:28:04 AM »
Hi.

Thanks for the input.
I have now ordered the parts and will start to recap soon!

Regards,
Dennis


 

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