i have this amp almost 30 years old and the main power supply caps have expand.
i plan to change all the electrolytics.
i found two main caps nippon chemicon 4700/63v low profile and
all the rest panasonic fc.
what do you guys think?
is it a good choise?
is it possible the low esr to be bad in some cases or it is always better?
the amp have electrolytics everywhere and no bipolars.
shouldn't the caps in series with the signal be bipolar?
i am not sure if there any but there should be at the input dc blocking caps
i won't go crazy about sq since the amp drives subwoofers i just don't want to make any big mistake.
after recapping should i adjust bias and offset?
i plan to change all the electrolytics.
i found two main caps nippon chemicon 4700/63v low profile and
all the rest panasonic fc.
what do you guys think?
is it a good choise?
is it possible the low esr to be bad in some cases or it is always better?
the amp have electrolytics everywhere and no bipolars.
shouldn't the caps in series with the signal be bipolar?
i am not sure if there any but there should be at the input dc blocking caps
i won't go crazy about sq since the amp drives subwoofers i just don't want to make any big mistake.
after recapping should i adjust bias and offset?
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Polarized capacitors are often used in the signal path. Unless there is significant DC, the bi-polar and polarized caps perform the same.
If you adjust the bias, know that the bias pots are mirrored. Clockwise is up on one. Counter-clockwise is up on the other.
The caps you listed will be OK.
If you adjust the bias, know that the bias pots are mirrored. Clockwise is up on one. Counter-clockwise is up on the other.
The caps you listed will be OK.
If you're referring to the bias setting, I don't have manufacturer recommended values. I'd set it as is shown in the demo below.
http://www.bcae1.com/temp/ausettingbias.swf
http://www.bcae1.com/temp/ausettingbias.swf
i finished recapping with the caps i mentioned.
the main caps where 3800uf from 4700uf
one cap was 900uf from 1000uf and all the rest where ok
the strange part is that all the new caps where within specs but at the low side.
eg the 4700uf was 4400uf the 2200uf was 2150uf the 1000uf 960uf etc
the amp seems to work fine but i didn't put it in the car yet.
i wonder why the chinese caps that i pulled out where all at the high side
eg 2200uf was 2300uf etc only 3-4 of them lost capacitance
the main caps where 3800uf from 4700uf
one cap was 900uf from 1000uf and all the rest where ok
the strange part is that all the new caps where within specs but at the low side.
eg the 4700uf was 4400uf the 2200uf was 2150uf the 1000uf 960uf etc
the amp seems to work fine but i didn't put it in the car yet.
i wonder why the chinese caps that i pulled out where all at the high side
eg 2200uf was 2300uf etc only 3-4 of them lost capacitance
happy new year everybody.
i install the amp back to car and the difference is tremendous.
guys the caps age but we are used to it because it happens very slow.
the bass is so tight and fast now that i would never imagine such a difference.
i have replace caps to the past with better but the difference is very small.
if i had an esr meter to measure the old caps esr i am sure i would find several caps
out of spec.
i install the amp back to car and the difference is tremendous.
guys the caps age but we are used to it because it happens very slow.
the bass is so tight and fast now that i would never imagine such a difference.
i have replace caps to the past with better but the difference is very small.
if i had an esr meter to measure the old caps esr i am sure i would find several caps
out of spec.
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