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Question about cathode bypass capacitor

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I am sorry if this has been already covered somewhere in the forum just couldnt find it during the quick search.
Is it OK to use one section of the power supply multi-section capacitor for cathode bypass or would it cause a problems?
If it's a bad idea, what type of separate capacitor would you recommend instead (except Black Gate) - some film cap like Solen metalized polyprop or just a decent electrolytic.

Thanks in ahead,

Argo
 
It's been done in the past. Unfortunately, they also sucked on the value, using for instance 20uF across a 250 ohm cathode bias resistor - what the heck good is that!

As long as the capacitance is sufficient and voltage rating in range, it's fine. (Caps like to be ran near rated voltage, otherwise they degrade and capacitance changes. This can be temporarily (i.e., <5 years) recovered by reforming. Using a 450V rated cap at 20V is not using your brain or resources.)

Tim
 
Thanks for the input.
I was thinking to use the free section of 220+220uF/500V Elna Cerafine PS cap. I didn’t thought about too high voltage rating though. Hmm, interesting point.
I was more worried about the common negative terminal of the multisection caps. As if one section will be used for PS smoothing and other section used for signal, probably both, very high and dirty currents and signal will flow through the same negative terminal tied to ground and will be mixed which could degrade the sound?
 
diyAudio Senior Member
Joined 2002
Hi,

Do you know the differences btw MKP,MKS and MKC?

Basically, in order of lower dielectric absorption:

1/ MKP 2/MKC 3/MKS

1/ Metallized polypropylene film
2/ polycarbonate (no longer manufatured, I think)
3/ polyester

You can find all the technical information here:

WIMA TECH PAPERS

Neither may be as good as the Audyn caps but for bypassing an electrolytic cap used as a cathode bypass the smaller size of the lower voltage caps is certainly more practical.

Cheers, ;)
 
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