18w plexi layout - why 475V filter caps?

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Piamp
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18w plexi layout - why 475V filter caps?

Post by Piamp »

Hello,
i am building a 18W plexi following the 18w plexi layout.
I wonder why the 2 last filter caps are 475v : is it a typo ? 450v or even 400v should be enough here ?
thanks :)
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crgfrench
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Re: 18w plexi layout - why 475V filter caps?

Post by crgfrench »

That's probably just what was available for the can cap.
Like this one which is 500V: https://www.tubedepot.com/products/jj-c ... x-32f-500v
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Piamp
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Re: 18w plexi layout - why 475V filter caps?

Post by Piamp »

it's not a cap can, it's the axial cap for the first tube :)
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crgfrench
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Re: 18w plexi layout - why 475V filter caps?

Post by crgfrench »

Oh right I see that sorry I was looking at the FIRST 2 caps!
The layout is slightly different from the schematic.
In the schematic the 3 axials are spec'd at 450V (see image).
Probably whoever drew the layout just had some 475s on hand.
Either 450, 475 or 500V would be fine, NBD.
Screen Shot 2019-10-03 at 4.35.38 PM.png
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crgfrench
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Re: 18w plexi layout - why 475V filter caps?

Post by crgfrench »

For the axials I'd use either
https://tubedepot.com/products/sprague-atom-20uf-500v
or
https://tubedepot.com/products/f-and-t- ... -22uf-500v
it's fine to go to 22uF here, and the F&Ts are a lot less expensive than the Spragues.

For the can I'd go with the JJ.
https://tubedepot.com/products/jj-can-c ... x-32f-500v
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