How to ground filter caps in cap pan?

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theundeadelvis
Posts: 55
Joined: Mon Oct 22, 2007 11:30 pm

How to ground filter caps in cap pan?

Post by theundeadelvis »

I'm finishing a AB763 Deluxe Reverb build, and was wondering what the best method for grounding the filter caps is? They are on their own board on the outside of the chassis in a cap pan. Should I just ground them near the pan, or run wires into the chassis and ground them with power tubes, bias board, and PT? Thanks in advance!
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Structo
Posts: 15446
Joined: Wed Oct 17, 2007 1:01 am
Location: Oregon

Re: How to ground filter caps in cap pan?

Post by Structo »

I have read that the main power supply filters are best grounded near the PT.
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LOUDthud
Posts: 464
Joined: Tue Sep 25, 2007 9:27 pm
Location: Texas

Re: How to ground filter caps in cap pan?

Post by LOUDthud »

It's best to separate the plate and screen ground from the preamp filter ground. A bad buzz usually results otherwise.
ampgeek
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Joined: Sun Oct 15, 2006 1:31 am

Re: How to ground filter caps in cap pan?

Post by ampgeek »

Take a look here for the Hoffman preferred method:

http://www.el34world.com/charts/filtercaps.htm

The example shown is for a 5F6A plan but the concept should be applicable to your situation.

Theoretically, (and as LThud alludes) the optimum is to ground the filter cap(s) at the location of the cathode ground for the section that it is filtering. However, some plans are much less sensitive than others.

Good luck,
Dave O.
theundeadelvis
Posts: 55
Joined: Mon Oct 22, 2007 11:30 pm

Re: How to ground filter caps in cap pan?

Post by theundeadelvis »

Thanks!!
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