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In the Forum: Audio Discussions
In the Thread: It’s mad, mad, mad... electricity.

Post Subject: FerritesPosted by JOHNR on: 12/1/2015

A clue!
You are not using the ground on the PP3000 unit and have ferrite packages on the incoming mains supply.

I am guessing that you have fitted a clamp directly around the power cord.

If this is the case, then you are using the ferrite on the ground conductor as well which is NOT good.

First off, a ferrite should never be used on the PE system. Why? Because it will act either as a ferrite that increases the impedance of the PE conductor which is NOT good OR, if the Q is correct, will absorb noise from the PE lead as intended BUT it may well transfer PE noise to the L and N conductors.

When using ferrites, one must consider the fact that if it manipulates noise, where does this noise go to?

Consider breaking into the power cord and retrieving the PE conductor to create an external loop for the L and N. Fit a clamp to the L and N only.

Never fit ferrites to ground wires unless you know the noise frequencies and also know the suitability of the ferrite device and how it responds to those frequencies. Peak up or absorb. They are not a broadband device as such.

Going back to the quoted Y network. Use 2000 volt rated Y capacitors, value 33nF, one per rail, join and using a single solid core wire e.g. Tefzel silver over copper to a convenient ground point.

John

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