SEX change operation

audioengr · 5345

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Offline audioengr

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Reply #15 on: April 07, 2013, 08:22:10 AM
Okay, I have the C4S board and I'm ready to assemble and install it.  I have a question:

Is it critical to leave the board in one piece and connect the ground wire to the chassis lug 23L?

With my space constraints, I would rather split the board into two identical pieces and ground the boards at lug 22 and lug 13 respectively rather than both at lug 23.  It appears that using lug 23 causes this ground current to mostly run through the chassis rather than the wires.



Offline Grainger49

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Reply #16 on: April 07, 2013, 11:09:59 AM
I can't think that there would be a difference electrically.  As long as the boards are well grounded you should be fine.



Offline audioengr

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Reply #17 on: April 07, 2013, 11:18:59 AM
I think it is much more than just a ground.  There is current running from the current sources I believe.  If this is the case, then it should be better to ground it to the ground return wires for each tube circuit rather than the other chassis lug which is only connected to the other ground return wires through the chassis.  Currents through the chassis should be avoided IME.



Offline Paul Birkeland

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Reply #18 on: April 08, 2013, 12:34:31 PM
There is a tiny bit of biasing current through the C4S, but this is not signal current, and it is not in the signal current loop.

If you split the board into two pieces, you will have to mount two pieces in two places.  I would be much, much more concerned about a floating board grounding out the high voltage supply over anything else mentioned in this thread.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline audioengr

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Reply #19 on: April 08, 2013, 02:08:52 PM
There is a tiny bit of biasing current through the C4S, but this is not signal current, and it is not in the signal current loop.

If you split the board into two pieces, you will have to mount two pieces in two places.  I would be much, much more concerned about a floating board grounding out the high voltage supply over anything else mentioned in this thread.

I understand your concern.  I modded over 40 different manufacturers components from 2000-2009 and most of these components are still in use world-wide.  They don't short-out.  No worries.

For instance, one thing that I do is insulate all of those bare metal wires from the resistors and caps with Teflon tubing of different sizes.

Steve N.