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View Full Version : Grounding reminder pls


The Captain
08-20-2007, 03:55 PM
Hi there, can someone remind me where to ground these 3 please? (Princeton AA964 clone fwiw):

1. Power Transformer primary green/ yellow (not a secondary CT).
2. from pins 8 of two 6v6s (linked as one).
3. pair of 100rs as a filament CT from the pilot lamp.

Thanks alot, Captain.

The Captain
08-21-2007, 12:50 PM
Can no-one help me out here?

Tubenit
08-21-2007, 01:32 PM
I use this one:

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

Looking at this schematic and layout:

http://www.schematicheaven.com/fenderamps/princeton_aa964_schem.pdf

my guess is your grn/yel is the center tap for the 6.3v which you would not use if you use 100ohm resistors for an artificial center tap.

With respect, Tubenit

stokes
08-21-2007, 01:58 PM
Cap'n,those are all what I consider "high current" grounds,and should be connected together near or to the PT bolts,along with the grounds for the main and screen filter caps.I gotta question that green/yellow PT primary you describe,it sounds like the 6.3v CT,and like Tubenit says,shouldnt be used if you use the 100ohm pair on the heaters.

The Captain
08-22-2007, 12:50 AM
Thanks chaps, Mr Stokes again its defo not a CT- its an earth on the primary side of the PT. I seem to recall I may have attatched it with just the mains cable earth to 'bttm left corner' PT bolt when I used it before- but I just can't remember!?

here it is: http://www.torresamps.com/images/trans-25.gif

stokes
08-23-2007, 01:53 AM
Thats a shielding for the PT,I would connect it as you describe,along with the mains ground,or along with what I referred to as the "high current" component grounds.