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presence has bad attitude

4/29/2005 2:32 AM
presence has bad attitude
With a Marshall style PI and a Post PI MV I'm getting a constant light clipping, slightly low volts around the PI and the presence circuit is adding a squeek at high settings. Swap PI leads? New EH EL34s/12AT7 PI and Eminence Swamp Things.  
May just try an Ampeg style PI.
4/29/2005 1:43 PM

Seems to be a parasitic oscillation phenomen around the PI. Sometimes this occurs, when you're placing the post PI MV on to the rear panel next to the power tubes.  
Try to twist the two wires running to your MV.
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