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Polarity to standby switch mod ?

4/9/2006 3:26 PM
Doug Lass
Polarity to standby switch mod ?
Has anyone figured out how to convert the polarity switch on a 5E3 to a Standby switch? A layout would be nice. I've already installed a grounded power cord and removed the cap off the polarity switch, ala Dave Funk's book. Thanks.
4/9/2006 5:37 PM
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4/9/2006 6:42 PM
Doug Lass

Thanks!. Something I noticed while comparing the Weber layout to the pics of Sean's(see homebrew homepage) chassis interior is... Sean's build has two wires off the standby switch as opposed to Webers three. Maybe I'm confusing the issue but my 5E3 is a '60 and I don't want to toast it. Doug
4/10/2006 5:21 PM
Polarity switches are SPDT. What you can do to wire it as a standby is to connect the common lug of the switch [ the one the cap was attatched to] to the first filter cap node and the output transformer center tap. Connect one of the other terminals of the switch to the rectifier [pin 8], and the remaining one to a grounded 10K/10watt resistor. When the stitch is in the standby, or non-play mode, the resistor bleeds the high B+ voltage to ground. This may prevent YOU from being toasted when you stick your hands in there.  
Good luck, and take good care of that amp.
4/10/2006 6:44 PM
Doug Lass

Thanks Mark. No, I don't need to be any more toasted than I already am. I will wire it up just as you suggest. Thank again, Doug
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