ampage
Tube Amps / Music Electronics
For current discussions, please visit Music Electronics Forum. New: view Recent Searches.
New: visit Schematic Hell!
The sunn still shines online!

 
Listen to great tunes streaming live right now!

ampage archive

Vintage threads from the first ten years

Search for:  Mode:  

Polarity to standby switch mod ?


 
4/9/2006 3:26 PM
Doug Lass
email
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
Watto
Try This  
 
https://weberspeakerscom.secure.powweb.com/store/5e3_layout.jpg  
 
Watto
 
4/9/2006 6:42 PM
Doug Lass
email

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
Mark
Doug,  
 
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
email

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
 
   Page 1 of 1