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previous: Morgan I need to know if i am suspose to g... -- 12/11/2000 12:12 AM View Thread

Re: a couple more questions

12/11/2000 2:54 PM
Scott Swartz
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Re: a couple more questions
Yes, pin 9 will be grounded, and 4 & 5 to the 6.3 VDC.  
 
 
 
For the lowest hum you will want to use correct star ground practice, ie don't ground pin 9 to the chassis at the socket. The negative wire of the filament pair should connect to the junction of the filter cap and the bridge rectifier, then run a wire from that junction to the power supply star ground.  
 
 
 
Read up on star grounding if you're not sure what I'm talking about because correct grounding is very important in a tube pedal because of the low signal voltages.  
 
 
 
You may still get a hum from the third prong of the AC power cord, which can be eliminated by transformer coupling out of the pedal. This is a better solution than using a 3 to 2 prong adapter on the AC cord, which of course defeats the safety ground.