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Bedrock amps: Need schematic also presence problem


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1/2/2000 5:09 PM
Joe Morgan
Bedrock amps: Need schematic also presence problem
I recently picked up a bedrock(no longer around) 50 watt el34 based 2x12. It has a pull pot on the master Vol and reverb. The presence control is not working. it makes a scratching noise when turned and has no effect on the signal. I thought that it was a bad pot, but it isn't then I checked the cap it too is fine.  
 
I would love to hear your thoughts as well as find a schematic for this thing.  
 
Thanks  
 
Joe
 
1/4/2000 12:43 AM
Carl Z

Personally I've never really heard any major differences whith the presence pot except at the more extreme settings. So I wouldn't sweat that too much. The scratchy sounds almost exactly like there's DC on the presence pot! Check your cap.  
 
Carl Z  
Summit Amps  
http://www.geocities.com/summitamps
 
1/4/2000 12:50 AM
Carl Z

Oh....one other thing. If your presence cap has gone completely shorted you won't have any presence control. It'll just pass everything straight to ground. Which would also explain a scratchy pot.  
 
Carl Z
 

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