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Re: Is 220mA too Hot?


 
5/24/2000 1:28 AM
BILL R
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Re: Is 220mA too Hot?
Dan: when there is the possibility of something being "bad wrong" as they say around here, it is a good idea to do some "power off" testing with your meter after unplugging the amp and draining all the capacitors of their stored voltage. You can easily and safely check all your solder joints, see if your bias control is working, check ground connections, etc. using the ohm meter. By checking one component at a time in the circuits you changed, you also may notice an error in your work as you compare it to the schematic. Bill R.
 
5/24/2000 3:09 AM
jason
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quote:
"Also make sure your bias control is adjustable and not a 'bias balance' control. This could be your problem of not having the ma vary as you turn the pot."
 
the current should still vary as the pot is turned, he just can't set the bias to a desired current reading but only match the two sides, but he still should see the current vary when rotating the pot regardless. I'm sure you knew that Bob, just clarifing for Dan.  
 
jason
 
 
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5/24/2000 11:00 AM
Stephen Conner
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To save your output tubes, take them out while you are troubleshooting the bias circuit. They won't last long at 220 mA.  
 
Steve C.
 
5/24/2000 6:15 PM
Dan Z
Do I need a continuity test-tone on my meter to check solder connections or is there another way? The Radio Shack meter I have (~$40) doesn't have the test-tone. There are Flukes where I work that I could borrow for a night.  
 
Thanks again everyone.  
 
Dan Z
 
5/24/2000 6:20 PM
Ben
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Dan,  
 
You can just use your Ohm meter to test for continuity on the solder connections.  
 
 
Hope that helps  
 
Ben
 
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