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Some priorities!

Posted by grhughes on January 25, 2006 at 07:18:53

In Reply to: safest way of biasing an amplifier internally posted by afg on January 25, 2006 at 00:47:45:

1.First of all you need a dummy load to connect the amps output to (x2 for a stereo amp operated from one power supply). This can be a large 8 ohm resistor rated to the same power output as your amp. If it's rated to 100 watts then you need a 8 ohm, 100 watt wirewound resistor, but for most amps a 50 watt resistor will do (one for each channel). 2. You need a way of shorting the input/s to ground either with a RCA plug that its outer shell has been connected to the inner pin (2 for a stereo amp. 3. You need a reference voltage source like a 1 1/2 volt battery with a zener shunt as a calibration standard. This is to insure than the VOM is indeed reading what the appropriate bias is (it's voltage varies from amp to amp) 4. You need a good VOM (volt ohm meter by a reputable company; Fluke, Wavetek meterman, Simpson, Triplett) preferably with rubber armoured alligator clips or armoured hook grabbers (these are made by Pomona)5. You need detailed instructions by the maker of your amp to tell you what the recommended bias is and the biasing instructions. This can be had as as a Howard Sam's Photofact or directly from the manufacturer. Good luck! Ray
"I take you as you are
And make of you what I will,
Skunk-bear, carcajou, bloodthirsty
Non-survivor.
Lord, let me die but not die out." THE LAST WOLVERINE by James Dickey

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