Hello
i repair a punch amp 200.4 (4x25wrms)
the guy who have this amp before burn the mosfet in the supply and he modify the bias current
i find information to set the correct bias current here
Rockford Corporation Technical Library CD
but I do not know which way to turn the potentiometer to set it to the minimum before turn on the amp and procede to the bias set
is it in clockwise or counterclockwise ?
and what are the resistors to set the bias because i must put my multimeter on it to mesure 4 or 5 millivolt on each (rockford say that in the service manual)
I surrounded the resistors if you can confirm me if it is good please ?
I think the amp was build in 2000
Thanks for your help
i repair a punch amp 200.4 (4x25wrms)
the guy who have this amp before burn the mosfet in the supply and he modify the bias current
i find information to set the correct bias current here
Rockford Corporation Technical Library CD
but I do not know which way to turn the potentiometer to set it to the minimum before turn on the amp and procede to the bias set
is it in clockwise or counterclockwise ?
and what are the resistors to set the bias because i must put my multimeter on it to mesure 4 or 5 millivolt on each (rockford say that in the service manual)
I surrounded the resistors if you can confirm me if it is good please ?
An externally hosted image should be here but it was not working when we last tested it.
I think the amp was build in 2000
Thanks for your help
Turn them counter clockwise. I watch the idle current of the amp using a .005 ohm resistor in series with the amp B+ terminal. If you turn the pot slowly the idle current will increase quickly, then I back it off. You can find the knee at which the current takes off. I usually set it there and let it warm up and verify current doesn't increase.
Hello
Thanks brandes.cm
Yes the current increase quickly i move a little and the current increase...
i use a 12 volts supply with 5 Amp to set up the bias current i set up to 4.5mv on the 0.1ohms resistor and now the amp works fine and without heat
I mesure before adjust the bias and i have for channel front Left 17.5mv and 2mv for channel front right
for the rear channel i have 3mv and 18 mv
the guy who have this amp before me make nonsense
Now i run the amp in my car and works better
The bias was verry difficult to set 30 minutes to do because I am a perfectionist
Thanks brandes.cm
Yes the current increase quickly i move a little and the current increase...
i use a 12 volts supply with 5 Amp to set up the bias current i set up to 4.5mv on the 0.1ohms resistor and now the amp works fine and without heat
I mesure before adjust the bias and i have for channel front Left 17.5mv and 2mv for channel front right
for the rear channel i have 3mv and 18 mv
the guy who have this amp before me make nonsense
Now i run the amp in my car and works better
The bias was verry difficult to set 30 minutes to do because I am a perfectionist
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