Orion 1200 D

[mike49504]

Wondering if anyone knows what gate resistors are used in this amp?

When i recieved it they were missing I know the amp use's IRF3205's for the power supply fets but not sure what vlaue gate resistors it takes.


Any help would greatly be appericated

[Perry Babin]

22 ohms

[mike49504]

Thanks,

Next question is there is 1 resistor missing also that connects to the 3rd leg of 1 power supply fet do you know the value on that also?

[Perry Babin]

If it connects between the source and the trace that feeds all of the gate resistors, it's a 1k.

[mike49504]

Ok i replaced the power supply fets,gate resistors, the drivers.

I took out the 3 driver boards in the output section.

Amp still draws excessive current .


Wondering what i check next? since i cant seem to find anything defective

[mike49504]

With a current limiter in line amp will power up and produce clean audio.

But the problem im having is 4 of the power supply fets get red hot within a sec or 2 .

Wondering what i should check at this point?

[Perry Babin]

Does the gate signal look identical for all of the FETs?

[mike49504]

.5 volts div 10us ??

[Perry Babin]

That's a good starting point. Adjust the timebase to get 3-4 complete cycles displayed.

[mike49504]

Heres what i get off the gate legs for the power supply fets . They all look this way