American Bass CX-1200-D

[mike49504]

This amp is using RFP70N06's with 47 ohm gate resistors .

Is there a good sub for the RFP70N06's ?

[ian33]

irfz48 should work fine

[Perry Babin]

Since the RFP70N06s are readily available, I'm assuming that you want to use what you have on hand. Post what you have.

[mike49504]

Ill just order the originals from mouser .

Next question is The power supply in this amp was totally shot.

The outputs all test good . Does the class d board go bad if the power supply burnt up or generaly only if the outputs failed?

The class D board in this amp I believe is unrepairable if it goes bad.

[Perry Babin]

It's rare for driver boards to fail in most amps unless the transistors they're driving fail. You can install a couple of FETs to power it up to see if it produces clean output.

[mike49504]

Ok I replaced the power supply fets with the originals. Also replaced the drivers and gate resistors And a couple caps and a few other resistors in the supply.


If i try to power the amp up no light come on but i can hear the relay kick on.

Amp has 1.0 volts on leg 1 of the power supply fet and 13.5 on middle leg.

AMp does not produce rail or regulated voltage.

Wondering where i go from here?

[mike49504]

Ok i dont get this amp.

In the Pics there is a spot for a 47 ohm resistor right now i have it removed.

As soon as i apply power and ground no remote the resistor smokes within 1 sec

I pulled the driver boards for the power supply and it still smokes within a sec.

1 side of the resistor connects to a 47 uf 25 volts cap

the other side connects first to the 22 ohms resistor in the pic then goes to a diode which tests fine then goes to the relay.

If i measure across tthe pads of the 477 ohm resistor i get 13.92 volts on the pads.

Wondering what might cause this resistor to smoke within 1 sec?

[Perry Babin]

Photos didn't load.

[mike49504]

Duh

Heres the pics

[Perry Babin]

Are there any solder bridges?

Are any of the capacitors connected to the resistor shorted?