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 ?

 

[Hexhclass]

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?

 

[mike49504]

Ill replace both caps and see what happens.

 

[mike49504]

Replaced the cap still no luck.

I replaced the resistor with a 1/2 watt and that goes up in smoke also.

 

[mike49504]

Didnt notice it til now someone at one point removed the caps from the class D board.

Anyone know what value caps theese are?? the ones circled they are white

Also anyone know what relay goes in this amp since the cover to the one that in it is missing?

 

[Perry Babin]

I can't help on the capacitors.

The relays are generally a standard-layout 12v relay. When purchasing a replacement, order a SPST instead of a SPDT. The SPDT has an extra pin.

 

[Austin texans]

Mike did u get this amp to work??????