How To: Power 2 Amplifiers With A M2-ATX

**Maheriano** · 09-26-2009, 05:04 PM

I have a Rockford Fosgate Punch P300.1 amplifier for my subwoofer and it requires a higher power input on the remote line than the M2-ATX can provide so here's how you can solve this if you're having similar issues.

Tools you will need (maybe):

A computer to read this DIY

Soldering iron

NPN Type Switching Transistors

Wire stripper

solder

lighter

heat shrink tubing

random lengths of wire

refreshments

What To Do:

Take out one of the transistors and bend the pins out so they're easier to work with:

Connect some lengths of wire in a Y shape to branch off and connect to both amplifiers:

Solder the wires together:

Cut off a piece of heat shrink:

Solder it to the transistor along with a power wire. The placement of the wires is detailed on the back of the packaging for the transistors:

Heat up the heat shrink so it shrinks around the wiring and seals it up:

solder on the final wire in the car:

Now when you turn on the computer it should power both amplifiers as well. Enjoy!

**barnyard** · 09-26-2009, 05:34 PM

Nice how-to, but you really should include some detail as to what goes where!

**Maheriano** · 09-27-2009, 12:44 AM

There are 3 pins coming off the transistor, they go to the battery, 1 to the amplifiers and 1 to the J6 connector on the M2-ATX. The diagram on the back of the transistor packaging will actually show you which wire is for what, I won't post it here because it might differ between transistors. It's really rather simple, there's not much to say.

EDIT - I'll explain it briefly here.
The pins are numbered and the numbered diagram is on the back of the packaging. But one pin is labeled as COLLECTOR and that will take the input from the power supply. In my case it's the J6 connector on the M2-ATX. Another pin is labeled BASE, this is power from the battery of the car. The last pin is labeled EMITTER, this sends the power out to the amplifiers, split the wire and run it to each amplifier. Done.

**crankycowboy** · 04-23-2010, 01:23 PM

Maheriano,

It didn't work for me, actually I have the base connected to car battery, collector to the J6 + pin on the M2, and the emitter out to the amps. I can test that I have 12v at j6, but the emitter line shows 0 voltage. I used the exact transitor package you had listed in your pictures....however, that package comes with 15 transistors (5 ea of three different types). The one I used was the 2n4401052.....should I have used one of the others? There is a 2n3901331 and a 2n2222a338 also. Seems simple...but not working properly. Please advise!!

**Curiosity** · 04-23-2010, 01:35 PM

The collector should be connected to the supply (battery) and base to the switch (amp remote on PSU). Any of those transistors will work. For lower current drain on the PSU, a 1K resistor should be placed between the base and PSU.

**crankycowboy** · 04-23-2010, 05:16 PM

Thanks Curiosity....that contradicts what Maheriano said above. I tried it the way you suggested, and it didn't turn my amps on either; however, I think the transitor may be bad....going to try another one. Thanks for your help!

**crankycowboy** · 04-23-2010, 06:24 PM

Originally Posted by crankycowboy

Thanks Curiosity....that contradicts what Maheriano said above. I tried it the way you suggested, and it didn't turn my amps on either; however, I think the transitor may be bad....going to try another one. Thanks for your help!

I replaced the transistor with a new one....I guess I am doing something wrong. Before, when I would connect my remote out on the M2ATX to a "load" it would drop from 12 volts down to about 3 and the amps wouldn't turn on. When I connected it as curiosity suggested (collector to battery, base to PSU amp out) and emitter to amps, I have even less voltage on the leg going to the amps now (around 1.2 volts). Any suggestions? Geez!!

**Curiosity** · 04-23-2010, 06:38 PM

What's the voltage on the gate? The 2N2222 would be a good one since it's around 500mA collector current which should be more than enough. The gate may be pulling too much though. If it drops the voltage, you'll need a resistor. I'm sure 1K would work well in most situations.

**crankycowboy** · 04-23-2010, 09:07 PM

Originally Posted by Curiosity

What's the voltage on the gate? The 2N2222 would be a good one since it's around 500mA collector current which should be more than enough. The gate may be pulling too much though. If it drops the voltage, you'll need a resistor. I'm sure 1K would work well in most situations.

Curiosity, I really appreciate all your time. Now, can you please put it in laymans (dumb a$$) terms? Where do I measure at the "gate"? I'll try the 2n2222 tomorrow. Where do I put the resistor and doesn't it matter on them which way the lines are facing? Sorry for all the dumb questions.....

**Curiosity** · 04-23-2010, 11:47 PM

Oops, sorry I'm senile.

I meant base. Gate is a MOSFET term but basically works the same. But anyway, check the volts on the base. The resistor can be either direction. Just solder one end to the base on the transistor and the other to the wire going to the J6 connector.