Questions about PPI amp


Unregistered guest
I recently purchased a PPI PCX-1250 to power my dual 10" Infinity Perfects. I had them running off an old Kenwood amp, but that amp just didn't deliver enough power.

The speaker wiring is kind of confusing. There are two different places where it is indicated which terminal is for positive and which is for negative. The first is on the amp itself, and the other is on this removeable clip that snaps into the amp on one side while the speaker wires are screwed in on the other. On the amp, the order is like this: --R++ where the R is for the remote, or turn-on, wire. On the clip, the order is like this: -+R+-

Now, this is supposed to be a mono amp, so first of all, why are there two channels?

I followed the order -+R+- since that is also what the manual says. However, there was no sound output even though the power light on the amp was on.

I decided to try the other order --R++ and this produced sound for a little while, but then the 30A fuse near my battery blew and now it's too late at night to replace it and try again.

Here is a link to a pdf version of the owner's manual:

Some other information that might be useful to anyone who wants to help:
- the amp is refurbished, but i'm pretty confident that it's good because it was factory tested.
- I think my power/ground wire is only 10 gauge. Is this not big enough to power a 500W amp? Is a 30A fuse too small?
- In the short amount of time that I was able to listen to the amp, it didn't seem to be much more powerful than my old Kenwood amp that was pushing 100W to each speaker. This PPI amp should be doing 250W @ 2 Ohms (if I actually have it wired correctly). I would think there would be a noticeable difference.

Any suggestions?

Gold Member
Username: James1115

Wilton, Ct

Post Number: 2166
Registered: Dec-04
OK as far as the two speaker inputs it is because they give you the option to run two subs even though it is still running mono. Makes it easier on you! As for your fuse it is to small. to get the average fuse size you take the # of watts and divide by 12. 500/12=41 so would go with a 45 or 50 amp fuse. Thats also the reason it didnt sound like you were getting the amount of power you were supposed to bacause the amp produces more and more power as you turn the volume up. Put in a bigger fuse and you will see a big difference. Typically you look at the fuse size in the amp and use that size fuse to your battery.

Unregistered guest
So the two terminals are wired in parallel inside the amp? So if I connect 4Ohm subs, will the amp see it as a 2Ohm load? or do I need 2Ohm subs to have a 2Ohm load. The subs are single voice coil.

Gold Member
Username: Carguy

Post Number: 2226
Registered: Nov-04
If your subs are 4ohms SVC, then the amp will see 2ohms total.
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