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ZPA .5 and .3 wattage?

Posted: Sun Jul 06, 2008 7:01 pm
by SkierMan
What are these amps rated at 4ohm, 14.4v? I am attempting to purchase these amps but after some time of searching I have come across many different ratings for these amps. Ive seen 150x2, 250x2, 300x2 for the ZPA .5 and 75x2 to 150x2 for the .3 What is the correct RMS for these amps?

Re: ZPA .5 and .3 wattage?

Posted: Sun Jul 06, 2008 7:27 pm
by flogger11
SkierMan wrote:What are these amps rated at 4ohm, 14.4v? I am attempting to purchase these amps but after some time of searching I have come across many different ratings for these amps. Ive seen 150x2, 250x2, 300x2 for the ZPA .5 and 75x2 to 150x2 for the .3 What is the correct RMS for these amps?
I have the ZPA manual in my hand, power is as follows:

Output Power per Channel (both channels driven)

ZPA0.5:
Into 4 or 1 ohm @ 12/13.8 VDC.................150/300 Wrms
Into 2 or .5 ohms @ 13.8 VDC...................500 Wrms
Bridged into 4 or 1 ohm @ 13.8 VDC..........1000 Wrms

ZPA0.3
Into 4 or 1 ohm @ 12/13.8 VDC.................75/150 Wrms
Into 2 or .5 ohms @ 13.8 VDC...................250 Wrms
Bridged into 4 or 1 ohm @ 13.8 VDC..........500 Wrms

Remember, these ARE conservative numbers matched against anything made today, however to meet the power demands of these monsters you have to have a very strong charging system along with an 8 volt linedriver...

Good luck dude, I am about to try my first ZPA, a 0.5! It will be here Friday and I cant wait!

Posted: Sun Jul 06, 2008 7:29 pm
by SkierMan
Ok, cool. Anyone have birth sheets or measured what they actually do?

Posted: Tue Jul 08, 2008 2:33 pm
by smgreen20
Real world, I have both, only the 0.3 has been benched. The 0.3 also has the "MOD" done.

But at 2 ohms mono it did 872 wrms at 14v

Note that's 14v not 14.4v

It's rater to do 600 X 1 @ 2 ohms, that's a 45% increase in power so you might expect to see the same out of the 0.5, remember that was WITH the mod done, so that would translate to 1,450 wrms X 1 @ 2 ohms

I do recall seeing on another forum a few years back that a 0.5 moded did almost 1600 wrms, but perameters weren't given. In a review that CSR did, it pushed out 1107 wrms at 14v X 1 @ 4 ohms.

Oh yea, the manual you have is a V1 manual, the V2s have the 0.3 at 600 X 1 @ 2-4 ohms

Posted: Tue Jul 08, 2008 2:44 pm
by SkierMan
Is there a benefit of doing the mod for a 4ohm speaker? Meaning, will the ZPA operate at a 2ohm load with the mod even though the speaker is 4 ohm?

Posted: Tue Jul 08, 2008 4:39 pm
by smgreen20
No, ohms law still applies.

The amp has a circuit that theoreticly lets it output the same wattage from 2-4 ohms, but you can bypass that and have more output at 2 ohms olike normal.

Posted: Sat Jul 12, 2008 1:56 pm
by SkierMan
What will a 0.3 run at 6 or 8 ohm per channel then?

Posted: Sat Jul 12, 2008 3:47 pm
by Jacampb2
SkierMan wrote:What will a 0.3 run at 6 or 8 ohm per channel then?
Cooler. LOL.

Realistically at 8 ohms it should run roughly half the output power of 4 ohms. The amp protection circuitry that can be modded, forces the amplifiers power supply to reduce rail voltage when driven into a very low impedance load. This basically forces the amp to make the same power into 1 through 4 ohm loads. Normal calculations should still hold true for any load that falls above the given range.

As for 1600Wrms into 1ohm. It is kind of like over clocking a CPU. It can do it for a while. A modded 0.5 will pull it off, but not for long. If it is a competition only thing, then they would probably (maybe) survive a while. If it is a daily 45 minute bass head thing, it will end in expensive flames.

Good Luck,
Jason

Posted: Mon Jul 14, 2008 3:35 pm
by smgreen20
The 1600 was at 2 ohms, not 1 ohm. If you do the mod to either one of the amps, you CAN NOT go lower then 2 ohms mono or she'll fry.

Posted: Tue Jul 15, 2008 10:02 am
by Tone
I run a 0.5 to a pair of DVC 12" subs in stereo @ 4 ohms per side and they are chest poundingly loud, tight and deep. I also run a 0.3 to my front end with a set of 6.5 Focal KP2s and 5.5 ADS midbasses in parallel so the amp sees only 2 ohms. The 0.3 would switch into protective current handling when played at higher volumes so I performed the MOD and now it works perfectly.

Posted: Thu Jul 17, 2008 5:10 am
by denim
I would love to find some ZPA's for a decent price.