Popping fuses!

flogger11 · Post by **flogger11** » Mon Aug 25, 2008 7:33 am

After wiring my ZPA to a 1 ohm bridged load, when I am REALLY HUMPING ON MY SUBS, at the limit, bass thumping HARD, I will blow my 80 amp fuse! WTF? I thought that was the most the amp would draw? I suppose I should put in a 100 amper? Opinions please...

Post by **fuzzysnuggleduck** » Mon Aug 25, 2008 7:37 am

Is your ZPA clipped? No, right?

It's possible however that you've got it just over the edge and the signal is clipping on the hard thumps and the current draw goes out the roof, blowing the fuse.

Post by **stipud** » Mon Aug 25, 2008 7:45 am

Maybe your "nib" ZPA has already had the mod done to it

It'd be worth checking, at least...

Post by **Jacampb2** » Mon Aug 25, 2008 7:46 am

If the power supply mod was done, then it will draw significantly more current then it used to into low impedance loads. It could easily double it's full output power current draw if it can't switch into high current mode.

Later,
Jason

flogger11 · Post by **flogger11** » Mon Aug 25, 2008 8:11 am

It was for sure NIB, Tristen wouldnt play that game. also no mod done, checked. I probably was at the edge, clipping the amp a touch. Maybe because I have 4 volts to the PLD-1, then that set WFO, the amp can see upwards of 11-12 volts input, causing the overdrive. That it you guys think?

gkitching · Post by **gkitching** » Tue Aug 26, 2008 6:12 am

The pld will only output 8 volts. Not add 8 volts to the input voltage.

Post by **stipud** » Tue Aug 26, 2008 6:58 am

If you're seeing 11 volts out of the PLD, you are probably clipping the signal before it gets to your ZPA. Turn your PLD gains down to ~8v, and make sure the clip light isn't flashing... otherwise drop it further.

mmmadog · Post by **mmmadog** » Tue Aug 26, 2008 12:04 pm

It blows at 80 amps to protect your amp. At 1 ohm that thing is drawing a serious amount of power. With musical peaks its well above 80 amps. If you can try it at 4 ohms and adjust your gains. That thing should play very loud and clean wih lots of headroom............Matthew

Post by **Bfowler** » Tue Aug 26, 2008 12:09 pm

^he was running it at 4ohms with no problems before....but couldnt resist the 1ohm temptation. he said there was a noicable difference at 1ohm so he he is looking to reduce his input voltage justa bit and swap to a higher rated fuse

mmmadog · Post by **mmmadog** » Tue Aug 26, 2008 12:24 pm

I wouldnt run any amp at 1 ohm. Might make more power but it makes more distortion more clipping and less damping factor. Plus way more current and heat. If it was suppose to have a 100 amp fuse it would have came with one. I guess when they say they play at 1 ohm they sell more amps.

Zarnov · Post by **Zarnov** » Tue Aug 26, 2008 12:31 pm

I ran a ZPA0.5 to two 12's (1.8ohm bridged) and tripped a 100A circuit breaker (hit 141db before it tripped too!!), so 80A draw doesn't really seem out of line to me

flogger11 · Post by **flogger11** » Tue Aug 26, 2008 12:34 pm

mmmadog wrote:I wouldnt run any amp at 1 ohm. Might make more power but it makes more distortion more clipping and less damping factor. Plus way more current and heat. If it was suppose to have a 100 amp fuse it would have came with one. I guess when they say they play at 1 ohm they sell more amps.

The ZPA is the exception to this GENERAL rule. These subs sound twice as good w/ the one ohm load. I no longer have a fuse problem as I have had to make some adjustments (in my head) on having 10's instead of 12's (this is my first set of 10's and I love 'em!).

Zarnov · Post by **Zarnov** » Tue Aug 26, 2008 12:37 pm

flogger11 wrote:
mmmadog wrote:I wouldnt run any amp at 1 ohm. Might make more power but it makes more distortion more clipping and less damping factor. Plus way more current and heat. If it was suppose to have a 100 amp fuse it would have came with one. I guess when they say they play at 1 ohm they sell more amps.
The ZPA is the exception to this GENERAL rule. These subs sound twice as good w/ the one ohm load. I no longer have a fuse problem as I have had to make some adjustments (in my head) on having 10's instead of 12's (this is my first set of 10's and I love 'em!).

Yup...the ZPA are a beast unlike many others

flogger11 · Post by **flogger11** » Thu Aug 28, 2008 3:43 pm

I havent popped a fuse in days, that is until coming home late last night after an unsuccesful night of chasing putang. I was wailing away, when WHAM! no output from my subbies. Whats weird is the fuse didnt even blow, it looks perfect! WTF? I replaced it with a new fuse on a whim and the amp works like a charm. I have never had this happen before, I thought it was an urban myth! LOL!

Post by **stipud** » Thu Aug 28, 2008 5:45 pm

I've had fuses "invisibly" fail as well. Haven't had that problem since I switched to ANL. Actually, I haven't had a single failure since then...

Post by **fuzzysnuggleduck** » Thu Aug 28, 2008 6:36 pm

Yeah, I've seen some "blade type" fuses fail invisibly. Also some old school home GP15 (screw in, like a light bulb) fuses.

Post by **smgreen20** » Fri Aug 29, 2008 2:41 am

Tests have shown that the ZPA amps actually drop in power output when you go into 2, 1 ohm loads when the amp switches modes. The result I read in CSR about 10 yrs ago a 0.5 was doing 1115 @ 4 ohms, but dropped to 796 (or so, can't remember the actual numbers) @ 2 ohms. So it would benifit you and the amp to run at 4 ohms.

As for the fuses, ANL is the way to go, though I'm not to keen on ANL SEKS

. The solder joints get hot and melt loosing/breaking contact.

flogger11 · Post by **flogger11** » Fri Aug 29, 2008 4:50 am

smgreen20 wrote:Tests have shown that the ZPA amps actually drop in power output when you go into 2, 1 ohm loads when the amp switches modes. The result I read in CSR about 10 yrs ago a 0.5 was doing 1115 @ 4 ohms, but dropped to 796 (or so, can't remember the actual numbers) @ 2 ohms. So it would benifit you and the amp to run at 4 ohms.

As for the fuses, ANL is the way to go, though I'm not to keen on ANL SEKS . The solder joints get hot and melt loosing/breaking contact.

WRONG!!! The ZPA produces as much, if not more power, into a 1 ohm load vs a 4 ohm! Yes, the 2 ohm rating sucks, but not the 1 ohm. This is because at 2 ohms the amp switches from high voltage to high current mode, thus enabeling a 1 ohm bridged mono load. The problem is when you run 2 ohms bridged the amp isnt loaded up like at a 4 ohm high voltage load or a 1 ohm high current load, hence the lower power output at 2 ohms. However, when loaded up correctly, this baby is a 1 ohm stable, knock you in the face power monster! Above and beyond the technical facts, my ears tell the truth, MORE POWER AT 1 OHM VS 4 OHMS, GUARANTEED!!! (I am revved up today! LOL!)

Post by **smgreen20** » Fri Aug 29, 2008 7:46 pm

No...I'm still right. That circuitry that's in there still holds true when in that mode. regardless of weather it's 2 ohms or 1. It still goes up, but not by much. The ZPA0.3 I'm selling was benched. What the numbers where I don't recall anymore but before the mod at 1 ohm it was still in the mid 500 wrms range when at 4 ohms it was in the upper 600s (680s IIRC).

After the mod at 2 ohms it was in the upper 800s (870s?) All at a 14v input.

I stand firm on my post (s) because I was there and did that. I know you're not calling me out or anything, but I wont post if I don't know. I'm not about misinformation.