Low impedance light flashing and amp clipping out?

Discussion in 'OT Technology' started by DNMonty, Sep 5, 2002.

  1. DNMonty

    DNMonty New Member

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    I have a PPI A600 amp I've been running for a year or so. Now out of nowhere I'm getting a problem with the amp when speakers are connected, the Low Impedance light starts flashing after a few minutes and it starts cutting out and then makes a popping sound, even @ very low volume.
    Tried this with either the car on (running off alternator) or off (strictly battery)
    Some background first though. About a month ago, I had to take the car in and they had to replace the throttle body since the computer they hook up to it wouldn't reset it properly. The need to reset it was (according to their determination) was because of a low voltage problem in the system and it's usually something they can just reset. But, they never looked into what was causing the low voltage problem. Scheduled to bring it in again today, since the idle is screwy again, figuring it's the same issue again.

    My question is......Could the amp be gettin freaky because of low voltage too? or is it likely smoked?
    I popped the fuse out of it for now, so I can @ least listen to the radio for now through the other low power amp (also a PPI, but only 50w total) I have another set of speakers @ home I can connect instead to rule them out, but I dunno if the throttle body thing and the amp problems are related syptoms of a bad voltage system or a cause effect thing. As in, could the amp draw enough to bury the car's electrical system and now it just doesn't have the juice to run it anymore? I've had more power than that in other cars without a problem and I've had this car since July 00 so it isn't that this is all new to it.

    Cliff notes on details of equipment:
    00 VW Passat 1.8t Auto
    PPI A600 150w/ch into 4 ohms running 2 Kicker C10a's
    PPI Sedona APA425 using 2 channels only to factory speakers
    4 guage power from battery
    4 guage ground in trunk
     
  2. flynfrog

    flynfrog Cool isnt Cheap

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    low voltage is hard on amps
    but it sounds more liek a cut speaker wire to me try the amp with no speaker wires attached and see what it does
     
  3. DNMonty

    DNMonty New Member

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    Tried that

    Tried with nothing connected and it's fine. But with no load, it would just have an open circuit and therefore wouldn't draw power. Tried the subs individually, and both did the same thing.

    The thing that leans me so much toward low voltage, is it seems to charge and discharge it's internal caps. Kinda like a rhythmic cycle, so I dunno what to think. I'm bringing the car in to the dealer with the amp's fuse out, so we'll see if the car's electrical stuff is the cause or the end result.
     
  4. flynfrog

    flynfrog Cool isnt Cheap

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    low voltage would casue the same problems have your electrical system checked out or you can do it yoru self see ow many votls your gettign to your amp
     
  5. DNMonty

    DNMonty New Member

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    Got the electrical system checked out, everything is fine with the car now. Computer adjustments fixed the engine stuff. Battery voltage has been fine according to it's logs. Alternator is fine too. I connected the subs individually and with either or both connected, it dies. I connected the subs to a home stereo, (4 ohm loads on a 8ohm stereo) worked fine. Pounded lotsa bass without issue for about 20 minutes. (figured long enough of a test to determine if the coils were bad.) Hooked up one sub to my PPI 4x25 as a 4 ohm load on 1 half of the amp bridged, giving it about 50w x 1, worked fine, but certainly quiet compared to the 150w x 2 I had.
    So I removed the A600 from the car, took the bottom off to inspect its innards and everything looked fine. The resistors and such a pretty big so I checked each one with an ohmmeter to verify their ratings, they all checked out fine. All components looked good, no burned part, popped capacitors or anything. I called a bunch of electronics repair places around and nobody will touch it since they do not have a schematic for it.
    So I contact www.precisionpower.net and check with their support guy and he refers me to Directed Electronics, the company that bought out PPI. They offered to have me send it in to them and would upgrade me to a new PPI PCX2200 for $549, I did a which search on the interweb and it sells online for $499. :wtf:
    I've actually been told by a couple places they would service it if I could get a schematic, but Directed won't give one to a consumer, only an authorized dealer. But they @ the HQ can't even repair it, so.....
    My only real option is to find a dealer that has been a dealer for a very long time and still owns the schematics and can work on it.
    The amp was only produced between 93 - 95, so fat chance of that. Any thoughts???
     
  6. flynfrog

    flynfrog Cool isnt Cheap

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    sounds like its time for a new amp
     
  7. DNMonty

    DNMonty New Member

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    Sent it to Tips Inc, in Mississippi and they repaired and tested it. $135 including shipping. Sent back on Friday and I should have by Thursday (UPS ground). I've been making CDs all week to "burn-in" the repaired amp.

    Anybody know if now that it's restored to rebiult condition if I should be able to connect 2 pairs of Kicker C10a's to it now? all 4 ohm subs. Want to hook up a pair to each side producing a 2 ohm load, but I don't wanna kill it. I think it might have been flaky for a long time, this was just the last puff of breath out of it. Now it should run like it's brand new.:x:
     
  8. flynfrog

    flynfrog Cool isnt Cheap

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    first off there is no such thinkg as burn in and i dotn knwo what the specs are on teh amp but if it is made to run at that low of an ohm load it shuld be fine
     
  9. DNMonty

    DNMonty New Member

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    What I meant by the "burn-in" was that if the repair was marginal, beating on it soon after getting it repaired should expose any weakness in the repair. (overheating, bad solder joints, etc) otherwise it could run marginally for a couple weeks and I end up with the same problem and they tell me it was my fault then. Pretty sure it's 2 ohm or lower stable, but it's been OOP for so long, I'm having a lot of trouble finding info on it now. I can't imagine 2 ohms beating it up too much, it is a PPI afterall, and older (before Directed bought them out) one @ that.
     
  10. DNMonty

    DNMonty New Member

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    OMG!!!!!! I got my amp back yesterday the rounded part on the top was scuffed!:mad: But I figured, eh it's only going in the trunk, I'll reserve my bitching if it doesn't work good.
    Hooked it up late last night in my garage. Tuned the settings to where they were before it left (actually remembered the levels) but didn't turn it on loud @ all. My garage is attached and it would've certainly woke the kids up. Turned it on to normal listening volume on the way to work this morning. Jeebus, this thing is a totally different amp than it was when it left. It's easily got twice the power I was pushing before. Screwed up my levels all over the place. It's got wayyyy more power now.
     

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