Hello everyone, I'm new to this forum because I've recently had some problems with my amplifier (I'm assuming it's the amplifier) and I've been searching around this forum for some answers. I can't seem to find any other threads with a problem quite like mine.
I have a PPI PCX-4125 amp and recently I've had static in all 4 speakers that is the same loudness at all volume levels, and it's somewhat random, usually when first turning the amp on. It seems to calm down after the amp warms up a bit. The other problem that started at the same time was a loud pop from my rear speakers when I turned the amp off.
Does anyone have any ideas where I can start looking to fix these problems? I'm a recent electrical engineering graduate so I have a basic understanding of most electronics, I just don't know much about amplifiers and without a schematic I don't know where to start looking.
I've taken the amp apart and checked for cold solder joints and any obviously burned parts and can't seem to find anything obviously wrong with it.
Any help would be greatly appreciated!
Thanks.
--Mike
I have a PPI PCX-4125 amp and recently I've had static in all 4 speakers that is the same loudness at all volume levels, and it's somewhat random, usually when first turning the amp on. It seems to calm down after the amp warms up a bit. The other problem that started at the same time was a loud pop from my rear speakers when I turned the amp off.
Does anyone have any ideas where I can start looking to fix these problems? I'm a recent electrical engineering graduate so I have a basic understanding of most electronics, I just don't know much about amplifiers and without a schematic I don't know where to start looking.
I've taken the amp apart and checked for cold solder joints and any obviously burned parts and can't seem to find anything obviously wrong with it.
Any help would be greatly appreciated!
Thanks.
--Mike
Sounds like one or more of your speakers' terminals is touching ground somehow. Maybe one of the rear? Are any of your speakers made by kicker? They had a problem with internally shorting to their frames and causing issues like that. It could also be a lack of ground connection of the rca jacks at the deck side (inside the deck, maybe a burned or cracled rca ground trace)
I am running MB Quart PCE-216's in the rear and QSD-216's in the front, I forgot to mention that I have recently blown one of the front speakers I believe with a combination of loud rock music and poor tuning on my part. I found out the hard way that these two speakers sound so drastically different that it is VERY difficult to tune them and actually make them sound good with one general EQ for both sets of speakers. I don't know when this happened, but it could have happened around the same time this problem started, I haven't taken the door apart to look at it yet. Another set of PCE-216's will be replacing the blown Q's up front in my near future.
Speaker terminal grounding was the fist thing I checked when this all started. Although I just simply checked for continuity between the speaker wires (@ amp terminals) and ground when I did it. I will dig in a little more this time and I'll post back to let you know what I find.
Thanks for taking the time to respond!
Speaker terminal grounding was the fist thing I checked when this all started. Although I just simply checked for continuity between the speaker wires (@ amp terminals) and ground when I did it. I will dig in a little more this time and I'll post back to let you know what I find.
Thanks for taking the time to respond!
If you have 12dB/oct crossovers and have an open speaker, that can cause problems for some amps. At the crossover point, the impedance is near 0 ohms when there is no speaker load on the crossover.
When troubleshooting a problem like this, you should disconnect all speaker wires from the terminal block of the amp and test the amp with a known good speaker and a short length of speaker wire (that's run directly from the amp to the speaker).
When troubleshooting a problem like this, you should disconnect all speaker wires from the terminal block of the amp and test the amp with a known good speaker and a short length of speaker wire (that's run directly from the amp to the speaker).
Ok, I checked the grounds today and everything seems fine. I also checked the impedence of all my speakers and they are all 4 ohms.
I checked between the RCAs on the amp and the chasis ground and there is (I can't remember exactly) but somewhere between 9 and 14 ohms there.
There is about 1.5 ohms between the RCA ground on the head unit and the chasis ground. (Checked at the end of the RCA cables in the trunk, not right at the head unit.)
I also tried a known good speaker and switched the input to another source using different RCA cables and the static noise is still there. In fact, the static is there even with no source plugged in and just one speaker (known good one) plugged in.
The part that throws me is how random the noise is, it is the worst when the amp is first turned on, it gets better as it warms up. It goes away for a while but will always come back at random times while the amp is running.
The times when the noise is at its worst, is usually after running the amp hard and then turning it down, or running it hard and then shutting it off, when you turn it back on you will be greated with an earfull of static.
If it would help out, I could record the noise it makes and post a link to a .wav file for people to listen to it. It sounds pretty strange to me.
Thanks again for the help everyone, I really appreciate everyone taking time to read all of this and give me advice.
I checked between the RCAs on the amp and the chasis ground and there is (I can't remember exactly) but somewhere between 9 and 14 ohms there.
There is about 1.5 ohms between the RCA ground on the head unit and the chasis ground. (Checked at the end of the RCA cables in the trunk, not right at the head unit.)
I also tried a known good speaker and switched the input to another source using different RCA cables and the static noise is still there. In fact, the static is there even with no source plugged in and just one speaker (known good one) plugged in.
The part that throws me is how random the noise is, it is the worst when the amp is first turned on, it gets better as it warms up. It goes away for a while but will always come back at random times while the amp is running.
The times when the noise is at its worst, is usually after running the amp hard and then turning it down, or running it hard and then shutting it off, when you turn it back on you will be greated with an earfull of static.
If it would help out, I could record the noise it makes and post a link to a .wav file for people to listen to it. It sounds pretty strange to me.
Thanks again for the help everyone, I really appreciate everyone taking time to read all of this and give me advice.
Any other ideas on this problem? Is there anything other than a ground short that would cause this problem? If not, what about the loud pop I get every time I power down the amplifier? These two problems started at the same time so there has to be some common problem causing them both.
The amp has the same problems on a bench with all known good components hooked up so I know the problem is in the amp. My next step is to completely dissassemble the amp and check for any components that look discolored and try replacing them. I have no idea what can cause these symtptoms but if I find anything obvious I will post on here what I find just in case someone else has a similar problem.
The amp has the same problems on a bench with all known good components hooked up so I know the problem is in the amp. My next step is to completely dissassemble the amp and check for any components that look discolored and try replacing them. I have no idea what can cause these symtptoms but if I find anything obvious I will post on here what I find just in case someone else has a similar problem.
possibly bad solder joints on the board somewhere, or bad caps. Can you remove the board and have it reflowed in a electronics rated reflow oven somewhere local. Should only take 5 minutes to reflow and 1 hour cool down.
On a easier note try a heat source like a small blow dryer, and or some freeze spray on the amp in small areas looking for the fault....
On a easier note try a heat source like a small blow dryer, and or some freeze spray on the amp in small areas looking for the fault....
I have not yet solved this problem, I usually just turn it up until the music covers up the noise. It's getting worse now that it's summer though, it seems to get worse with heat.
I think sometime in the future I will take it apart and do some messing around with it, I'll post back here if I end up finding a solution. It may be a few weeks though before I get around to it. It all depends on how annoyed I get with the noise.
I think sometime in the future I will take it apart and do some messing around with it, I'll post back here if I end up finding a solution. It may be a few weeks though before I get around to it. It all depends on how annoyed I get with the noise.
The amp making the popping noises would be classed as normal for me.
I use an old McGregor in my room, and that (from what I can tell) empties it's capacitors into the speaker when it's switched off.
But when I switch it off, it comes out more of a thud, except with smaller drivers (must depend on resonance).
When the amp is just sat there, switched on, does it get really hot???
Could it be possible, that you've blown the amp?
I use an old McGregor in my room, and that (from what I can tell) empties it's capacitors into the speaker when it's switched off.
But when I switch it off, it comes out more of a thud, except with smaller drivers (must depend on resonance).
When the amp is just sat there, switched on, does it get really hot???
Could it be possible, that you've blown the amp?
I think I might be able to help with this problem. But first there are a few things that I need to know. How many amps are you running? What size fuse does each amp your running have in it? Are you using a single or multi cap set up? If your not using any caps, are you using a multi battery set up? What gauge power wire are you using? How far away from the engine battery is your inline fuse? And last, what size inline fuse are you using?
Sorry about all the questions. But in order for me to assist you, I really need to have an understanding of what I'm working with. I had this same problem with a 96' Camero that I designed and built for SPL competition. It took me about six or seven days to go through the whole system and trouble shoot it.
So get back to me with the answers for all those questions and I'll see what I can do.
Sorry about all the questions. But in order for me to assist you, I really need to have an understanding of what I'm working with. I had this same problem with a 96' Camero that I designed and built for SPL competition. It took me about six or seven days to go through the whole system and trouble shoot it.
So get back to me with the answers for all those questions and I'll see what I can do.
A delayed response...
Sorry it took me a while to post this, but here is some more information on my setup.
I am running two amps. a PCX-4125 and PCX-1500. Each one is rated 1000 Watts RMS @ 12V (with a 2 ohm load), which technically gives you around 83 amps draw per amplifier. I am running the 4 channel with 4 ohm loads, and the mono with a 2 ohm load so that brings me to about 125A draw. I have 1/0 wire running from the battery (main car batter) to the trunk, where it hits a 3 or 4 farad capacitor (I can't remember exactly) then it hits a terminal block where goes to 4 gauge wire to each amplifier (I am pretty sure, but would have to double check the wire, I installed it a year or 2 ago). I have an inline circuit breaker rated at 150A about a foot from the battery.
I cannot remember what fuses are in the amps right now, I would have to double check that and get back to you, they are whatever I got with the amps.
The speaker wire is I think 14AWG, and the RCAs were the expensive ones, ZN6 or ZN9 from streetwires... I can't remember.
Sorry it took me a while to post this, but here is some more information on my setup.
I am running two amps. a PCX-4125 and PCX-1500. Each one is rated 1000 Watts RMS @ 12V (with a 2 ohm load), which technically gives you around 83 amps draw per amplifier. I am running the 4 channel with 4 ohm loads, and the mono with a 2 ohm load so that brings me to about 125A draw. I have 1/0 wire running from the battery (main car batter) to the trunk, where it hits a 3 or 4 farad capacitor (I can't remember exactly) then it hits a terminal block where goes to 4 gauge wire to each amplifier (I am pretty sure, but would have to double check the wire, I installed it a year or 2 ago). I have an inline circuit breaker rated at 150A about a foot from the battery.
I cannot remember what fuses are in the amps right now, I would have to double check that and get back to you, they are whatever I got with the amps.
The speaker wire is I think 14AWG, and the RCAs were the expensive ones, ZN6 or ZN9 from streetwires... I can't remember.
This time its me who's sorry for taking so long to reply. I've been pretty busy lately. Anyways, the first issue I want to discuss is the terminal block that you spoke of. I'm not sure if you are talking about a standard power distrubution block or a multi fused distrubution block. Either way, the one you will be needing to have installed is the fused distrubution block. If you are running 4 gauge out of the block and into each amplifier. I would suggest you use fuses rated between 20 and 25 amps(I) above each amplifiers original/stock fuse rating.
Also you will need to have a standard ground distrubution block. Make sure you use the same gauge wire for all grounds that you are using for power. The main ground should be from the vehicle chassis to the input side of the ground block. Then a second ground wire will connect the secondary power supplies ground terminal to the input side of the ground block.
Next I would reccommend increasing the 150 amp(I) breaker you have installed to one that has anywhere from a min rating of 180 amps(I) a max rating of 250 amps(I). Also installing a high current (250 amp(I) max rated) ignition relay between the engine battery and the breaker is somthing I also reccommend doing.
This will reasure that the vehicles start up battery will remain isolated from any power drain connected to the secondary power source, inless power has been given to the vehicles ignition.
Try all of the things I just explained if they are not already present in the system. I'm almost positive it will cure the problem you've been having. If you try all that I have suggested and the problem persists, the next step will be to trouble shoot the amplifiers and headunit. This will determine if the problem is being caused from the power side or the sound side. Let me know how it goes and we can go from there.
Also you will need to have a standard ground distrubution block. Make sure you use the same gauge wire for all grounds that you are using for power. The main ground should be from the vehicle chassis to the input side of the ground block. Then a second ground wire will connect the secondary power supplies ground terminal to the input side of the ground block.
Next I would reccommend increasing the 150 amp(I) breaker you have installed to one that has anywhere from a min rating of 180 amps(I) a max rating of 250 amps(I). Also installing a high current (250 amp(I) max rated) ignition relay between the engine battery and the breaker is somthing I also reccommend doing.
This will reasure that the vehicles start up battery will remain isolated from any power drain connected to the secondary power source, inless power has been given to the vehicles ignition.
Try all of the things I just explained if they are not already present in the system. I'm almost positive it will cure the problem you've been having. If you try all that I have suggested and the problem persists, the next step will be to trouble shoot the amplifiers and headunit. This will determine if the problem is being caused from the power side or the sound side. Let me know how it goes and we can go from there.
Working on this amp again...
Hey guys, I know I posted about this last year sometime, but I've finally gotten so annoyed that I've taken this amp out of the car and have it in pieces on my desk... I've also noticed there have been a few hits on this post so I'm sure some other people have had similar problems...
I've tested the amp with different input, cables, speakers, and wires and it still has the same problems as it had in the car. I know the problem is related to the amp itself now, not anything in the car. Now that I've had plenty of time to be annoyed by the issues I can maybe explain them a little better...
The noise is completely random, sometimes it's quiet and in a rear channel, sometimes it's really loud and present over the music in a front channel, once this started the amp also started popping when I shut it off. This never happened before. The noise will sometmies be a faint maybe 20 Hz clicking, and sometimes a quite loud maybe 60 Hz buzzing...
Does anyone know where to look to solve a problem with these symptoms inside the amp? I am quite handy with a soldering iron and I am an electrical engineer, so I'm not afraid to dig in.... I just don't have any amplifier experience under my belt so I need to know where to look, and what components to start with. I really wish I could get my hands on some schematics...
Thanks again for any help you can provide.
Hey guys, I know I posted about this last year sometime, but I've finally gotten so annoyed that I've taken this amp out of the car and have it in pieces on my desk... I've also noticed there have been a few hits on this post so I'm sure some other people have had similar problems...
I've tested the amp with different input, cables, speakers, and wires and it still has the same problems as it had in the car. I know the problem is related to the amp itself now, not anything in the car. Now that I've had plenty of time to be annoyed by the issues I can maybe explain them a little better...
The noise is completely random, sometimes it's quiet and in a rear channel, sometimes it's really loud and present over the music in a front channel, once this started the amp also started popping when I shut it off. This never happened before. The noise will sometmies be a faint maybe 20 Hz clicking, and sometimes a quite loud maybe 60 Hz buzzing...
Does anyone know where to look to solve a problem with these symptoms inside the amp? I am quite handy with a soldering iron and I am an electrical engineer, so I'm not afraid to dig in.... I just don't have any amplifier experience under my belt so I need to know where to look, and what components to start with. I really wish I could get my hands on some schematics...
Thanks again for any help you can provide.
PPI has been sold to a group that generally provides schematics for their amps. Contact the tech support guys to see if they can help.
tech-support@precisionpower.com
tech-support@precisionpower.com
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