Zx450 popping

[98peterbilt]

New to the forum long time looker. Problem with my Zx450 amp. When changing songs at the end or the beginning of another song it has a pop that comes through the speakers it does it all volumes I have checked the grounds and power supply. Bear with my ZX 400 and also the problem isn't there with my Alpine amp so that's lead me to believe that it's something inside the amplifier if anybody can send me in a direction or has had similar problems please let me know thank you

[ttocs]

it only comes out of the speakers that the pg play? I have heard noises that sound like pops between songs that sometimes I attributed to the decks pick up someone getting noise introduce to it from the motors in the deck. The amp should not have a way to introduce noise just between songs. If you just turn it down all the way does it still do it?

[98peterbilt]

Yes it's only the subs. Yes it still does it regardless of how loud it is. I figure it's the amp cause my zx400 nor my alpine do it. I have read different posting on the web about how the caps would start to go out an might do this but am not clear on how to diagnose them.

[trickyricky]

See if you can post a picture of the xover board showing the components...be extra careful not to put too much stress on the ribbon cable as they tend to break at the solder connections/joints. Just trying to see if there's two resistors burnt/damaged/open.

[98peterbilt]

Ok. When I get stopped either tonight or tomorrow Thanks for the reply

[98peterbilt]

It's not letting me upload the pics.

[Eric D]

If you hear a pop when changing songs, I am guessing this would be a problem with your head unit, not your amplifier. Even though it does not happen with your Alpine amplifier, the problem is still likely related to the head unit. My guess is the head unit has a muting circuit, which does something with ground, and the ZX450 has a different preamp section than the ZX400, so that is why it behaves differently.

[98peterbilt]

I would say maybe but it happens at random during songs also. So I'm still leaning towards something wrong with the amp.

[Eric D]

If it happens at random, but the other amps don't do it, then yes I would believe there is something wrong with the ZX450.

[98peterbilt]

Sorry. This has been one of those irritating things an I forgot to say that it was happening at random also.

[98peterbilt]

Well I have been doing some more tinkering. My test bench is a 25amp power source that I use to run my old rubicon 502 that runs my home stereo sub. So that is how I fixed my 752 Phoenix ryval an other amps. So I put the 450 on the setup an I get a hum through the sub. Talk about frustrating. This amp is like my unicorn. The only one I want to run an was my favorite when I put it away. I have checked the xover board for burnt or broken resistors. Anyone. I will try again to post pics.

[trickyricky]

Look at the resistors that are tied to the signal ground (rca jacket tied to actual signal ground or secondary ground) I believe they are 100ohm but they get very toasty and most of the time are open (bad).

[vwdude]

You said something about diagnosing for bad caps, let me say this, no diagnostics necessary, the power supply caps need to be replaced. I've had similar issues with other amps and it has been signal caps that have gone bad. Look at all of the small caps for one that's bulging and/of has crust around it. It's possible that your power supply caps are also causing it. Before further diagnosing get it recapped. Either do it yourself if you are capable or have it done. That might resolve the issue.

[98peterbilt]

Thank you. I was leaning towards them cause of all I have read about the caps causing fires. Just have to find some caps. Would you have a good place for replacements. Thanks for the nudge

[Eric D]

http://www.soundbuggy.com/Eric/Car%20Au ... index.html

There is a link in there for the caps you need.