Help!

[Silica 10+ year member]

I cant figure this out...

Have my two amps hooked up, 4 channel and mono block.. 4 channels works perfect, like a **** charm, now its supposed to. My mono block for some reason, when its in the car, no matter what i do, it will hum, and ihavn't even turned the car on... so i thought hmm bad rcas? I took a portable walkman, hooked it up to the amp, and hooked up a direct external speaker just to make sure it wasn't the sub or the rca.. hell na still hums.. at a pitch of like 1000 hz.. Sound like the rcas are picking up my cooling fan in the amp?? I pull the amp out of the car, and put it on the bench, throw 12 v at it, and fire it up. Hook up the walkman and speaker.... yeah no humming.. turned the amp upside down and sideways to make sure the fan is still good in it and no shorting out or something... nope couldn't get it to hum.. its been on the bench for 10 minutes now to see if it would start humming and nope... I dont understand.. //content.invisioncic.com/y282845/emoticons/verymad.gif.3f39c5c2fd57527b671fad3efdfac756.gif Put it back in the car... same **** problem.. //content.invisioncic.com/y282845/emoticons/verymad.gif.3f39c5c2fd57527b671fad3efdfac756.gif//content.invisioncic.com/y282845/emoticons/censored.gif.f9ad8e7c6db58c5530c5a0a20a3b5baf.gif

Bad ground? Ground loop?

Tim

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[forbidden 10+ year member]

Put the amp back in the car and do not mount it, instead place it on a piece of cardboard. Do not use the remote on wire or your cd player. Jump the contant power line to the remote on and use your discman, does it still hum? If so, where did you ground the amp to and what vehicle is it in?

 

[Bavarian3 10+ year member]

did u run ur RCA wire the same side as the power wire? if so that could be ur problem for sure. Ur RCA's should be run through the middle of the car to avoid any contact with power wires.

 

[forbidden 10+ year member]

Is the amp mounted anywhere near a vehicle electronic component like a car computer?

 

[Silica 10+ year member]

Well i kinda solved the problem... bad ground.. grinded down the metal, and bolted the ****er with straight nut and bolt, plastered the thing in flux torched it and tinned the ****.

bling bling, cut the hum by like 80%, now, the speaker i was using to test was a 4" bulk speaker that i had laying around, the hum was still there, but like must had been 1000-3000hz, soon as i hooked the sub up, nothing. no hum at all.

As well i put a ground loop isolator inline with the RCA's, problem solved!

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