Brand new AMP, Busted..

**Biograph1001** · 02-12-2006, 08:33 AM

Hi! This week i bought an Infinity 5760A Amp, 6chan amp.... i installed it, replaced my old amp... it sounded nice at first when the car was not running, this aint a groundloop problem so continue reading please :P... any who, when the car is running i get this awfull hiss only from the front right channel, when the car isnt revving at first the hiss aint noticable, but when i rev the engine a bit the hiss builds up and then stops building up to become static... so i dont know, i have tried 3 groundpoints and tried switching around my speakerwires and all... oh, and i did this test without any input to the amp, had nothing connected to the low level inputs.. My first impression is that the amp is somehow broken, some transistor or something at the front right channel is busted? Keep in mind that the amp was like 3 days old..

Please help!

**Greeney** · 02-14-2006, 04:40 AM

open ur amp case and look for any noticible damage. sounds like you dont have a good enough ground to me, scrape away as much paint till u reach bare metal

**maded** · 02-14-2006, 05:03 AM

just hijacking your post, BioGraph...

i don't really like the idea of scrapping paint off the body for a ground... getting ground from the batt works just as well, wouldn't it?

**Will Albers** · 02-14-2006, 08:43 AM

sure, just make sure you ground cable is the same gauge as your 12v cable.

pretty pricey where it would be easier just to scrape away the paint, put in a self tapper and then spray some rustoleum over the bare metal. To each their own

**tech55** · 02-19-2006, 05:37 AM

you need the best ground you can get with the shortest length of wire. The shorter the wire the less resistance and less chance for any ignition noise to enter the amp or anything else hooked to it. I would say hook it to the body. Running a long wire to the battery is like an antenna for EMI into the grounding of all your equipment

**gameboy** · 02-19-2006, 10:20 AM

pull the speaker out and make sure the wires attached to the speaker are good and tight, also you may want to upgrade the ga of the speaker wire u are using.

also, check to make sure your are running your speaker in the correct polarity.

one last comment - make sure your speaker wire is not grounding anywhere

**DavC** · 02-19-2006, 11:49 AM

swap over the front left and front right speaker cable on your amp.

Does the problem stay in the same place or move to the front left?

**Jahntassa** · 02-19-2006, 11:54 AM

Yeah, try what DavC says. I had to swap my front left channel with my rear left channel going from my wife's Pioneer headunit to the Sony 4 channel amp she has, same kinda issue, and it just 'went away'. So try rearranging the RCA connections and see if you can make it go away, then reconnect the speakers to the amp so the RCAs and speakers match up.