Need help: Preamp out grounds went bad.

A.J.C · 02-12-2007, 10:42 PM

I have a Pioneer HU. I recently got a ground loop problem. The speakers had a wine that went with the rpms of the engine. I narrowed it down to the preamp outputs. If I touch a ground wire to the preamp rca ring, the noise completely goes away. I have heard pioneers are notorious for this problem.

My question is: What is the best way to fix this? Should i take the radio apart to fix it or solder a small wire to each ring and connect it to a ground?

Here is a picture of the back of my HU:

pentavolvo · 02-12-2007, 10:43 PM

solder a small wire to each ground and connect to ground is the easiest way to do it and it works

A.J.C · 02-12-2007, 10:45 PM

Quote:

Originally Posted by pentavolvo

solder a small wire to each ground and connect to ground is the easiest way to do it and it works

Thanks for the quick response. Thats what I'll do.

Fasthotrod · 02-13-2007, 10:58 AM

I hate to ask such an obvious question... but I assume your HU is properly grounded? By that, I mean the HU chassis... not just the black wire in the HU wiring harness.

Can you use an ohm meter and 'ring out' the chassis ground and RCA ground on the HU? I'd check multiple points... one being the small screw between the RCA jacks. It might be as simple as making a small jumper between that screw and the HU chassis ground... followed to a hard ground to your car.

Just my two cents.

Mark

pentavolvo · 02-13-2007, 04:18 PM

preouts are known for blowing grounds on pioneers radios