New amp has whining noise

[Bob 50]

Took out HU and ran only Pos and Neg off amp with HU not contacting vehicle and whine still there so it seems that the last option is the capacitor or just run a seperate battery in the trunk (dont like that idea though).

Amp is only about 100w rms per ch (4 Ch)

Thanks again everyone and if I could have possibly missed anything shoot a reply.

Bob

 

[xguntherc 10+ year member]

See reading something like that makes me wonder, u said its still there after completely removing the HU, but with my setup the whine stops when I power down my HU, while driving and increasing rpm the whine gets louder, then when I powered down the HU witch then powers down the amp the whine stops.. on mine at least. I just bought a DMM and ill be checking my grounds better tonight

 

[Bob 50]

Grounded the RCA outs from the HU to the HU case and that reduced the whine by 90 percent and with the gain at about 40 percent the whine is completely gone.

Thanks for the help,

Bob

wow I am going to start charging my Son by the hour for audio work!!!

 

[Bob 50]

My Son came up with a capacitor (1 farad Sosche) and wired it up which was very simple. The question I had is that it comes on as I would think when you turn on the car but then shuts off in about 60 seconds and then when you turn the key off it comes on for another 60 seconds and so on. This is a used capacitor and probably better to just buy a new one, but any thoughts.

Thanks

Bob

 

[Stetsom Rep USA 10+ year member]

caps operate when there is a change in voltage , when you shut off the car it will stay on till the voltage stabelizes, or comes to the rest voltage. I run a 5 farad cap in my work van and it comes on when it needs to. I dont think there is a problem with your cap.

 

[clayelliott]

do this to the HU, then plug in the rcas.

OK. First I'd like to thank edzy for this picture and the advice. Thanks a lot for sharing. You've made my night.

Then I'd like to give Pioneer a big ole fat FU for putting such a POS HU on the market!

I've been troubleshooting this for days and have tried just about everything to fix the engine whine in my system. After spending over 12 hours reading and running new cable I read this, try it and in 5 minutes realize the noise was 100% related to Pioneer's terrible RCA grounds. I can't believe this is common knowledge and they haven't done anything about it.

For anyone with a Pioneer head unit using the RCA outs BE-WARE and read edzy's post! FYI - my HU is a Pioneer DEH-P7000BT and the RCA ground problem made it unbearable to have my radio on unless it was really cranked...but once I grounded them as pictured (well, only the left side of each cable was necessary) ALL OF THE NOISE WENT AWAY!

I will never buy another Pioneer HU again...

Thanks again edzy!!!

 

[edzy 10+ year member]

Np, Glad it worked out for you.