?'s for the stereo guru's

[07heri]

Alright all you stereo guys.  Hoping you can help us sort out a noise issue.

PBR300x2
62.11's
No head unit, just an Ipod

When all connected this thing actually sounds pretty damn good for an experiment/project.  The problem is noise.  Not hissing or engine noise, but a scary loud buzzing when the Ipod is disconnected.  If everything is connected and the amp powered up you wouldn't think there was issue.  It's when the Ipod cable or the RCA's are disconnected, that's when the loud buzz happens.  Not just when they are sliding out of the connections, but when they are totally disconnected.  It stays buzzing with the Ipod disconnected and the cable just sitting there.  Also when I touch the cable, connected to the amp but not the Ipod, the buzzing gets louder. 

As I said, if it's all connected first, then the amp is powered up, no noise.  But god forbid I try to pull the cable out of the Ipod while the amp is powered up....the buzz is loud.

I'm not a stereo or electronics guy at all, so any input or feedback would be greatly appreciated.

[speedzter]

Sounds like a shielding problem.
Either the shield wire is not connected at the amp end or even reversed with the signal ?

[07heri]

Sounds like a shielding problem.
Either the shield wire is not connected at the amp end or even reversed with the signal ?

Can you elaborate on this?  Brand new cable.  Tried another and same result.  Im open to learning about this so if you can explain what you mean that would be great.

[speedzter]

I just realized you are running the amps "stand alone" .
When you unplug the input to the amp the input wiring acts as a sort of  "antenna: , and picks up all sorts
of noise when you loose your ground reference from the input device.
What you need to do is to terminate the input to the amp.
You can try a few things, one of which is to wire up a volume control potentiometer  between the amp and the input, the other thing you can do is to add a terminating resistor across the input .
I think a volume control would be a wise choice.

http://sound.whsites.net/pots-f6.gif

[speedzter]

Found a simple "how to" for you :

http://emotivalounge.proboards.com/thread/23408

[Hossamania]

How about an on/off power switch for the amp?

[07heri]

I just realized you are running the amps "stand alone" .
When you unplug the input to the amp the input wiring acts as a sort of  "antenna: , and picks up all sorts
of noise when you loose your ground reference from the input device.
What you need to do is to terminate the input to the amp.
You can try a few things, one of which is to wire up a volume control potentiometer  between the amp and the input, the other thing you can do is to add a terminating resistor across the input .
I think a volume control would be a wise choice.

http://sound.whsites.net/pots-f6.gif

I think you're on to something.  Breaking the ground when unplugging the ipod makes sense.  A head unit probably is grounded and that ground is nonexistent when I yank the 3.5 cable out of the Ipod.

[07heri]

How about an on/off power switch for the amp?

Ran a toggle switch on the remote turn on.