Noise Coming Out Of The Amp When Connecting Pod Hd Desktop To Computer

[eytan3000]

hey:) 

Each time i connect my pod hd desktop to my computer with the firewire cable, I get a hiss noise frome the amp connected to the pod.

what can I do to fix it?

 

thanks

[toneman2121]

check input settings. i get hiss when input 2 is set to mic

[spaceatl]

+1....Try turning the mic trim all the way down...gets rid of the extra hiss...if you are not using a mic...

[SLBMusic]

I have had a similar issue. Not so much a hiss as a hum. This only when I had my HD500 plugged into the computer via USB. I also found that computer sounds were coming through the POD and out the amp. The only thing I can figure is that somehow the computer (Dell running Windows 7) is seeing the POD as an audio interface and sending audio out that way instead of the normal way (Steinberg CI2).

 

That may be entirely different from your issue, and I haven't bothered trying to fix it either. But just in case it IS part of your issue - there you have it.

[singlecut69]

I have the same problem with my desktop. Mic trim doesn't fix it for me. I have noticed that I don't have the hum problem when connected to the laptop running on battery power. Seems like it would be a grounding issue. The desktop is plugged into one power strip into an outlet, the HD500 and amp are plugged into another power strip at a different outlet. I guess i'll look into the comment about the computer seeing the HD500 as an audio interface, which i'm pretty sure it is since that is how I had to set it up to record and playback from the computer, only I didn't have the amp in the loop when doing that. I hooked the computer speakers right to the HD500. The hum is like when you have your amp running and don't have a guitar plugged in, touch the tip of the cable and that's the hum I hear.

[wildbillmojo]

Obviously without hearing your noise I can't be sure, but I had a problem with digital clock noise from the HD. The clock drives the internal digital electronics (CPU, DSP etc) and you'll hear this as a high pitch 'hum'. It's breakout onto you audio path is caused by a ground loop, and the only way to really fix it is to ensure the POD is using a completely isolated mains supply. You can buy isolators, they don't cost that much.

[GTLazer]

Not sure how much value you'll get from an isolator, as the POD has a low enough internal voltage that it has/needs no earth reference and relies on being grounded through connected equipment.

 

If you're getting hum caused by ground loop, the loop is from your PC, though the POD, to your monitors/other equipment.

 

I had a similar problem to many others where my laptop was causing noise. I bought a couple of XLRs so I could take advantage of the ground lift and found that it made the noise worse (go figure), so it could just be crappy-component noise, like my laptop, that is allowed to propagate by the loop. The solution there was to run on battery while recording, but obviously you can't do that with a desktop (and it's far from ideal with a laptop).

 

In theory, you could isolate the ground on one of the mains components to cut the loop, but there's a chance that this can lead to death by electrocution if there's a short in the isolated component when it's not connected to the grounded component. For example, a short to the case of your PC is fine while the PC is grounded through the POD to your monitors, but if you unplug the USB/firewire then put your hand on the case, then there's a chance you'll go bang.