5.1 headphones with amp, getting interference

[TomD22]

Hi all

I just bought a pair of Medusa 5.1 surround headphones, which come with their own independantly powered amp box. I have an audigy 4 sound card (please, no advice on either, they're already bought).

When i plug the headphones directly, via their single wire, into the soundcard, all is well (although of course i can only have stereo, not 5.1 sound).

To get 5.1, i have to use the amp. It has three cables which go between the soundcard and it, and then the headphones plug into the front of it. My problem is that some part of the setup is picking up interference.

All the time, there is a faint backround hiss. The really noticeable thing, is when i am using my wireless LAN. I have a transciever on a wire from a USB port. When the LAN is active, it has an LED on the front which blinks as information is sent, and this blinking is matched exactly by loud crackles and pops through the headphones. I know for sure that it is the actual transmissions from the WLAN being picked up, because when i shield the transciever with my hand, they pops reduce in volume.

I only get this problem, when i am using them amp. If the headphones are plugged directly into the computer, or another set is used, no problem.

I have tried shielding the wires from the soundcard to amp with ferrite rings, but it hasn't helped. This has made me think it might be the amp itself that is picking it up.

Does anyone know which bit of the setup is most likely to be picking up pops and crackles from my WLAN? And more pertinently, does anyone know of a solution? (i have of course moved the transciever as far away as i can, but seeing as the signal is designed to reach across a whole house it doesn't help)

Thanks

Tom

[spago]

Move the amp around. Also set the volume on all channels to 5~6.

[Beckman]

Hi all

I just bought a pair of Medusa 5.1 surround headphones, which come with their own independantly powered amp box. I have an audigy 4 sound card (please, no advice on either, they're already bought).

When i plug the headphones directly, via their single wire, into the soundcard, all is well (although of course i can only have stereo, not 5.1 sound).

To get 5.1, i have to use the amp. It has three cables which go between the soundcard and it, and then the headphones plug into the front of it. My problem is that some part of the setup is picking up interference.

All the time, there is a faint backround hiss. The really noticeable thing, is when i am using my wireless LAN. I have a transciever on a wire from a USB port. When the LAN is active, it has an LED on the front which blinks as information is sent, and this blinking is matched exactly by loud crackles and pops through the headphones. I know for sure that it is the actual transmissions from the WLAN being picked up, because when i shield the transciever with my hand, they pops reduce in volume.

I only get this problem, when i am using them amp. If the headphones are plugged directly into the computer, or another set is used, no problem.

I have tried shielding the wires from the soundcard to amp with ferrite rings, but it hasn't helped. This has made me think it might be the amp itself that is picking it up.

Does anyone know which bit of the setup is most likely to be picking up pops and crackles from my WLAN? And more pertinently, does anyone know of a solution? (i have of course moved the transciever as far away as i can, but seeing as the signal is designed to reach across a whole house it doesn't help)

Thanks

Tom

Could be a ground loop. Try pluging the amp and the PC into the same outlet via a surge protector(power strip). Also, does your wireless LAN have a seperate power connetion? If so you will want to make sure that shares the same ground as the computer and amp.