Well, the problem is definitely caused by the front panel then, and the simplest solution is not using the front panel. It is often badly implemented in PCs, and is prone to interference due to ground loops and/or EMI. It can be fixed or improved by DIY modifications, but this is only recommended if you are familiar with making such changes. A different case could also fix the problem, but it is a rather inconvenient solution, and the new case might be just as bad anyway.
So, without using the front panel, some possible solutions include:
- connecting either the headphones or the speakers to the front channel jack at the rear; this is cumbersome due to the constant unplugging
- doing the same with a simple external switchbox to avoid having to unplug the other device
- a splitter and a cheap (e.g. FiiO) headphone amplifier on the rear jack
- using a cheap external DAC for the speakers, like the FiiO D3 that can be connected to the S/PDIF output of the sound card
- connecting the speakers to the rear (surround) channels, and using stereo upmixing to 4 channels; unfortunately, this solution would probably only work with some software, and not others (depending on what Windows audio API they use)
Edited by stv014 - 10/2/12 at 4:12am