Most desktop pc's built in sound chips within the last 10 years or so have had capable DACs and noise shielding, at least with the mid grade and up motherboards. In the case of the new HP I have, they even make mention of the noise shielding in the specs somewhere. I have been able to plug the headphone jack to RCA on older, and newer amps without so much as a hiss.
Audio quality has been competitive with pc's for quite some time now. Unless it is some bare bones, bulk buy, office box, or some bargain from an import ridden, box store, the sound chip contained on the board should be adequate.
Simply look up the sound chip on your computer's specs and research it.
Features
Hardware Features
- DACs with 95dB SNR (A-weighting), ADCs with 90dB SNR (A-weighting)
- Ten DAC channels support 16/20/24-bit PCM format for 7.1 channel sound playback, plus 2 channels of concurrent independent stereo sound output (multiple streaming) through the front panel output
- Two stereo ADCs support 16/20/24-bit PCM format, multiple stereo recording
- All DACs supports 44.1k/48k/96k/192kHz sample rate
- All ADCs supports 44.1k/48k/96k/192kHz sample rate
- Primary 16/20/24-bit SPDIF-OUT supports 32k/44.1k/48k/88.2k/96k/192kHz sample rate
- Secondary 16/20/24-bit SPDIF-OUT supports 32k/44.1k/48k/88.2k/96k/192kHz sample rate