So how does this darn thing sound? I do not have a lot of higher end testing equipment, so I have to rely on the Human Ear Mark 1. I tested with multiple 2.1 speaker systems as well as several different headphones. Unfortunately, the highest impedance set I have are the Grado SR125s which are rated at 32 Ohms. As mentioned before, some higher end units can have up to 600 Ohms of impedance. Having such a high impedance make these types of headphones a hard sell for the mobile market (requires more power to drive these units). These are the types of units that Gigabyte designed this board for.
I utilized a nice, older Logitech 2.1 system which pushes some 120 watts between the subwoofer and the satellites. I have to admit that this is about the cleanest integrated sound setup that I have ever heard push these particular speakers. I would dare say that it is quite an improvement over some of the sound cards I have tested in the $25 to $50 range. It does match overall output quality of higher end sound cards that are $50+. It is almost as clean as the very high end sound cards that fit in the $150 to $200 range. Where it differs dramatically from those parts are the added software based features that these cards typically integrate. DSP functionality to improve lossy content, more 3D effects, ASIO, and other features of these higher end cards are obviously not available with this board.
Lower impedance headphones are pushed very well at the standard 2.5x gain. The output is clean and the volume can go up really high. Bass response is good with a nice punch, and I did not experience any real boominess. Complex compositions did not suffer (such as orchestral music with a lot of positioning and representing audio content from the very low end of the frequency scale to the very high end). Poorer quality source material will be accentuated by this setup, even with the lower end and lower impedance headphones. Good quality source material will shine though.
I then tested with the 8x gain with the higher impedance Grados. These get loud really fast. The user will have to really work on volume settings and levels to get the most out of their headphones. 600 Ohm units will receive the greatest overall benefit as the board acts as a good quality amplifier. Lower impedance headphones should probably stick to the standard 2.5x setting. This setting does improve bass response and overall performance. The output is very clean, and the SNR of the implementation is very high considering it is onboard audio. Have I mentioned that it does get very loud?
Overall, the audio implementation is really top notch when it comes to onboard sound. Gigabyte did a very nice job with the design. The sound quality is excellent for integrated audio, and overall approaches that of cards in the $150 to $200 range. The ability to swap out the L/R OPAMP allows individual users to customize the color of their sound. It honestly is the best onboard sound setup that I have yet experienced.
It is not perfect. I did notice a couple of clicks and pops when other components were activated, such as the optical drive being opened and closed. Gigabyte did a pretty good job in isolating the circuitry, but the inside of a computer case is a pretty electrically noisy beast. During gaming or just music listening these issues do not crop up, unless of course the user decides to do such operations as opening the drive to swap out some sort of media.