I love audio marketing. Sometimes I think that the same folks that do the media for political campaigns also do the ads in audio magazines and that sort of thing. Looking at the diagram, there are some silly things (of course), but the actual implementation looks about as good as you need to get for a sound card.
- Nichicon MUSE caps...OK. Powercolor must have meant DE-coupling caps, because these are just the bulk filtering caps on the power input, and over at the LDO regulators. On that point, it is good that they used LDO's rather than switching regs because switchers make a LOT of EMI (and are generally more costly). Anyway, given the frequencies of the transients involved in a PC, these bulk caps are only a piece of the noise-reducing puzzle. Quality ceramic or tantalum SMD caps are crucial to taking out high frequency noise from the power supply, and I do not see much in that respect.
- Molex Power Connection...BS. Supply ripple is going to be present on all of the 12V rails. I find it doubtful that the voltage supply on the PSU's Molex plugs is really much cleaner than that of the PCIe supply. Besides, that's what all those bypass caps are for.
- Daughterboard extension...OK. Note that the daughterboard gets its signal from the Cmedia DSP chip's onboard DACs, not the nice Wolfson DAC. So, ONLY the main stereo outputs will have the "hi-fi" audio signal. There is also another QFP IC to the right of the Cmedia chip, which might be the multi-channel DAC for the daughterboard. Either way, Powercolor did not bother to point that out, so it is probably one of the same chipsets that you would find in an onboard audio subsystem.
- Cmedia CM8888...OK. This is the real meat and potatoes of the sound card, and it's a commodity IC. The multi-channel audio outputs for the daughterboard either come from this, or the smaller QFP chip to its right.
- DAC...GOOD. The Wolfson WM8741 is a legit hi-fi DAC. Not much more to say there.
- TI LM4562...GOOD. These opamps have been on the market for about a decade. They are regarded as being good parts by the DIYAudio community (although arguing over opamps can basically be a religious war over there!). Anyway, not much to say here either. They are good performers for a relatively low price point. You could spend a LOT more on opamps with better specs, but the law of diminishing returns would set in really fast.
- Gold plated outputs...OK. Gold won't corrode, that's about the only real reason to care.
- Swappable opamps...BS. The opamps in there are fine. A few people may be on the "argue to the death about the best opamp" list and actually go do it, but there is no need to.
- Polypropylene caps...GOOD. The opamps are most likely configured as low-pass filters for signal content 20kHz and below, and for filter applications, poly caps are one of the types that are correct for the application. C0G/NP0 ceramics are also fine, and a lot smaller, but from a marketing standpoint the poly ones are probably a better choice since there is a general notion that all ceramic caps are bad for audio (and it's true, except for C0G/NP0).
So, this thing looks like a reference implementation of the digital / multichannel side, and they added some above-average analog bits for quality stereo listening. Is it worth $159? Maybe. While the implementation is good, the fact is that this thing is still inside the PC chassis where you will have a fair amount of EMI blasting around from high-speed high-current transients due to the CPU, GPU, RAM, etc. It might be better than an external USB DAC though, since those are limited to a noisy 5V supply (unless it requires a wall-wart with 12V output), and you would need a switching boost regulator to get high enough voltages to drive headphones adequately. Overall, I think that this would be better than a USP-powered external DAC, but not as good as an external USB DAC with its own 12V-20V power input.
Also, anyone that is going to bother with a nice sound card should take a look at the their audio source material. Lossy compressed files like MP3s and whatever most games used these days are going to introduce plenty of distortion from the compression algorithm. To really take advantage of nice analog hardware, you need to go with FLAC audio ripped directly from a CD.