Overview
Inside the box, and a very nice packaging job by PowerColor. You get the Devil HDX main board, the 7.1 channel daughter card, dead-tree installation guide, driver CD, two (short) ribbon cables, and a ⅛” to ¼” adapter to plug in your clearly inferior ⅛” plebeian headphones.
The main host bus card contains the headphone output, as well as RCA output for amplified speakers, along with coax and optical digital outputs for external decoders. Really quite a lot of meat on this Devil. And yes, you can swap out opamps, if that’s your thing. Main codec chores are handled by a Cmedia CM8888, taking on the 7.1 DAC and ADC (microphone) duties.
The headphone output is unusual, too. I have several pairs of headphones and headsets, but my main daily driver is a pair of battle worn AKG K701s. These are 32 Ohm, full sized, open back headphones, with a ¼” plug. That ¼” plug, or 6.4mm, becomes a big deal when you’re trying to plug into a computer. Almost all high-end headphones will have a ¼” plug, which always puts into doubt any source component that has a 1/8” (or 3.5mm) plug. So I dig around in various boxes trying to find an adapter. Using an adapter always makes me think that I’m losing fidelity. So, big win for the Devil HDX for sporting the ¼” plug. Also, I actually can’t find my ¼” to 1/8” adapter, either.
There’s always a lot of numbers printed with sound cards. Unsurprisingly, since the days of Creative’s Audigy line, the SNR is the largest number printed on the box. Signal to Noise Ratio (SNR) is a simple measure of how much electrical noise is being added to the signal by the device. In this case, the Devil HDX’s -120dB for the ¼” jack is pretty good, if not top of the line for a discrete audio card. On board audio is getting better, but of course still not in the same league as a dedicated, discrete audio card. A much better gauge of audio quality is THD+N, or Total Harmonic Distortion plus Noise. I won’t get into even and odd-order harmonic distortion, nor tubes versus integrated circuit amplifiers, and how it affects the sound you hear. But, suffice to say that the Devil HDX has got THD+N well under control at 0.00039% (108dB). That’s a lot of zeros, man.
Much to do with these numbers come from the chips on the Devil HDX and its design. It appears that both the headphone output and RCA outputs are driven by the dedicated opamp, which is capable of driving up to 600 Ohm impedance headphones. To deliver current to this kind of load, you need an external power supply, which, as the Devil HDX would have it, it has it!
