Diamond USB Xtreme Sound XS71HDU Review

Late last year, we reviewed the DIAMOND Xtreme Sound 7.1 XS71HD, and found it to be a suitable replacement for onboard audio for a good price using a PCI-E slot. However there are certain cases where an internal upgrade isn’t feasible. Perhaps you don’t have the room for it due to existing hardware, or you simply couldn’t be bothered to get in there and install a PCI-E card. A USB audio upgrade may be worth considering -it can even provide its own advantages over an internal upgrade as we’ll see.

The product we’re looking at today is Diamond USB Xtreme Sound 7.1 XS71HDU, and while it has a very similar SKU to the former model, it has a quite a few different aspects which make it unique.

There are plenty of USB audio options out there, ranging from $4 to $400. Obviously you usually get what you pay for, and the products that pack the same impressive spec sheet as the XS71HDU are few and far between (and these are the ones that sit in the $400 range). The XS71HDU features 7.1 channel analog output, as well as digital input and output, and line-in and microphone ports. The impressive thing – especially at this price range – is that each input and output is fully capable of 24-bit 192 kHz audio. Until now, the only other options you had to achieve this kind of connectivity was to install an internal soundcard, or buy a very expensive one.

Let’s see if the $70 Diamond USB Xtreme Sound 7.1 XS71HDU performs up to these lofty expectations.

Diamond USB Xtreme Sound XS71HDU Review

The XS71HDU consists of a nice looking control pod with its inputs and outputs placed on each side – at least it looks nice and clean when there aren’t a bunch of cables sticking out from every side. The volume knob can also be pressed to work as a mute button.

On the analog output side, you’ll find the 7.1 channel outputs – the center channel is shared with the subwoofer. All analog outputs and inputs use 3.5mm jacks, except for the front channels. In this case, gold plated RCA adapters are used instead. An adapter is included if your speaker setup uses standard 3.5mm connectors (as most PC speakers do).

The XS71HDU has a separate headphone output placed with the two analog inputs. The headphone output has its own line driver which we’ll test separately.

Finally, we have digital audio output and input, in the form of TOSLINK optical connections, along with the USB port which works for both data and power. The XS71HDU draws very little power – 0.25A (1.25W at 5 volts) by our measurements using a Brando Charger Doctor (review coming soon). This is actually less power than most backlit keyboards at higher brightness levels, so it’s quite efficient, and suitable for laptops.

Included in the box are nothing more than what you need for a very basic analog stereo setup; a USB cable and an RCA > 3.5mm adapter.

Let’s take the cover off and see what makes the XS71HDU tick:

Before looking at each component, I’ll mention now that the XS71HDU has a relay switch that gives it a ‘click’ when it is being powered on and off. This is to prevent speaker popping during powerup.

After disassembling the XS71HDU, we get to take a peek at the important components that make it what it is.

The most important piece of the puzzle is the C-Media CM6620 audio processor. This model is designed specifically for USB products like this, and is what gives the XS71HDU its 7.1 channel capabilities, along with line in and mic in, all at 192 KHz 24 bit.

The CM6620 includes an integrated microprocessor (a very basic 8051, but it does the job) that works with external flash (the Cfeon en39lv010 you see in the first disassembled picture)  allowing it to support all the media enhancements that we’ll discover on the next page.

It needs a codec to convert between analog and digital, so it is paired up with this:

This is the CM9882A codec, which we’ve seen on everything from the Diamond XS71HD to the Asus Xonar Phoebus. It can provide an SNR up to 106 dB (Diamond claims 100 dB for the XS71HDU) and ~95 DB THD+N. It is also capable of 192 KHz @ 24 bit – in fact every single input and output on the XS71HDU is fully capable of that resolution.

This is the line driver used for the headphone port. It’s an Anpec APA2308, specifically designed for portable audio solutions like this. It can deliver a 280 mW of power to an 8 ohm load, or up to 110 mW to a 32 ohm load. We’ll be testing this separately from the main stereo output, of course. Only one output can be used at a time on the XS71HDU.

Here’s a quick look at the specifications before we move on to software and performance testing: