You might think that you can't get much in a metal box the thickness of three CD jewel cases and rather smaller in footprint, but Pro-Ject has managed to get a power amp in one, a two-input line preamp in another, headphone and phono amps in a further couple: and in this one, a dedicated USB-only DAC.

Not that space was the problem here. Thanks not least to a handy little integrated circuit from Burr-Brown – one of the big names in digital audio chips – Pro-Ject has managed to fit the entire circuit on a board with a surface area of some 26 square centimetres.

Were it not for the height of a couple of output coupling capacitors and the output sockets, the board would comfortably fit in a Swan Vestas matchbox!

Power via USB

Rather more sensibly, though, Pro-Ject has put it in a robust metal case, with a choice of black or silver front panels available. on the rear are a pair of phono outputs and one of the smaller variants (why there's more than one type is an enduring mystery) of USB input.

There's no power connection at all, as power is taken from the USB line. That saves hassle and expense, but does impose one restriction: the power coming down a USB cable is delivered at only 5V, so unless trouble is taken to step this up the maximum audio output will be limited to only a volt or so – in fact Pro-Ject quotes 0.775V – and you'll need to advance your amp's volume control a bit. But practically all modern amps have enough gain range for that.

Software installation

The beauty of USB is that you just plug in and go. it sets itself up and that's it – in principle. Actually it may not be quite that simple. Depending on your computer and the software installed on it, you may or may not have 'kernel streaming' drivers which ensure a bit-accurate output via USB. Pro-Ject had omitted these with our unit, but assures us they will normally be supplied: luckily we already had them installed.

There can also be occasional problems getting output via new audio hardware, usually because of the multiplicity of software settings which won't all necessarily be changed automatically by the new hardware as it installs itself.

Still, we had no trouble getting our sample working and were rewarded with some very lively sounds. 'Lively' is very much the key with this DAC. It isn't always the most subtle device around but it does get on down and boogie without any reservations at all.

The sound has a real 'snap' to it and while bass extension may not be the ultimate, it's certainly more than good enough to deliver plenty of impact when a drummer whacks something hard.

Limited precision

That's the plus side. The minus side is that detail stop some way short of fabulous, though it's arguably as good as one might dare to hope for at £75.

You can hear most of the way into a mix, but the highest precision of timbre, and of both tonal and spatial definition, escapes the USB Box. Tonal balance, however, is good, with just a hint of brightness but a very neutral midrange.

For the price of a mid-range pair of interconnects, the USB Box delivers a performance which we are happy to call excellent value. It gets on with most music, but its lively and engaging ways best suit it
to rock, upbeat jazz and other energetic styles.

As a budget upgrade to a computer sound system, or indeed partnered with a cheap laptop as a budget sound server system, the Pro-Ject USB Box is hard to beat.