Outboard DACs

All good things come to an end, although in the world of digital hi-fi sometimes that end comes around pretty quickly. Obsolescence isn't as 'built-in' here as it is in the smartphone market, for example, but technological evolutions, be they around chipsets, connection standards or format types, mean 'MK2' iterations of DACs and streaming hardware are a common sight. PS Audio's DirectStream DAC MK2, however, is rather more than a mere second-generation product.

Colorado-based PS Audio is known for a number of things: its products are handmade in its own US facilities and, as of last year, it only sells direct to its US customers. Here in the UK, PS Audio's equipment is sold more conventionally, through distributor Signature Audio Systems, which premiered the company's Stellar Phono Amplifier at the Hi-Fi Show Live at Ascot in October last year. That product, along with the Power Plant 3 AC regenerator [HFN Jan '20], is part of the new entry-level range from the company.

Boulder's founder and chief engineer Jeff Nelson gained his first audio engineering experience with studio mixing desks and the design of a professional cartridge tape unit. This led to a constructive interchange with the late Deane Jensen, the audio transformer wizard and the originator of a classic 'operational amplifier'. This was not an integrated circuit but one implemented at good power and wide bandwidth via the use of discrete devices.

When is a DAC not a DAC? When it turns into a multifunctional network-connected music player, that's when! Increasingly, the lines between products that exist to convert digital inputs into analogue audio and full-blown network players are becoming blurred. So, just as there are players provided only with digital outputs – network transports or bridges to be paired with an outboard DAC – so we now have DACs with network capability built-in. Add an app running suitable UPnP control software, and you have a complete streaming solution.

Well, it makes a change from the usual choice of silver or black… Yes, you can have the German-made SPL Phonitor xe USB DAC/headphone amp, which starts from £1899 depending on specification, in either of those colours if you want, but it's also available in the bright red anodised finish you see here. Not that it needs colour to catch the eye for the unusual battery of features makes it either intriguing or something of a head-scratcher: what do all those knobs and switches do? And then there's the pair of illuminated, retro-looking VU meters – this is clearly not your common or garden DAC/headphone amp.

I think I can be pretty confident in saying there aren't too many new British hi-fi components out there whose development has been government-funded. Clearly they do things differently in Germany, where the Federal Ministry of Economics and Energy underwrote the design and development of the network-capable DAC/preamp forming half of the subject of this test, T+A's £23,400 SDV 3100 HV. The project has borne fruit in the behemoth of a digital converter you see here, all 26kg of it, described as a 'Super High Definition Audio DAC with bit-perfect data transmission and resolutions of DSD1024 and PCM768'.