Network Acoustics tempus network switch
It was only a matter of time before Network Acoustics got around to making a network switch. The streaming specialists have built class leading ethernet filters and all manner of digital audio cables so a data or network switch was the next logical step to building a complete back end for those looking extract maximum performance from a streaming system. Network Acoustics products are created to reduce the amount of noise that can get into a streamer or music server, they started out with the ENO ethernet filter and associated Streaming cable and have since developed the more advanced muon filters that reached their peak with the muon pro, a truly remarkable device that does far more to enhance sound quality than it has a right to.
The tempus switch is a bigger step which explains why it has taken so long to come to market. It’s the first Network Acoustics device that requires AC power, and this is something that Rich Trussell and Rob Osbourn have been experimenting with on streamers for some time. Therefore tempus had to have a serious power supply and not a wall wart of the sort often supplied with a few audiophile switches. The power supply for tempus looks like becoming a standalone product in its own right because NA have developed a hybrid circuit for it that they believe to be unique and capable of delivering cleaner power than existing alternatives. The streaming world is full of low voltage devices that can be usefully upgraded in this way.
But to get to the meat of the matter we have tempus, this is a substantial switch that offers more ports than most audiophile examples and sits in a machined aluminium case that would not look out of place on a DAC or streamer at the same price. Expense has clearly not been spared on fit and finish and the fact that there are eight RJ45 ports and four SFP optical ports means that anyone wanting to combine audio and video streaming will have enough for their requirements as well as being able to add network attached storage (NAS) or a music server.
Under the lid you will find a processor that is more powerful than it needs to be so that it can manage the job of signal routing without having to try too hard, it’s a bit like having more power or headroom in an amplifier than is likely to be required, it means that the switch will cope with whatever demands are thrown at it with ease. And as this is not the case with computer grade switches that’s an important point, network switches have an inherently filtering effect on network noise but many fail to provide a benefit because they are electrically noisy devices that are run at the limit of their processing power. They can also add high frequency noise unless details such as the power supply are given thorough consideration.
Here the power supply has been given more thought than many digital components, the 12V supply provided with tempus is housed in a high quality acrylic case with an attractive matte finish. It contains what Network Acoustics call a hybrid power supply that “delivers ultra clean power normally only associated with the best linear supplies combined with the essential dynamics only a switched-mode can provide”. Network switches do indeed need the speed that switched mode (SMP) designs can produce but they don’t need the noise associated with many examples of the breed. Linear supplies (LPS) are found in the Class AB amplifiers that many of us use but while they can be very clean they are not necessarily very fast. Network Acoustics appear to be combining these technologies in some way to give tempus a good chance of performing without compromise.
There are no flashing lights on the ports, in fact there is only one LED on both switch and power supply, these lights can produce noise of their own so less is definitely more. Network Acoustics recommend using the gigabit ports for audio signal routing, but they do not encourage using the optical connections just yet. This is because the conversion between an optical and electrical signal undermines the benefits of this approach, the only exception being very long runs of ethernet. These SFP ports are included for “use with future products”. The cable supplied to connect power supply to switch is 75cm long which is a little shorter than is ideal in my system but I imagine that longer alternatives could be supplied on request.
Sound quality
I have been using an English Electric 8Switch with one of Chord’s Ground Aray devices and an iFi Power X supply as my audio system switch for some time, it works well and sounds good but experience with more pricey switches from Melco, Innuos and others have shown that it can be bettered. The tempus did the same thing very clearly by introducing a visceral sense of presence to the sound from streamer, music server and DAC, the imaging in particular solidified and made the sound significantly more real in the room. The soundstage was no longer between the speakers but right in front of me in uncannily palpable form; real close your eyes and the band is in front of you stuff.
With more listening it became apparent that the dynamics were stronger, by reducing the noise floor tempus allows quieter sounds to be clarified and this means that there is a greater difference between them and the louder sounds in a mix. This undoubtedly contributed to the sense of scale that this switch brings to so much music and the way that it feels as if the musicians are closer to you. Bass is also weightier and more articulate, this is presumably a factor of the reduced noise floor as well, by allowing quieter parts of each note to be heard you get more of the subtle hints about the shape and nature of each note. I was also very impressed by the way that fine details are extracted from every track played, details that enhance your appreciation of how well they are played, arranged and produced. With acoustic performances there’s more room for the instruments to breathe, the nature of the acoustic around them is clearly defined, in fact my regular switch sounds compressed by comparison.
With extended listening what really starts to make itself clear is the quality of timing. This is an area where digital systems have always struggled to match their analogue counterparts, I’ve tended to put this down to the processing required but it would seem that reducing noise getting into the system enhances timing to a surprising degree. The tempus really lives up to its name in this regard, tempus being Latin for time as in tempus fugit (time flies). Time and again (excuse the pun) it was made clear that the streaming system was timing better than it has in the past, the way that the different musicians interact on a live recording makes more sense and the precision of pretty much everything went up the next level without the addition of grain or glare. Fly Me to the Moon (Sinatra at the Sands) is not really my cup of tea but the way that the big band swings when it’s streamed through this is something else, it goes from sounding like a great recording to becoming a fabulous piece of music when the timing is this tight, and the brass no longer sounds hard and compressed just bright and brilliant. The lyrics on Kendrick Lamarr’s How Much a Dollar Cost became razor sharp, which heightens their impact and makes it even more clear that he is in a different league to most of his peers. What I love about this switch is the way it enhances transparency whilst staying bang on time, it brings out all the warmth in recordings that is usually only possible with analogue.
As I have a Network Acoustics muon pro ethernet filter in the system (between streamer and switch) I tried removing and replacing this to see if tempus would render it less effective, the short answer is that it doesn’t, for best results the muon pro is still essential. In fact I would go so far as to say that if you have a standard switch with no filter then muon pro would be the first step toward digital audio nirvana. I also tried the Ground Aray and found that to benefit tempus, it seems that even the best can be improved, it was ever thus in this game.
What’s more important is that tempus increases the quality and thus appeal of streamed music, I found myself playing albums that had not previously seemed that good and changing my mind. This is or should be the ultimate aim for any piece of audio kit, to make music more accessible and interesting, to take us away from the distractions of life and carry us to a different psychological and emotional place, and strange as it may seem a network switch can contribute in a very positive way to achieving this.
My final contrast with the 8Switch was as straight as I could make it, the Aray was removed as was a Tom Evans mains filter, but I couldn’t find the original wall-wart supply so stayed with the iFi. This made the upgrade in imaging even bigger, which means that noise suppression was revealing mountains of the low level detail that combines to bring out the space in the recordings. There was also a much greater sense of ease, the sound became more relaxed which is another analogue trait. It’s interesting that tempus has this ability to make digital sound like analogue but does it by reducing noise, something that analogue systems are generally not that great at, but they have other advantages of course.
Conclusion
I have to say that expectations were high for the Network Acoustics tempus and I have still been impressed, it has exceeded what I have heard with other high end network switches and raised the standard streaming sound quality to new heights in my system. I’m really looking forward to trying it with more fancy streamers and DACs but the result with a Lumin U2 Mini and Borderpatrol DAC SE have been eye/ear opening to say the least. It makes abundantly clear that you will never hear the full potential of a streaming system without paying attention to the details of how signal is delivered. If you are serious about streaming the tempus should be on your ‘must hear’ bucket list.