Network Acoustics Tempus

REVIEW
Jason Kennedy
Oct 16, 2024

Just as an F1 car is nothing without the team behind it, a streaming system cannot deliver high resolution without the proper equipment behind the scenes. It has become increasingly apparent that the sound quality limitations in a streaming system are not only found in the streamer or DAC but in the amount of noise that connections to the network bring in.

The name ‘Network Acoustics’ gives you a vital clue about this company’s angle. It started out making filters like the eno and muon that are designed to reduce the amount of noise getting to a streamer and has expanded gradually into almost all the other aspects of network audio save for streamers themselves. Network Acoustics is Rich Trussell and Rob Osbourn. Both are obsessive in their quest for the absolute streaming sound, and they seem to have a good ear for doing the job correctly. Their muon2 USB cable is the best that I have come across, as is the muon pro Ethernet filter; there is a lot of competition in both arenas but Rich and Rob remain at the front of the field.

Tempus time

Last year, Network Acoustics launched the Tempus network switch, the first fully-fledged piece of electronics to bear the brand. Anyone who has a wired streaming system should have a switch between the network and the audio system; even the cheapest computer-grade example will provide a degree of isolation from interference that runs around the Ethernet in any home. It is the least expensive upgrade available, but doing the job properly is not easy. Melco proved the point with its S100 a few years back and followed that with the S10, essentially the same switch with a separate power supply, a year or so later. Both products proved that if you pay attention to reducing noise in the switch, the streaming system will benefit to a significant degree.

Network Acoustics Tempus Black

I asked Rob Osbourn why sound quality is affected by Tempus to the extent that it is; he explained that it comes down to separating power from the signal; there is electrical noise in the AC power, which will pollute the signal itself if not adequately filtered. And that’s assuming you have a decent power supply in the first place. Computer-grade switches have basic switching supplies that add to the noise problem.

Network Acoustics’ experience building Ethernet filters must have come in handy when devising a means of reducing noise on the mains. Still, the company also decided to build a dedicated power supply for the purpose, because this element needs to complement the electronics in the switch if the results are as good as possible. Inconveniently, the high speed of operation required within a switch means that the go-to audiophile solution, a linear power supply, is not entirely appropriate. So Rich Trussell designed a hybrid power supply employing a combination of linear and switching techniques to produce 12V of the cleanest power at the desired frequency.

Excessive power

Network Acoustics also gave Tempus an excessive amount of processing power. Just as a high-power amplifier doesn’t have to try when it comes to controlling a loudspeaker, an over-specified processor will produce a cleaner signal because it does not have to work hard. Clocks, I am told, do not make a tremendous difference to network switches; a variety of types were tried, and Network Acoustics found that the standard variety gives the same results as the audiophile types found in streamers and DACs.

The company also found that offering multiple ports had no negative impact on results. Some brands take an eight-port switch and put it in a nice box with just one connection, but this is just pandering to the ‘less is more’ leanings of hi-fi junkies. Network Acoustics’ feeling is that by offering a good range of ports, Tempus can be used to benefit AV systems and TVs as well as the audio system, which, if the advantages seen when adding an Ethernet filter to a TV are anything to go by, could be significant.

Tempus has eight RJ45 ports, four SFP ports, and a sleek aluminium chassis. Network Acoustics has provided the SFPs for future products, presumably of the optical to electrical conversion variety, but doesn’t recommend this connection on sound quality grounds as things currently stand. There are no flashing lights as on conventional switches, just a single green LED to let you know that it’s powered up. LEDs produce noise, so the fewer, the better. The power supply inhabits a matte black acrylic case and is supplied with a usefully long 1.25m connecting cable.

The network

The support system behind my Lumin U2 mini streamer consists of a Cisco Catalyst 2960 S1 switch feeding the computer and Ubiquity wireless access point, which is connected to an English Electric 8Switch with a Chord Ground ARAY noise reduction device and an iFi Power X supply, this connects to the streamer and Melco N10 server with a Network Acoustics muon pro filter between switch and Lumin. So, it was reasonably well sorted before I substituted Tempus for the 8Switch, which it should be said is a considerably more affordable switch at £500, albeit the Ground ARAY adds another £550.

The Tempus effect was not subtle; it was like going from 2D to 3D; the sound was projected into the room with a visceral presence; it was no longer trapped between the speakers but opened up with palpable realism. Once the change in imaging had sunk in, I noticed that dynamics had increased without any volume change as well, Tempus brings the music closer and makes it more accurate and solid. The bass on John Martyn’s ‘Glory Box’ (The Church with One Bell) gained weight without any loss of articulation.

Timing, too, stepped up a notch and made the genius of Joni Mitchell’s ‘Don’t Interrupt the Sorrow’ (Hissing of Summer Lawns) even more apparent, while an excellent recording of chamber music gained room to breathe, making the previous rendition seem compressed, it was captivating. Further listening revealed that this was happening because the background grunge, essentially the noise floor, had dropped, which takes away hardness and replaces it with calm quietness, a much cleaner three-dimensional canvas for the sound to be painted on. There is more dynamic range because the noise is lower and this allows the quieter sounds to be more clearly resolved, the lyrics on ‘How Much a Dollar Cost’ (Kendrick Lamarr, To Pimp a Butterfly) are razor sharp, not sonically but in their acuity, and the extra transparency that Tempus brings to the presentation allows this to be more easily appreciated.

Outside in

With music streamed from Qobuz rather than the Melco server the results are very similar, the Tempus allowing an ease and clarity that the 8Switch and Ground ARAY can’t get close to. More surprising perhaps is that the timing improves with the Network Acoustics in charge of signal routing. This is a strong point of the English Electric, yet the bigger switch allows notes to stop and start more quickly and cleanly, presumably because there is less blurring of the spaces between them. Voices have distinct acoustics that often contrast with those of other instruments in a band, and this becomes easier to spot, as do the harmonics produced by acoustic instruments thanks to the big reduction in background fug.

I tried Sinatra’s ‘Fly Me to the Moon’ (Live at the Sands Hotel and Casino), which describes the quality of timing. It can sound loud and brash if timing isn’t on the money, but when you have a Tempus, keeping the backgrounds clean, it really swings, and it becomes easy to hear why the tune has stood the test of time. This switch also illustrated how much cleaner the highs are; the flute no longer shrieks but sounds open and natural. Tempus also managed to make a recent purchase sound a lot more interesting than it had previously seemed; what was bland became three-dimensional and engaging, and that, in my book, is the ultimate upgrade.

You need a decent streamer and DAC to fully appreciate the qualities that the Network Acoustics Tempus brings to the party, but nothing outrageous nor much more expensive than the switch itself, for that matter. It proves that how the signal is dealt with in its network state is just as important as how the streamer unpacks it, and the DAC converts it. Don’t think of a network switch as an optional extra. Think of it as the gateway to great streaming sound, for that is undoubtedly what Tempus is.