It’s hard to avoid basic switch mode power supplies in streaming systems, they power every mainstream element in the system from the router through to the NAS drive and gigabit switch. Cheap switching supplies are marvels of technology, compared with linear types they use very little power and don’t get hot as a result. But they send noise both to the component they power and back into the mains, and this undermines the quality of hi-fi systems that share that circuit.
Fortunately these supplies are housed in a wall-wart plug so it’s possible to replace them with a linear power supply, and this is what MCRU has commissioned LDA (Longdog Audio) to build. They make a big one called XLCR that I reviewed with a Naim Unitiserve last year, and it managed to significantly improve on the better than usual supply designed for that piece of kit. Now there is a smaller model for routers and switches that is built into two permanently connected boxes with a good quality plug for power delivery. There are two boxes because the regulator for the load needs to be as physically close to it as possible, whereas the mains transformer acts as a barrier to noise. LDA’s Nick Gorham explains, “its job is to take the incoming mains and convert it into a low(ish) noise DC supply, and to isolate the mess that is our household power lines from what follows… The regulator in the smaller box therefore gets a clean, low noise supply with which to handle the demands of the load (in this case the switch/router)”.
I tried it on a Netgear GS108 gigabit switch that sits between my router and the streamer and, on this occasion, three alternative NAS drives. The quality of the drive had a clear bearing on the degree of improvement that this supply delivers. But in each case that improvement was obvious, and unsurprisingly greatest with the least audio oriented drive, a WD MyBook Live. This sounds pretty coarse on its own but gains depth and better timing with this supply, it also gets cleaner and thus easier to enjoy in a revealing system. If I were using the WD for most of my listening it would be an essential upgrade.
With a Naim Unitiserve the change was more subtle, space and depth once again increase and reverb is considerably easier to appreciate, all of which comes down to a lower noise floor. Again a definite bonus. The final comparision was with the Melco N1A which is a very quiet digital store already and doesn’t actually need an outboard switch, however when running through the Netgear changing to the LDA linear supply rendered the sound brighter, cleaner and more open, essentially it freshened it up. So a different but nonetheless beneficial result.
The obvious next step for those using a conventional NAS is to get a linear supply for that, At present MCRU doesn’t have one for that purpose because the likely current draw is higher than the 1.5 amp max available from this unit. David Brook at MCRU says that the only suitable model they have is the same one sold for the Unitiserve, which is a bit pricey for this job.
This compact piece of kit will benefit most any mid to high end streaming system either by using it on the router or the switch (and probably both). It may be possible to find another linear supply for less than the price asked here but in my experience LDA products tend to sound better than mainstream alternatives and last longer.
Specifications
Voltage: 12V DC
Maximum amperage: 1.5 A
Size HxWxD: 55 x 105 x 165mm (main unit)
Price £235
MCRU
www.mains-cables-r-us.co.uk