Hardware Reviews

Muon Pro for ultimate streaming

network acoustics muon pro streaming system

Network Acoustics Muon Pro Streaming System ethernet filter and data cable

Long before anyone dreamt of a device like the Muon Pro it was assumed that the music data heading for our streamer was just that. To suggest that it might be accompanied by electronic pollution that was damaging to sonic performance was to invite the burning coals of Hades to be heaped upon our heads by keyboard warriors that knew better. It’s just noughts and ones, right?

Today, thanks to thick-skinned pioneers like Network Acoustics, we can hear unequivocal evidence of the sonic harms caused by high frequency interference on the data feed to our streamer. The proof comes in a straight forward A/B comparison. Play a track. Now put a Network Acoustics filter in between the ethernet wall socket and the streamer and play the same track. As a number of my reviewing betters have already reported, there’s no going back. Our Editor here on The Ear, Jason Kennedy, reviewed the 100 Mbit/s Muon Streaming System in June 2022 and declared: “…anyone wanting to hear the full potential of their system should invest in one before considering other upgrades.”

The Muon that Jason and other reviewers rated so highly has now been superseded by an enhanced version, the gigabit Muon Pro. At £1,594 for the stand-alone filter or £2,295 including a 1.5m Network Acoustics ethernet cable (together Network Acoustics calls them the Muon Streaming System), there’s no getting away from it; the price of improved streaming with Network Acoustics is stiff. Especially if we regard paying, say, £1,800 for Lumin’s U2 Mini, as an extravagant use of household funds. On the other hand, if we’ve coolly dropped some £5,000 on an Auralic Aries G2.1 or some such, or – and let’s really lose our heads – £11,000 on a Grimm MU1, then proportionally the price of the Muon Pro might assume, er, a different proportion.

Secret ingredients

Network Acoustics’ Richard Trussell won’t say exactly what’s inside the Muon Pro ethernet filter, and due to its welded ABS construction without a removeable lid I was unable to investigate the contents without terminally violating the review sample. However, what Trussell did venture is that the technology mops up unwanted high frequency noise that results from RFI and that we can think of it as a form of grounding. It provides a path whereby high frequency noise is led away and dissipated, leaving the music data untouched.

network acoustics muon pro streaming system

Network Acoustics says both the router and network switch are the primary sources of RFI, due in part to the cheap-as-chips switching power supplies that they use. The company suggests the Muon filter is therefore placed between the streamer and the switch so that it mops up the RFI from both of the sources, with the 1.5m (longer can be specified) Muon Streaming System cable taking the data the last hop to the streamer.

I questioned the wisdom of placing what is effectively a 1.5m aerial after the filter. Surely it would be better to deploy the filter as close as possible to the streamer? Trussell noted the point. “It was the configuration we initially thought was correct. The instructions for the original ENO and Muon filters suggested exactly that, however some customers preferred it the other way round, putting the filter before the Streaming Cable. We tried it, and it did indeed sound a bit better in our systems. Therefore, for Muon Pro we suggest this way round for best results, but the Muon Pro Filter is not directional so people can experiment in their own systems for best results.

“We don’t believe that the ‘air born’ RFI in the last 1.5M of Streaming Cable after the filter has any significant effect in most systems, and that what is more significant is the effect of the length of the Streaming Cable after the filter, in terms of reflections and interference of the ethernet signal in the conductor. That’s why the cable is 1.5M, anything below that suffers from reflections and this effects sound quality.”

Reviewers confronted with the first version of the Muon reported being shocked at the scale of the improvement in sound quality that it liberated from a variety of streamers. Partly out of devilment and partly because at the time it was the only streamer that I had to hand, I tried the Muon Pro with my Grimm MU1. Grimm Audio say that fancy ethernet cables are not required with the MU1 and that any regular lead will do. I was therefore not expecting much improvement, if any.


Clearly, the Muon Pro Streaming System had not read the Grimm user manual because its substitution for the regular RJ45 computer lead that I had been using resulted in a highly satisfactory, if not wholly revelatory, jump in the MU1’s sonic performance. This finding needs to be set in context. Grimm Audio’s incredible attention to detail in the MU1’s power supply, re-clocking and data processing have created what I regard as the streamer to beat at its price point and some margin beyond. I thought so much of it that I bought the sample that I got in for evaluation and subsequent review, and went on to propose it for one of The Ear’s 2022 Best of the Year Awards. Nevertheless, should we be wholly surprised that even the very good can be made better still by thoughtful augmentation? Probably not. Thus it was that the Muon Pro Streaming System made its case to be partnered with the MU1. Immediately noticeable was a drop in background hash and an increase in tonal, dynamic and spatial detail.

I played the opening track, Free, on pianist Alex Bugnon’s 2005 album of the same name. I paused the track, re-inserted the standard RJ45 lead, and set the track playing again from the start. No doubt about it; the gains noticed moments before had now become losses, and it was also clear that Bugnon’s piano – not that well recorded on this particular album – sounded marginally thinner, and with a subtle but still noticeable intermodulation component to the higher ranges.

Almost probably

Re-installing the Muon Pro Streaming System, the listening session turned out to be somewhat longer than I had anticipated due simply to the fact that I was enjoying the sound more. Of all the streamers that I’ve had through my hands in the past two years the MU1 had impressed as the best of the bunch, bettered only in some aspects by a UK-built alternative that retails north of £25,000. Had the Muon system bridged the gulf between the two? Almost probably. Sorry if that’s annoyingly equivocal but I’d need to hear the much more costly streamer again to be sure.

network acoustics muon pro streaming system

The easier question is, if the Muon Pro has a beneficial impact on the sonic performance of an extremely competent high-end streamer such as the Grimm MU1, what might it do for a modestly-priced one such as the aforementioned Lumin U2 Mini, or perhaps the iFi Zen Stream at £400?

To find out, I took the Muon Pro on tour, visiting two homes with contrasting streaming set-ups, the first a Linn system in which the DSM had been upgraded with a Katalyst DAC board; the second home having a Lumin U1 Mini, predecessor to the current U2 Mini. The impact of the Muon Pro on both systems was profound, much more so than on the Grimm MU1. All the gains noted with the Grimm streamer were present, but heightened, almost as if a hidden hand had dialled them up to 11. When in the first home the Muon Pro was disconnected and put back in its box, the householder waved his hand at his system in despair and dismissal: “Ugh. Horrible. I just can’t listen to that now.” Jason and the other reviewers who evaluated the original Muon will no doubt nod their heads in understanding and sympathy.

Muon Pro verdict

Network Acoustics is not the first vendor with ‘can’t go back’ technology, but that doesn’t make the Muon Pro ethernet System any less of a stand-out product. I would be willing to bet that the company, offering a 30-day money-back trial, sees very few, if any, returns.


Muon Pro ethernet filter
Type: Silver wired 1GB/s ethernet filter
Input: 50cm UP-OCC continuous cast pure silver ethernet cable
Output: Neutrik RJ45 ethernet
Termination: Telegärtner RJ45 CAT8 connector
Size HxWxD: 50x190x78mm
Warranty: 2 years

Muon Pro Streaming Cable
Type: 8-core 1GB/s ethernet network cable
Conductor: UPO-OCC continuous cast silver
Length: 1.5m
Terminations: Telegärtner Cat8.1 wide bandwidth gold plated connectors
Warranty: 2 years

Price when tested:
Muon Pro filter £1,595 (£1,329.17 without VAT)
Muon Pro Streaming System £2,295 (£1,829.17 without VAT)
Manufacturer Details:

Network Acoustics
T +44 (0)2380 615 627


gigabit ethernet streaming filter


Kevin Fiske

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