Review: Network Acoustics Muon Pro Ethernet Filter

Q: Why do you have a Network Acoustics Muon Pro Ethernet filter in your hifi?
A: Because it makes music sound better.

Here’s the thing about add-on network devices for hifi—if you can’t think of a single reason why an Ethernet filter can effect the analog output of a networked hifi, you may not know as much as you think you know.

Some people think that since the Internet works and we can print a Word doc without error, we have all the proof we need to know that Ethernet filters are snake oil. A bunch of hoo-ha, much ado about nothing. [footnote 1]

Pop Quiz: How is a computer network different from a hifi?
Hint: One has an analog output and one doesn’t. [footnote 2]

I’ve spent a few months with the Muon Pro Ethernet Filter from Network Acoustics and I have something to say about my experience. Namely, the darn thing works.

In brief, the Muon Pro is a Gigabit Ethernet capable passive Ethernet filter with a Neutrik PCB-mounted RJ45 connector on the Input side of its rectangular body and a captive 50cm Ethernet cable terminated with a Telegaertner RJ45 CAT8.1 connector on the Output side and it’s meant to sit in between your router or switch and your network-endowed audio device like a streaming DAC or network streamer.

What does the Muon Pro Ethernet Filter filter? What does it keep out of your hifi? The company’s claim is simple—noise. Of the electrical and EMI (Electromagnetic interference) and RFI (radio-frequency interference) variety.

How did I test this claim? I listened to music with and without the Muon Pro in my hifi.

Here’s my listening methodology:

  1. Listen to music played through a hifi with various review gear for more than a decade as a full-time job.
  2. Insert the Muon Pro into hifi system.
  3. Listen to music.
  4. Remove Muon Pro.
  5. Listen again.
  6. Repeat Steps 3-5 for a few months.

To fill in even more detail, sometimes Steps 3-5 took place over the course of a day and other times over weeks. In general, I find Step 4, removing the thing under review, to be more telling than Step 2. I do not partake in rapid A/B comparisons because listening to music on the hifi is about musical engagement/enjoyment which is no way even remotely related to listening for differences between sounds during rapid in and out ‘tests’.

After 3 months + of listening to the Muon Pro in systems that included the Grimm MU2 (review), Mola Mola Tambaqui (review), Auralic AIRES G1.1 (review), totaldac d1-unity (review), and the Laiv Harmony DAC (review), I found that the Muon Pro consistently offered an improvement in sound quality, with the degree of improvement varying based on the associated system in play.

And this is one important thing about add-on network devices for hifi—there’s no way of knowing what adding one will do other than Step 2, trying the damn thing out in your hifi. Which makes a review even more difficult than a component or speaker review since my findings could be very different from yours due to all kinds of factors like the amount of noise (electrical and RFI/EMI) in and around your hifi and the receiving device’s ability to deal with same.

In my systems, the Muon Pro mainly improved low level detail retrieval and provided a clearer and better defined sound image regardless of the gear in play but the degree of improvement varied based on the system.

The Mola Mola Tambaqui, sitting at the end of a 40′ run of generic Ethernet cable on the Barn’s B-Side exhibited the largest degree of improvement, while the Grimm MU2 on the A-Side sitting on the output side of the Muon Pro that was connected to my $30 TRENDnet 8-Port Gigabit GREENnet Switch with a 2M run of AudioQuest Diamond Ethernet cable saw the least amount of perceived improvement.

Is it worth it? Does the Muon Pro deliver $1600 or thereabouts worth of better? For me the answer is yes because the Muon Pro levels the playing field by filtering out noise that could/can make review gear sound worse. This approach is really no different, at least to my mind, from using the AudioQuest Niagara 3000 for all review gear on the A-Side. The Niagara also makes music sound better.

Whether or not the Muon Pro is worth the ask is a question only you can answer and only after you’ve had real time to listen through it in your system(s). Network Acoustics offers a 60-Day “Try At Home” Money-Back Guarantee to make that part easy.

1. See MBL’s Juergen Reis on Measurements & The Bigger Picture (for Patrons only)
2. If you don’t know why this difference is relevant, research “noise in mixed signal systems”

Muon Pro Ethernet Filter

Price: £1,329.17 (EX-VAT)

Company Website: Network Acoustics


  • 8-core architecture designed to work at speeds up to 1 GB/s
  • Reference standard RFI/EMI Filter: Proprietary filter system.
  • Hand-wired entirely using 99.99% high purity OCC conductors.
  • Input: Neutrik PCB-mounted RJ45 connector.
  • Output Connector: Telegaertner RJ45 CAT8.1 connector with gold plated contacts.
  • Cable Length: 50 cm
  • Construction: Hand-assembled & individually tested in the UK.
  • Enclosure Dimensions: 190 x 78 x 50 mm
  • Weight: 300 g
  • 12 months manufacturer’s warranty.
  • Free express world-wide shipping.
  • 60-Day “Try At Home” Money-Back Guarantee.