Designed for purity

The SmoothLAN sits between your home network and Hi-Fi system and is designed with one purpose: to eliminate crosstalk and interference and remove potential sources of parasitic noise affecting the system.

Counteracting noise and improving the timing of digital signal transmission are essential steps towards bringing the best out of your Hi-Fi.

How it works

Rather than using one unit to isolate all signals, the SmoothLAN focuses on locally isolating the network input into the Hi-Fi system. This advanced design minimizes crosstalk and effectively reduces interference, ensuring a cleaner signal. 

Designed specifically for use with music streamers and capable of handling data speeds up to 100Mbps, the SmoothLAN takes network filtering a step further by integrating six isolation circuits which are individually enclosed within an aluminium case, establishing distinct boundaries. This shielding not only prevents interference between components but also safeguards against performance degradation caused by external vibrations.

More than just a filter

The SmoothLAN is the result of a careful and deliberate design process, with each decision contributing to its overall performance.

  • Precision machined aluminium case features fully shielded pockets which serve as barriers, isolating the electronic components from each other and external disturbances.
  • EMI absorbing materials embedded inside the pockets further neutralize noise reflections from the components.
  • Perfectly sealed enclosure using 20 screws to ensure there are no gaps between the shielded pockets that could compromise performance by amplifying specific frequency ranges.
  • Discrete components enable high-speed traces (the signal paths on the circuit board) with incorporates ground planes/shields between them. optimizing signal paths for superior performance.
  • Optimized Grounding to minimize crosstalk. Each circuit on the PCB is surrounded by copper grounded to the case. This creates an effective shield against interference and ensures return currents do not interfere with neighbouring circuits.
  • Galvanically Isolated to ensure the breaking of ground loops by preventing unwanted current from flowing between two units sharing a ground conductor.

Precisely Engineered

Built entirely in the UK, the Stack Audio SmoothLAN employs high-specification materials and components. This aligns with Stack Audio’s philosophy, dedicated to delivering products that not only showcase premium quality and performance but also provide excellent value for money.


A cable cannot enhance an audio signal. Instead, the aim is to preserve the signal purity and suppress interference. Our connecting cable is designed to safeguard the purity of the Ethernet signal between the SmoothLAN filter and the music streamer. The supplied cable is an oxygen free copper, CAT 7 cable, with gold plated connectors.

Size: 104x40x21.5mm

Weight: 200grams

Speed: Designed specifically for use with music streamers and capable of handling data speeds of up to 100Mbps.

Cable length: 25cm

Available in a choice of Black or Silver

30-day money back guarantee

One week lead time currently advised due to high demand.

Price: £200 EX-VAT

Customer Reviews

Chris Baillie reviews the SmoothLAN for The Ear
"If you have a high-quality, wired network streaming system for music and video, then Stack Audio’s 30-day, no-quibble money-back guarantee makes a purchase of this clever device the proverbial no-brainer."
Alan Sircom reviews the SmoothLAN in the March edition of Hi-Fi+
"So, the question is, does the SmoothLAN justify its place between the switch and the network player? Absolutely."
Chris S. – Australia
"The SmoothLAN is delivering like a product worth 20 times its price, it's like when I swapped out the XPS DR for the 555PS DR!"
Thomas J. – Sweden
"Normally I search intensely for SQ parameter improvements. Not this time! I found myself enjoying the music, being completely relaxed and nearly hypnotized for hours."
Leslie H. – UK
"Great product for the money, highly recommended for those who like a clean, clear and open sound free from parasitic noise."
Preben D. – Sweden
"In my setup, the SmoothLAN is shockingly good. My overall thoughts are that I am able to hear the full potential of my system for the first time."
Mark K. – UK
"The difference the SmoothLAN makes if night and day. Vocals are crystal clear, midrange is definitely improved. As for bass, hold on to a set. WOW."
Kelvin C. – USA
"I thought I would have to do some A/B listening to appreciate the SmoothLAN. Not so much. Immediately noticed more 3D in the high end, and a notable increase in instrumental separation and body."
David F. – UK
"I could hear a significant difference with the SmoothLAN in my chain, without a doubt the best my system has sounded."
Colin H. – UK
"The vocal sibilance I was noticing before has dissapeared! I am delighted. Only positive improvements noticed at the moment."


We recommend you start by connecting it directly to your streamer which should work best for most systems. However, as home networks and hi-fi systems vary, you may want to experiment by placing it next to or between other components in your network (for instance by your router).

The amount of interference and noise on home networks will vary depending on the cable layout, the number and proximity of noisy electrical devices both in your own home and neighbouring properties. This can also vary depending on the time of day and operation of noisy devices.

Some Ethernet filters use plastic to prevent case interaction with internal magnetic fields, but this leaves the device susceptible to external interference, which is likely even stronger. In contrast, our aluminium case, coupled with a compartmentalized design and EMI absorbing material, provides superior shielding not just from external electromagnetic interference but also isolates internal magnetic fields from each other.

No. The SmoothLAN can be used in either direction as Ethernet by its nature is a two-way signal.

  1. Power down the device that will be connected to the network via the filter.
  2. Unplug the Ethernet cable from your device’s network port.
  3. Insert the unplugged Ethernet cable into one of the ports on the SmoothLAN Network Filter.
  4. Take the additional Ethernet cable provided with the filter and connect one end to the second port on the filter.
  5. Connect the other end of the additional cable back into the network port of your streaming device.
  6. Power up your device, and it should now be properly connected through the SmoothLAN Network Filter.
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