Fidelity Audio Hifi Upgrades

No Noise Ultra X High Frequency filter

£499.17 (ex. VAT)
NNU X Reference High Frequency Mains Purifier

The Fidelity Audio NNU X HF Mains Filter is designed with 32 filter points housed in a custom case.

2 Options Available

No Noise Ultra HF

Common mode filter (Low Frequencies) - No
Common mode filter (High Frequencies) - Yes
Differential filter - No
HF Filtering large (32 pole) - Yes
HF Filtering small (4 pole) - No
Spike Clamping - No

No Noise Ultra HF Special Edition

The Fidelity Audio NNU X HF SE Mains Filter is designed with 64 filter points (2x 32) housed in a custom case (This is achieved by adding an extra HF circuit in the case).

Common mode filter (Low Frequencies) - No
Common mode filter (High Frequencies) - Yes
Differential filter - No
HF Filtering large x2 (32 pole x2) - Yes
HF Filtering small (4 pole) - No
Spike Clamping - No

  • Start stop timing of instruments are improved
  • Quieter background / noise floor
  • Designed to work in conjunction with our other range of filters
  • Reduces High Frequency noise such as RFI / EMI
  • Operates @ 32 different frequency ranges - (times 2 for SE Version)
  • 1Khz ---> 13Ghz operating region - See below
  • Removes high frequency hash
  • High Quality Silver plated OFC cable fitted internally
  • Case internally coated in RFI /EMI reduction material
  • Ideal for larger Hi-Fi or Home Cinema systems with four or more components
  • Uses the latest technology (rapid response) clamping component
  • LED power indication
  • Dimensions – 221mm x 176mm x 58mm (LxWxH)
  • DC resistance (LN) – 200 Kohm approx
  • Weight – 1.10 Kg
Frequency points

Please note - Please allow 500 hours minimum burn in time.

fidelity audio
Product Code:
No Noise Ultra HF
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Customer reviews

(1 Customer reviews)
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Hi Brent , after approximately 100 days of the NNUXHFSE being in the system, I think the unit is getting pretty much run in . The original NNUXHF which you upgraded for me has been in the system for over 6 months. I must admit I did cogitate long and hard about whether to invest in this product ( which is your most expensive) as I did already have the NNUHF plug in and my filtration was only 3xNNUSE’s away from your reference system, and I had Russ Andrews Clarity Mains X4 plus Clarity Pro. However, the driving force was I had recently upgraded my system .

On installing it into the system the benefits in noise reduction were immediately obvious. I started by using an old audiophile mains lead , after 2 days I replaced with my third best lead (Nordost Shiva) after another week that was replaced by my second best lead (Nordost Vishnu). After 3 months the benefits were so great I sent it back to you for the SE up grade. Now that is pretty much run- in, I would agree with your comment to me a while ago that the improvements are more akin to a component upgrade that a step improvement. The gains in noise reduction are across the frequency range, smoother highs, better mid range and more low end detail. This has helped me achieve my aim of listening to large scale music near field at the volumes I like. Classical string music is much improved , it was always the thing most difficult to reproduce I have never heard it match live music in any system however expensive. All music sounds better and more detailed and somewhat like my original system 45 years ago, smoother and in particular more involving. This product really highlights how much WIFI has polluted our mains systems in recent times. The product at £1000 is expensive, but I think that in true Fidelity value for money style it gives £2000 worth of benefit.

Brian Daw February 2020