Intona High Speed USB Isolator Review 
Home Theater Accessories Acoustics, EQ & Room Tuning
Written by Andre Marc   
Monday, 01 August 2016

It is no secret that digital audio transmitted via USB is not perfect. USB was never intended for high performance audio, but eventually overtook S/PDIF as the most common connection method. Virtually all digital sources components like streamers, file players, and servers have USB outputs, and no DAC manufacturer would be taken seriously in 2016 without a high quality USB input.

USB has several key advantages over S/PDIF. First, it allows the DAC to acted as the master clock, which reduces jitter and improves timing accuracy. Secondly, and probably of more interest to the average audiophile, it allows for decoding of any format, and any resolution. Everything from Redbook CD and 24 bit PCM to DSD256.

As to be expected in the audiophile market, products related to improving the sound of USB surfaced several years ago, and it continues to be a growing segment. Audiophile grade USB cables, made to higher standards, with careful attention paid to protocol standards clearly make a difference. Both the Wireworld Starlight 7 and Platinum Starlight 7 USB cables brought my system to new levels of performance. The Starlight 7 is probably one of the better deals in digital cables. I also have had excellent sonic results with DH Labs USB cables. But other product categories aside from USB cables have also garnered much attention.

The cottage industry of USB “enhancement” devices is becoming crowded, with manufacturers claiming they have identified many of the technical issues with USB and have found unique ways of fixing these problems. What many of these devices purport to do is regenerate a fresh new USB stream to the DAC, filter any noise, and isolate the DAC from a potentially noisy source. Because USB carries with it a 5V power stream, it is not hard to imagine that filtering, isolating, and regenerating the data stream would have benefits.

Among the more publicized products to hit the market are the UpTone Audio REGEN, the Wyrd 4 Sound Recovery, the Schiit Audio Wyrd, the Audioquest Jitterbug filter, the iFi iPurifier. IFi also makes the Micro iUSB 3.0, which I reviewed recently, along with the Gemini USB cable, which physically splits the power and data leads. The iUSB worked as advertised, improving the sound as described in the review.

Well, there is a new USB enhancement gunslinger in town, and it comes courtesy of Intona, a company based in Germany thatprovides high-end digital signal processing solutions. The Intona High Speed USB Isolator costs about $360 shipped from Germany, a bit less than the iFI iUSB 3.0, but more than the Uptone REGEN and others.

Intona claims their design has the following benefits and design features:
  • Provides galvanic isolation to the USB bus
  • Compliant to USB 2.0 Hi-Speed (480 MBit/s)
  • Backwards compatible to Full Speed and Low Speed
  • Isolation withstands up to 2.5kVRMS
  • Works out of the box, no drivers needed
  • Compatibility to all operating systems, embedded systems and devices
  • Supports all USB-specific transfers and modes
  • Powered by USB bus, no separate power supply
  • Ultra-quiet power rail isolation, linear regulation
  • Connectors: host-side USB-B; device-side USB-A
  • Impedance controlled high-speed circuit design
  • National compliances: FCC, CE, RCM, ICES-003
  • Engineered and manufactured in Germany

The High Speed USB Isolator comes in two flavors: standard or industrial. The industrial version has a higher level of isolation, and is made with higher retention connectors. To the best of my knowledge there is no price difference, so I can’t imagine an audiophile not ordering the industrial version. 


There are a few options as well. The case can be ordered in black, in a resin hardened case for more challenging environments, and you can choose a solid LED light over a blinking one to indicate high speed transfer. Mine was requested with a solid LED.  Intonta designed the Isolator for a number of applications, including:

  • Industrial automation systems
  • Measurement devices
  • Environments requiring safety insulation
  • Machine protection
  • Broadcast and Studio
  • Audiophile-grade home systems  
  • All applications requiring clean and stable USB connections with separate grounds

Set Up & Listening

The Intona was used in the main system between a Bryston BDP-2 server and BDA-3 DAC. An iFI Gemini USB cable ran from the BDP-2 into the Intona, then a Wireworld Platinum Starlight 7 USB cable ran from the Intona into the BDA-3. That was it. The intona is hub powered, so no other considerations came into play. After that I picked up my iPad Air and selected music, as I would any other day.

I was a surprised that I heard an immediate improvement. Normally, it takes some time to determine if what one is hearing is just different, or really is better when using any sort of USB enhancement device. I also wanted to make absolutely sure that I was not suffering from positive expectation bias. After going back and forth for weeks with the Intona in the signal path, I was convinced I was enjoying the sound more with the Intona in tow. I even briefly used it with the wonderful CLONES Audio Asher DAC to see if I would get the same results, and I did.

I listened to recordings of all genres and vintages over the review period to see if the Intona was consistent regardless file type and resolution. It was. It made long listening sessions that much easier, and never called attention to itself. In fact, when removed from the system, it was noticeable immediately. It was the same music, but a bit of delicacy and nuance disappeared.

For the first time, I felt that USB out of the Bryston BDP-2 sounded as good as AES/EBU, This really was great news as, although the AES/EBU input on the BDA-3 DAC allows for optional upsampling, it cannot pass on DSD, and with about a thousand ripped DSD albums ripped from SACDs to DSF in my library, USB is essential.

Itona USB highspeed isolator


I admit to previously not being totally in love with USB audio. It always sounded fine for a while, then inevitably I would notice an artifice that became annoying. AES/EBU seemed to sound more natural to my ears. But in the past year or so, with devices like the iFI iUSB 3.0 and others, and with properly terminated and spec’d USB cables, I no longer feel it is a compromise. To be fair, DAC designers have greatly improved their USB inputs and and there are more and more devices coming to market with higher quality USB outputs.

Ultimately, you want your source and DAC to communicate with a clean signal path, but you do not want the source to pass on any jitter, noise, or other artifacts which will detract from musical enjoyment. The Intona High Speed USB Isolator is a device that does exactly that by creating a new USB stream and isolating your source and DAC from each other. I can’t think of a single negative about the Intona device. Without a doubt it improved the sound of my system, not just changed it. While it is not as cheap as several other similar devices, it is made in Germany and does not require a power supply.

Highly, highly recommended.


Intona High Speed USB Isolator: ~$360 USD (shipped from Germany)

Review System 1

Preamp: Aric Audio Unlimited
Amplifier: Audio Research VS55, Simaudio 760A
Speaker:  Bryston Mini T
Cables:, Wireworld, iFi
Accessories: Symposium Rollerblocks and Svelte Shelves, Shakti Stone, Bryston BIT-15, Salamander rack

Review System 2

Music Server: Sonore microRendu
Preamp: Aric Audio Expression
DAC/Streamer: Simaudio 280D
Power Amplifier: Onkyo M5000R
Tape Deck: Sony TC-350
Speaker: Magnepan MMG, Spendor S35R
Cables: Wireworld
Accessories: Cable Pro Noisetrapper, iFi iPower, Audience aR6

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