This is a review and measurement of Intona USB Isolator. In the last few years there has been a proliferation of USB filters, cleaners, regenerators, feeding on fear of audiophiles of noisy computer ports. Intona doesn't actually play in that market directly. They built this device for industrial control applications where strict isolation from the machine being controlled is required. Audiophiles however, have been interested in the unit just as they are in other devices in this category.
This unit is on a kind loan from a forum member. It retails for USD $229 plus $29 shipping to US. It comes in a nondescript, plastic box. No pretense of being a audio jewelry here. For this review I compared the Intona to Uptone Regen and TotalDAC D1. You can see the full collection here:
Interestingly the Intona works without any external power even though it is an active device. The Uptone Regen which is also active needs an external power supply which itself can be a source of noise (I used the iFi iPower supply that was recommended for it). I think the TotalDAC is passive but I am not sure. Either way, it doesn't need a power supply.
Let's get into measurements and see how they do. If you are not familiar with my tests, I suggest reading my tutorial on audio measurements here: https://www.audiosciencereview.com/forum/index.php?threads/understanding-audio-measurements.2351/.
Measurements
Wanting to get positive results, I reached out for a DAC that I know lets USB noise bleed into its output: the Schiit Modi 2 Uber. From past testing I know that J-test of jitter and noise is very revealing of what these devices do or don't. So I hooked up the Modi 2 Uber to my HP Z series Laptop, fired up Roon to play the J-Test signal to it and measured what comes out of the DAC. Anything other than the main tone at 12 kHz is unwanted:
Focusing on the naked Modi 2 Uber, we see that we picked right. The broad shoulder below and around our tone indicates low frequency, random jitter. In addition we see that it produces those spikes in yellow to the left.
The graph in red is with addition of Intona. We see that it nicely cleans up all the lower frequency distortion spikes. It does nothing for random jitter as that is likely created inside the Modi 2 DAC.
So objectively speaking, the Intona USB Isolator does its job, providing a cleaner signal to Modi 2 which in turn generates cleaner output.
Let's switch to Uptone Regen and see what it does:
That is a bummer. Not only does it not remove any distortion products, it adds its own at 8 and 16 kHz! The Regen has a USB hub in it and seemingly it allows the 8 Kbyte USB packet interval to become much stronger. We definitely took a step backward here. The Uptone Regen is $175 and the iFi Power supply is another $50 so the total cost is the same as Intona.
Next let's examine the TotalDAC D1. I have reviewed the totaldac D1 before. This is another take on it with our new setup here:
This is essentially the same outcome as Regen. Nothing is filtered and we have a new spike at 16 kHz. Seeing how this is the most expensive of the three at €390 or USD $480, this type of performance is super disappointing.
Enough with low-end DACs. Let's put the Intona in front of the RME ADI-2 DAC and see what happens:
As we see in yellow, there is nothing to be fixed and performance is at the limits of my measurements. The Intona adds a bit of noise to low frequencies. Not sure what it is about but it is extremely small.
Conclusions
The Internet is full of praise for these USB filters. The imagination works wonders here, equating USB and computers with noise, and assuming anything that filters it must make things sound better. That predisposition makes one perceive improvement even if it is not there.
Noise is easily measured as see above. So people should not assume a device is a true filter without seeing it actually measured as such. Based on this work, and confirmed by previous measurements I have performed, neither the Uptone Regen nor the TotalDAC D1 filter anything. Instead, they add their own noise components. Mind you, the addition while measureable, is not audible so no wonder no one is complaining about it. If you want to dismiss objective data on these products you can. But please go into any subjective review assuming that it could also do nothing versus "must be filtering."
It is in this context that I smile when I see the performance of the Intona USB Isolator. Finally a USB filter that actually filters! So congratulations to Intona for building a proper product that reproduces the USB bus cleanly.
Alas, as I have shown with RME ADI-2 DAC, you do not need USB filters. The solution to Modi 2 Uber noise and distortion is to buy a DAC at the same price or lower that doesn't have these issues. Schiit products seem to be sensitive to quality of USB power. Better designed DACs don't have that problem.
-----
As always, questions, comments, recommendations, etc. are welcome.
If you like this review, please consider donating funds for these types of hardware purchases using Patreon (https://www.patreon.com/audiosciencereview), or upgrading your membership here though Paypal (https://audiosciencereview.com/foru...eview-and-measurements.2164/page-3#post-59054).
This unit is on a kind loan from a forum member. It retails for USD $229 plus $29 shipping to US. It comes in a nondescript, plastic box. No pretense of being a audio jewelry here. For this review I compared the Intona to Uptone Regen and TotalDAC D1. You can see the full collection here:
Interestingly the Intona works without any external power even though it is an active device. The Uptone Regen which is also active needs an external power supply which itself can be a source of noise (I used the iFi iPower supply that was recommended for it). I think the TotalDAC is passive but I am not sure. Either way, it doesn't need a power supply.
Let's get into measurements and see how they do. If you are not familiar with my tests, I suggest reading my tutorial on audio measurements here: https://www.audiosciencereview.com/forum/index.php?threads/understanding-audio-measurements.2351/.
Measurements
Wanting to get positive results, I reached out for a DAC that I know lets USB noise bleed into its output: the Schiit Modi 2 Uber. From past testing I know that J-test of jitter and noise is very revealing of what these devices do or don't. So I hooked up the Modi 2 Uber to my HP Z series Laptop, fired up Roon to play the J-Test signal to it and measured what comes out of the DAC. Anything other than the main tone at 12 kHz is unwanted:
Focusing on the naked Modi 2 Uber, we see that we picked right. The broad shoulder below and around our tone indicates low frequency, random jitter. In addition we see that it produces those spikes in yellow to the left.
The graph in red is with addition of Intona. We see that it nicely cleans up all the lower frequency distortion spikes. It does nothing for random jitter as that is likely created inside the Modi 2 DAC.
So objectively speaking, the Intona USB Isolator does its job, providing a cleaner signal to Modi 2 which in turn generates cleaner output.
Let's switch to Uptone Regen and see what it does:
That is a bummer. Not only does it not remove any distortion products, it adds its own at 8 and 16 kHz! The Regen has a USB hub in it and seemingly it allows the 8 Kbyte USB packet interval to become much stronger. We definitely took a step backward here. The Uptone Regen is $175 and the iFi Power supply is another $50 so the total cost is the same as Intona.
Next let's examine the TotalDAC D1. I have reviewed the totaldac D1 before. This is another take on it with our new setup here:
This is essentially the same outcome as Regen. Nothing is filtered and we have a new spike at 16 kHz. Seeing how this is the most expensive of the three at €390 or USD $480, this type of performance is super disappointing.
Enough with low-end DACs. Let's put the Intona in front of the RME ADI-2 DAC and see what happens:
As we see in yellow, there is nothing to be fixed and performance is at the limits of my measurements. The Intona adds a bit of noise to low frequencies. Not sure what it is about but it is extremely small.
Conclusions
The Internet is full of praise for these USB filters. The imagination works wonders here, equating USB and computers with noise, and assuming anything that filters it must make things sound better. That predisposition makes one perceive improvement even if it is not there.
Noise is easily measured as see above. So people should not assume a device is a true filter without seeing it actually measured as such. Based on this work, and confirmed by previous measurements I have performed, neither the Uptone Regen nor the TotalDAC D1 filter anything. Instead, they add their own noise components. Mind you, the addition while measureable, is not audible so no wonder no one is complaining about it. If you want to dismiss objective data on these products you can. But please go into any subjective review assuming that it could also do nothing versus "must be filtering."
It is in this context that I smile when I see the performance of the Intona USB Isolator. Finally a USB filter that actually filters! So congratulations to Intona for building a proper product that reproduces the USB bus cleanly.
Alas, as I have shown with RME ADI-2 DAC, you do not need USB filters. The solution to Modi 2 Uber noise and distortion is to buy a DAC at the same price or lower that doesn't have these issues. Schiit products seem to be sensitive to quality of USB power. Better designed DACs don't have that problem.
-----
As always, questions, comments, recommendations, etc. are welcome.
If you like this review, please consider donating funds for these types of hardware purchases using Patreon (https://www.patreon.com/audiosciencereview), or upgrading your membership here though Paypal (https://audiosciencereview.com/foru...eview-and-measurements.2164/page-3#post-59054).