Daisy Chaining Intona USB isolators Topic is solved

Using USB isolation for audio
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Softsounds
Posts: 3
Joined: June 5th, 2021, 9:26 am

Daisy Chaining Intona USB isolators

Post by Softsounds »

I’m a happy user of the isolator. I am wondering if there is any benefit either technically or if you have made any measurements to show better isolation if two isolators are connected via short usb cables in series.

This is because some have reported good results with the Intona connected after a USB reclocker such as the Innuos Phoenix.

Daniel (Intona)
Posts: 72
Joined: May 6th, 2020, 8:29 am

Re: Daisy Chaining Intona USB isolators

Post by Daniel (Intona) »

Short answer: does only work with hubs in between.

Long answer: doing transparent isolation requires utilization of a complete USB packet frame (side note: this is the reason why you need 100% USB compliant hardware for both host and device). Connecting two isolators in chain would violate the packet timing and would simply refuse operation. Connecting a hub* in between acquires a new timing slot because the hub enumerates and queues all frames. So this will work again in most cases. But doing so for improving audio would touch the snake oil world. There is no technical reason why this would touch any data which is in your case: framed audio packets. If somebody told you that "reclocking" or "de-jittering" within the USB bus does something to the audio, he is painfully wrong. You only need exact timing between each sample at (1) A/D conversion time and (2) at D/A conversion time. Everything in between is just numerical data and the only important factor is that this data will not be altered in any way.
When your audio sounds better with isolation, this is because you have broken a ground loop and got rid of any noise/hum artefacts (which look like the "?" in the animated graphic here: [External Link Removed for Guests])

*btw: the Innuos Phoenix is technically a 1-port-USB-Hub. Any $5 cheap junk hub would do the same job, believe or not.
Daniel (Intona)

Softsounds
Posts: 3
Joined: June 5th, 2021, 9:26 am

Re: Daisy Chaining Intona USB isolators

Post by Softsounds »

Thanks for this enlightening explanation. I feel it’s going to save me a lot of money!

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