Recommendation for a USB Isolator that plays well with Teensy 4.1 USB MIDI at High Speed USB (480Mbit/s)

[heiko]

Hello everyone!

I am working on a project that is causing high frequency noise (sounds like coil whine?) on my studio monitors when my Teensy 4.1 is connected to any USB port.
The Teensy is sitting in a metal enclosure inside my acoustic guitar surrounded by a magnetic guitar pickup and lots of cables which I would like to blame for the source of noise, however the noise even occurs when the Teensy is powered off. The moment the USB cable is connected to the Teensy and PC the noise occurs.
I purchased a Topping HS02 USB Isolator to tackle the noise problem and cannot make it work. The HS02 works with other devices I have lying around (such as an AKAI midi controller for example) but not with the Teensy, neither in Serial mode nor in Serial+MIDI nor in MIDI. The Teensy is neither recognized by the Arduino IDE nor my DAW Reaper. I have tried to force the Teensy to run at full speed USB (12Mbit/s) without success (as suggested here https://forum.pjrc.com/index.php?th...tion-for-teensy-4-0-vs-t3-6.71267/post-314140). Additionally I have tried what was suggested here: https://forum.pjrc.com/index.php?threads/serial-midi-over-long-distance.70173/post-305543 .
(Just to note that the Teensy works perfectly fine when connected directly to the PC without the HS02 in between)

My project is depending on being low latency so I am not sure if there is any advantage/disadvantage to running at full speed or high speed USB when it comes to USB MIDI transmission. Hence my question: Can anyone recommend a working USB Isolator that plays well with Teensy 4.1 USB MIDI at High Speed USB (480Mbit/s) ?
And in case high speed USB is not necessary for my use-case I should be fine going with any "cheap" ADUM3160 as Paul suggests in this post https://forum.pjrc.com/index.php?th...the-lpuart-to-load-the-code.71472/post-315655 , right?
Or would it be more clever to invest into a USB Isolator that makes use of a newer ADUM chip (that potentially also support high speed USB) ?

/Edit: Or should I / do I need to go for a high-end industrial grade usb isolator such as the intona USB 2.0 Hi-Speed Isolator 7054-X-DK ?

I'm happy for any input you might have and thank you for reading,
Heiko

 

[PaulStoffregen]

This USB isolator is the cheapest I've found which actually works.

Hifime Hi-Speed USB Isolator v2

The Hifime High-Speed USB Isolator is designed specifically for audio and supports USB Hi-speed mode that is required by many Audio devices. It will prevent ground loops, prevent interference and protect your equipment against power surges.

hifimediy.com

Their earlier version 1 product, which looks identical, definitely did not work with Teensy 4.x so make sure you buy the "v2" version!

I dug through my huge drawer of USB cables and found it. The packaging has no marking about which model it really is, not even saying whether it's high speed or full speed. So I plugged it and did a quick test with Teensy 4.1.

My Linux desktop recognized the Teensy 4.1 at high speed.

2025-02-04T15:01:32.335267-08:00 preston kernel: usb 11-1.4: new high-speed USB device number 6 using xhci_hcd
2025-02-04T15:01:32.413246-08:00 preston kernel: usb 11-1.4: New USB device found, idVendor=16c0, idProduct=0483, bcdDevice= 2.80
2025-02-04T15:01:32.413258-08:00 preston kernel: usb 11-1.4: New USB device strings: Mfr=1, Product=2, SerialNumber=3
2025-02-04T15:01:32.413259-08:00 preston kernel: usb 11-1.4: Product: USB Serial
2025-02-04T15:01:32.413259-08:00 preston kernel: usb 11-1.4: Manufacturer: Teensyduino
2025-02-04T15:01:32.413259-08:00 preston kernel: usb 11-1.4: SerialNumber: 7911000
2025-02-04T15:01:32.425236-08:00 preston kernel: cdc_acm 11-1.4:1.0: ttyACM0: USB ACM device
2025-02-04T15:01:32.448859-08:00 preston snapd[1855]: hotplug.go:200: hotplug device add event ignored, enable experimental.hotplug

I was able to upload the LED blink sketch from Arduino IDE, without needing to press the button on Teensy. Linux kernel messages confirm detected HID bootloader at 480 speed, and also reboot to USB serial again at 480 speed.

All my tests were done with the isolator plugged into a powered USB hub, and Teensy connected to the isolator by a short cable approx 18 inches.

So far I've not done any more testing beyond this very basic usage, but it definitely is working in this simple test at 480 Mbit speed and uploading new programs works.

Just beware the older "v1" version. I tried that years ago and it definitely did not work.