AVB Monitor 8 - USB 3.2 Gen 2 Not Working

[kevinjmcmahonjr]

I got a new mini PC which has two USB 4 Ports, four USB 3.2 Gen 2 Ports and 1 USB 2.0 Port.
It has a Ryzen 7 7840HS, 1TB NVME, 32GB DDR5 5600mhz RAM Plenty for basic recording.

I installed my AVB Monitor 8 on it. It connects fine and Windows 11 sees it. I can open the mixer and see levels on inputs.

However, no audio level come from the computer and no audio level go to the PC. I thought it was just WDM driver doing something stupid so I opened my DAW and tried to get anything to work there. Again, the DAW sees the interface and recognizes the inputs, but no signal in or out.

I thought something might have been messed up in the routing so I wasted an hour trying old presets I had made, clearing them and doing them again. I'm just thinking I'm doing something stupid.

Finally I decide to try a different USB port. I did not have a USB C to USB B cable so I just decided to plug it in the only USB 2.0 port that happens to be on the computer and everything started working.

I'm surprised at this as for a while MOTU was advertising USB 2.0 but fully compatible with USB 3 and I had run it on USB 3 ports on at least 3 other computers with no issues. I thought this issue was a thing of the past. I remember around Windows 7 days and early USB 3 days this was a big thing, but it seems to have been ironed out. Minor annoyance because the USB 2 is on the front...

I'm wondering if anyone else is having this issue still. Maybe it's a USB 3.2 Gen 2 specific thing or just the specific chipset the computer is using.

[mikehalloran]

MOTU claims that USB 3 is compatible with USB 2 on one of their pages. This isn’t true. They are separate protocols. Here are the specs for the Monitor 8:

USB 2.0 (44.1 to 48 kHz): 64 in/out
USB 2.0 (88.2 to 96 kHz): 32 in/out
USB 2.0 (176.4 to 192 kHz): 24 in/out
AVB Ethernet: 16 to 128 in/out, depending on
host computer speed

Nowadays, most computers use a USB controller that supports both protocols—yours probably does. However, your cable also needs to support USB 2 and many USB-C cables do not.

This is a big problem with office printers and USB Printer Cables that support USB2/1.1 only now exist. Yamaha now recommends using these to ensure compatibility for their keyboards and interfaces. If your 3.2 ports support 2/1.1, this cable will fix you up.

https://www.amazon.com/CableCreation-P ... r_1_1_sspa

If it doesn’t, the problem is your computer.

[kevinjmcmahonjr]

Well, not exactly, I fully understand that USB 3 and 2 are different protocols and what is listed on the product specs on Motu's website. However, when Motu first released the AVB line, one of their marketing points was that it was USB 3 compatible. Still listed on the product page's marketing portion.

Screenshot 2025-04-17 113930.png (342.4 KiB) Viewed 736 times

I understood that as the interface was operating under the USB 2 protocol, but they had found some way for it to work with USB 3 ports to just work without hitches. Perhaps that wasn't true or I am misinterpreting the information. At the time, I had other interfaces that had trouble with USB 3 ports that the Monitor 8 no longer had. This is already 10-ish years ago, but it is where my assumption comes from. I also haven't had any issues with new computers since then I kind of just figured the USB spec was ironed out (at least for audio, because it's all over the place).

The USB 3.2 Gen 2 ports on this computer are all regular USB-A ports. Only the USB 4 ports are USB-C. The cable I'm using is a regular USB 2.0 cable. Same cable, USB 3.2 Gen 2 port no audio passes between the interface and computer but I can control the interface and see level from inputs, plug it into the only USB 2.0 port the computer happens to have and it all works fine.

Perhaps this computer's USB 3.2 Gen 2 ports have something about them that are preventing the USB 2 protocol to work correctly. But based on my past experience I thought this was all straightened out. Mind you I went through Windows XP through 7 era, the 32 to 64 bit era, the USB 2 to 3 era with several interfaces PCI to PCI-e to Firewire to USB 2 and USB 2 but on USB 3 ports. That's why I'm kind of surprised, this type of issue has completely been absent for me for 10-ish years over several different computers and interfaces.

Just seeing if anyone else has had a similar experience for me and knows if there is something with USB 3.2 Gen 2 specifically or perhaps a fix or perhaps an incompatibility chipset list to cross reference to see if my computer has one that's just not compatible or if there's a special USB driver to install instead of the default.

[mikehalloran]

Well, not exactly,

Screenshot 2025-04-17 113930.png

Yes exactly. I'm a longtime member of the USB IF where USB 3 is best described as a Hot Mess — and we set the standards.

That page is flat out wrong and written by Marketing — it assumes that modern PCs support both protocols in all ports but that assumption is not always correct. Since I don't have your machine on my bench, I'm still assuming that yours actually does—but it is only an assumption. There's an easy way to find out.

A compatible cable must include the wiring for USB 2 and many don't—the only common connector for both protocols is the ground. If a USB Printer cable shows the Monitor 8 in your 3.2 ports, then that was the problem. If you don't see it, your computer is the problem and connecting to your USB-A port is your only solution.

There is no driver or firmware that can enable USB 2 on a computer port if the controller that doesn't support it. Likewise, there's no way to enable USB 3 on the Monitor 8 since that hardware only supports USB 2.

You can believe this from MOTU.

USB 2.0 (44.1 to 48 kHz): 64 in/out
USB 2.0 (88.2 to 96 kHz): 32 in/out
USB 2.0 (176.4 to 192 kHz): 24 in/out
AVB Ethernet: 16 to 128 in/out, depending on
host computer speed

Most USB 4 cables support both protocols, too including this:
https://www.amazon.com/dp/B0BQ1Y4KQZ?re ... in_title_8

Having a MOTU MTP AV USB, I can test backward compatibility to USB 1.1 and this cable passes.