The following symptoms are seen with the Yamaha Steinberg USB (YSUSB) driver V2.1.0 or later, but are absent, infrequent, or unnoticeable with the YSUSB driver V2.0.x.

Symptom #1

Audio dropout occurs.

Symptom #2

When an application that uses ASIO and an application that uses a Windows Driver Model (WDM) driver are launched at the same time, the app that uses WDM stops playing audio.

Root cause

• To address an issue related to USB errors, we have changed to recreate the WDM device on events such as USB error or ASIO start since V2.1.0.
• This modification has solved the original issue, but causes extra resets when USB errors occur, which may make it easier to notice the audio dropouts in such cases.
• If the application does not properly handle WDM device resets, audio may stop or the application itself may crash.

How to check the cause of the audio dropout

• Open the Yamaha Steinberg USB Driver control panel and press Shift+Ctrl+A to open the "Error Info" tab, where error information is displayed.
  
  
  
  Some values displayed here are as follows:
  • TOTAL: Total of all errors
  • USBTS: Errors related to USB communication
  • RECOV: Number of times a bus reset was performed after detecting an error.
  • DPC/T: Number of times DPC latency exceeded criteria
  • dT: Time DPC latency exceeded criteria (latest available)
  • N/A: Information in the appropriate column was not recorded or could not be read.
• Of these, USBTS is the cause associated with this symptom.

Workaround

• Regarding Symptom #1, if the original cause was a USB communication error, it is impossible to completely resolve the audio dropouts by driver.
• It is necessary to check cables, hubs and other hardware, power settings, etc. one by one according to each system to investigate the cause.
• However, if the problems did not occur with V2.0.4 and you did not notice any audio dropout, then for the time being, it is suggested that you revert to V2.0.4 driver.

The differences between V2.0.4 and V2.1.1 are as follows, so there should be no change in normal use.

[V2.0.4 -> V2.1.1]

• Solved a problem in which a blue screen was caused when using the AXR4U at 96 kHz or higher in some environments.
• Now supports Yamaha RUio16-D.
• The MIDI port name now reflects a device name in applications that use the WinRT API.

Symptom #2 should be resolved by reverting the driver to V2.0.4.

Solution

In the next version upgrade, the error handling part will be reverted, while other measures will be considered for the original issue.