H9000 USB audio – frequent dropouts

Hi, I’ve totally failed to get USB audio working with the H9000. Upgrading to latest firmware (2.1.14[144]) does not help.

It sometimes passes audio, but with frequent dropouts lasting about 200ms, recurring every 5-30 seconds, this is unusable. I’m trying USB audio alone, no aggregate device — the goal is to get USB audio alone working smoothly before attempting to combine with another interface.

I have no such problems with my Lynx Aurora (n) — 24 channels.

I am using the “H9000 USB Audio” port in Audio Midi Setup (AMS) with clock source “Eventide Internal Clock”, sample rate 48 kHz I also have this port selected in the Logic session.  When beginning, I toggle the sample rate in AMS from 44.1 back to 48 to cancel the “USB Audio Mute” message. When running, and when I experience the dropout, USB audio is not muted.

The problems also do not change if I use different buffer sizes (64-512) or settings for processing threads. I can reproduce the issue in a very minimal Logic project with four stereo channels, zero plugins etc.

If I do have a native plugin running in Logic, for instance Autofilter, I notice that after recovery from dropout the plugin’s LFO phase resets. This seems to indicate that something in the Mac audio engine is restarting each time there’s a dropout.

I caught some of the Mac console messages during dropouts,

The first such message is from kernel: IOAudioEngine[<private>]::pauseAudioEngine()

Immediately after I get a more detailed message from coreaudiod that there has been an overload: coreaudiod Audio IO Overload thread: 37d1 inputs: ‘<private>’ outputs: ‘<private>’ cause: ‘Unknown’ prewarming: no recovering: no

Then an info list – the cause of the overload is “PageFaultsOffIOThread:”

coreaudiod     CAReportingClient.mm:508   message {

HostApplicationDisplayID = “com.apple.logic10”;

cause = PageFaultsOffIOThread;

deadline = 123007;

“input_device_source_list” = Unknown;

“input_device_transport_list” = USB;

“input_device_uid_list” = “AppleUSBAudioEngine:Eventide:H USB Audio:0:1,2”;

“io_buffer_size” = 256;

“io_cycle” = 477;

“io_page_faults” = 0;

“is_prewarming” = 0;

“is_recovering” = 0;

“issue_type” = overload;

lateness = “-285”;

“other_page_faults” = 42;

“output_device_source_list” = Unknown;

“output_device_transport_list” = USB;

“output_device_uid_list” = “AppleUSBAudioEngine:Eventide:H USB Audio:0:1,2”;

“sample_rate” = 48000;

“smallest_buffer_frame_size” = 256;

}: (

768799145985

)

I attached the complete console log excerpt, again this is typical of what happens upon each dropout.

If someone has also encountered this issue, and can share a workaround, or some other things to try I’d greatly appreciate it.  Thank you!