I’ve had this problem before and it was because my USB port was being a bit weird, although later I discovered that everything was being weird because I managed to only “half plug-in” the HDMI cable. That caused everything to freak out.
Anyway to see if your Zen DAC is running in the right mode you can try this in the command line:
cat /proc/asound/card5/stream0
Mine is “card5”. Yours could be “card0” or “card2” etc. Just look to see which ones you have. The first line should tell you whether it’s running in “Full Speed” or “High-Speed”. When mine was showing “Full Speed” all I had was up to 96kHz like you’re experiencing. Plugging out and in again fixed it for me. If it doesn’t work for you then I would try a new cable/port.
This is what the stream output should look like:
iFi (by AMR) iFi (by AMR) HD USB Audio at usb-0000:01:00.0-1.3, high speed : USB Audio
Playback:
Status: Stop
Interface 1
Altset 1
Format: S32_LE
Channels: 2
Endpoint: 1 OUT (ASYNC)
Rates: 44100, 48000, 88200, 96000, 176400, 192000, 352800, 384000
Data packet interval: 125 us
Bits: 32
Channel map: FL FR
Interface 1
Altset 2
Format: S24_3LE
Channels: 2
Endpoint: 1 OUT (ASYNC)
Rates: 44100, 48000, 88200, 96000, 176400, 192000, 352800, 384000
Data packet interval: 125 us
Bits: 24
Channel map: FL FR
Interface 1
Altset 3
Format: S16_LE
Channels: 2
Endpoint: 1 OUT (ASYNC)
Rates: 44100, 48000, 88200, 96000, 176400, 192000, 352800, 384000
Data packet interval: 125 us
Bits: 16
Channel map: FL FR
Interface 1
Altset 4
Format: SPECIAL DSD_U32_BE
Channels: 2
Endpoint: 1 OUT (ASYNC)
Rates: 44100, 48000, 88200, 96000, 176400, 192000, 352800, 384000
Data packet interval: 125 us
Bits: 32
DSD raw: DOP=0, bitrev=0
Channel map: FL FR