I downloaded your zip file. I was somewhat unclear about your instructions on how to use it, so I opened a terminal and ran the file as follows: ./alsacap
On completion, the terminal output was:
*** Scanning for playback devices ***
Card 0, ID `NVidia', name `HDA NVidia'
Device 3, ID `HDMI 0', name `HDMI 0', 1 subdevices (1 available)
2..8 channels, 32000..192000 sample rate range, sampling rates 32000, 44100, 48000, 88200, 96000, 176400, 192000 Hz
Sample formats: S16_LE, S32_LE
Subdevice 0, name `subdevice #0'
Device 7, ID `HDMI 1', name `HDMI 1', 1 subdevices (1 available)
2..8 channels, 32000..192000 sample rate range, sampling rates 32000, 44100, 48000, 88200, 96000, 176400, 192000 Hz
Sample formats: S16_LE, S32_LE
Subdevice 0, name `subdevice #0'
Device 8, ID `HDMI 2', name `HDMI 2', 1 subdevices (1 available)
2 channels, 32000..48000 sample rate range, sampling rates 32000, 44100, 48000 Hz
Sample formats: S16_LE
Subdevice 0, name `subdevice #0'
Device 9, ID `HDMI 3', name `HDMI 3', 1 subdevices (1 available)
2..8 channels, 32000..192000 sample rate range, sampling rates 32000, 44100, 48000, 88200, 96000, 176400, 192000 Hz
Sample formats: S16_LE, S32_LE
Subdevice 0, name `subdevice #0'
Card 1, ID `X2', name `X-SPDIF 2'
Device 0, ID `USB Audio', name `USB Audio', 1 subdevices (1 available)
2 channels, 44100..768000 sample rate range, sampling rates 44100, 48000, 88200, 96000, 176400, 192000, 352800, 384000, 705600, 768000 Hz
Sample formats: S32_LE, SPECIAL, DSD_U32_BE
Subdevice 0, name `subdevice #0'
Card 2, ID `converter', name `Schiit Jil A to D converter'
Card 3, ID `Interface', name `32bit 384kHz Dsd Interface'
Device 0, ID `USB Audio', name `USB Audio', 1 subdevices (1 available)
2 channels, 32000..384000 sample rate range, sampling rates 32000, 44100, 48000, 88200, 96000, 176400, 192000, 352800, 384000 Hz
Sample formats: S32_LE
Subdevice 0, name `subdevice #0'
Card 3, ID `Interface', name `32bit 384kHz Dsd Interface' is the Wyred4Sound DAC-2v2se.
I then ran MC25 with the DSD2x option and it worked fine showing DSD128 on my DAC.
Then I ran MC25 with the DSD4x option and got an error about 96k/24 bit and no output.
I also should note that when running the HQPlayer program as per the settings noted in my earlier posts on the matter, HQPlayer shows a DoP4x conversion as per the attached jpeg. As you can see HQPlayer is upsampling the 44.1k/16 bit FLAC file to a 6.144Mhz rate as opposed to MC25 which appears to use 11.xMhz, which, as you noted, is beyond the DAC-2v2se capabilities.