———-[Mobile IO Conversion]———–
The MIO series uses Asahi Kasei (AKM) converter chips.
The AKM 5383 is a 108 kHz 24-bit ADC, used in both the ULN2 and 2882
The AKM 4393 is a 96 kHz 24-bit sigma-delta DAC, used in both th2 ULN2 and 2882
The AKM 5394 is a Multi-Bit 192kHz 24-bit sigma-delta ADC used in the ULN8
The AKM 4395 is a Multi-Bit 192 kHz 24-bit-sigma-delta DAC used in the ULN8
These are both stereo chips, so the ULN-2 has one for input and two for output, while the 2882 has four of each of them for the main analog I/O plus an additional DAC for the cans. The ULN8 has 8 of each, plus a DAC for the cans.
depending upon the sample rate, these AKM converters run at 128x oversampling – which happens to be the same rate as SACD. The DACs also have an 8x digital filter inside.
SRC in the 2882 and ULN-2 use a Cirrus Logic CS8420 Digital Audio Sample Rate Converter which runs at 108 kHz and 24-bit for real-time SRC.
The ULN8 uses a Cirruc logic CS8406-CZZ for AES input/output at 192kHz
There is a 24.57 MHz crystal on the Master Board, which matches the AK4393 clock requirement of 24.576 MHz for 48 kHz @ 512x oversampling and 96 kHz at 256x oversampling.