DAC CS4382A (Outputs)
CS4382A: This Digital to Analog Converter (DAC) chip features advanced Multi-bit architecture and provides high quality output for up to 24/192 KHz. This converter has a dynamic range of 114dB and a THD+Noise value of -100dB. The chip also offers a low sensitivity to jitter and on chip selectable filters.

ADC -WM8775SEDS and WM8782S (Inputs)
This is a 24 bit Sigma Delta ADC with built in four channel mixer and rated for 102dB Signal to Noise Ratio with -90dB of Total Harmonic Distortion (THD). This chip also has programmable level control (ALC) and can handle sampling frequencies from 32 KHz to 96 KHz.  This Wolfson Analog to Digital Converter (ADC) chip is responsible for digitizing signals from the Rear Microphone input, the Line level input and if an Extension Bay is connected you would also have an Auxiliary input connector this chip would be responsible for.

WM8782S
This 24 bit multi-bit stereo ADC is dedicated solely to the handling input from the front panel Microphone connector. The converter and features over sampling to 128X and can handle frequencies from 32 KHz up to 192 KHz.  This Wolfson Analog to Digital Converter (ADC) chip is responsible for the front panel microphone input. Auzentech used two ADC chips to make recording from two independent sources easier.

Capacitors (Filters)

Nichon MUSE ES - Auzentech opted for Nichon Muse ES grade audio capacitors (green Cylinders below) for the output coupling capacitors.

Theses filters have been designed specifically with audio signal use in mind.  They are much higher grade then the generic caps usually found on PC audio hardware. 

The red caps up near the opamps are metalized film capacitors forming the LPF for the DAC front output stereo pair.  Another circuit point where the designers opted for something a bit better. Nice!