DAC : DIGITAL TO ANALOGUE CONVERSION
Signal reception :
An integrated circuit called AK4118 is used as a digital audio receiver. It can handle 8 inputs supporting up to 192 kHz in 24-bit format. It then transforms the selected input into a 32-bit I2S format, while maintaining the same sampling frequency as the input signal.
Oversampling :
An integrated circuit called AK4137 is used as a sampling frequency converter. After asking the AK4118 what sampling frequency is present at the input, the signal can be oversampled. At the same time, all the signals are kept synchronised.
The signal is now sampled at 768 kHz. This increases the finesse and resolution of the musical signal by a factor of more than 64.000, and the number of samples converted is multiplied by 16. This allows the signal to be filtered at higher frequencies, removing the residue of digital conversion from the audible band.
Conversion :
The digital converter is a ROHM integrated circuit, converting at 768 kHz and 32 bits.
Note that all the digital signals are synchronised with each other. In other words, the digital clocks (square electrical signals) go up and down at exactly the same time. This allows the signal to be converted at exactly the right moment, so that not a single crumb of information is lost from the original signal.