Here is an overview of some of the things responsible for the overall sound a DAC design. There are actually more things involved than I will list mind you, even though this list may seem longish.
- Input receiver choice (the circuit the connects the incoming digital signal jacks and transfers the digital data to the DAC chipset itself)
- Power supply design for the DAC, input receiver power supply quality and output gain sections.
- Any filtering that may be incorporated on the incoming AC and/or digital data input and/or DAC chipset output (which can be within the DAC chipset itself) and/or the output stage itself. Read; FOUR DIFFERENT CIRCUIT AREAS within the DAC which could have filtering implemented of various design and quality choices on those differing circuits.
- Regulation choice for the above circuit sections.
- Jitter reduction methodology, if any.
- DAC chipset choice and implementation.
- Board layout, EMI, RF and noise considerations of the various circuits involved.
- Output section choice (op amps or discrete?)
- Bias of the output devices, if they need biasing.
- Power supply caps, quality, amount, power supply circuit implementation.
- Current to Volt conversion circuit topology for DAC chipsets that require it prior to the gain stage.
- Various supporting components, resistors, clocking, supporting component quality for input, power supply(s), DAC chipset, regulation(s), output devices and quality of caps used on capacitor coupled output stages- read; discrete output which is a better step-up sonically above utilizing Op Amp outputs.
As you can now see from this list, the variables within a given DAC design are many. Hence, the differences between two different DACs are so much more than just "the DAC chipset" choice or "the jitter reduction"; which are typically the only core technical things discussed as "the crucial components" of the DAC design. If creating a heroic sounding DAC was only as simple as the DAC chipset and the jitter reduction ;-)
Cheers,
Eric Hider - dB Audio Labs