At time of writing, the ideal feature shopping list for a new USB DAC or USB-S/PDIF converter might look something like this:
- Asynchronous USB transfer
- TWO independent clocks (one for the 44.1/88.2/176.4 sample rate family, one for the 48/96/192 sample rate family)
- Galvanically isolated USB
- Integer mode capable
Integer mode – it’s the next hot topic of digital audio. In essence, it’s a computer transport’s ability to strike up a DIRECT conversation with the (the device driver of the) DAC or USB converter WITHOUT using the uppermost layers of the operating system (kernel) as a go-between.
You’ll need a software player that supports integer mode – currently only Audirvana and Pure Music if you’re on a Mac – and a hardware device that also supports it. Check out this handy list of devices over at Computer Audiophile; notice that M2Tech’s devices are all AWOL?
Normally the term “white paper” would be enough to put a glass eye to sleep, but here’s an integer mode white paper that’s surprisingly layman friendly. It’s written by Damien Plisson who is the developer of Audirvana and it features some comprehensive background information on the nature of jitter (without sounding too dull). Go on – it’s only 3 pages long.
There’s also some great background information to be had – as always – over at The Well Tempered Computer.