Originally Posted by rovopio
hi guys.. im thinking about buying some small budget tube dac (aune t1). when i ask from the local seller, they said they dont hv aune t1, but they hv aune t1 mark 2. the difference is that now it uses nonsynchronous usb technology. i asked on the aune t1 thread but everybody seems to have the previous version. i tried googling but i couldnt find what it means as of yet.
is nonsynchronous usb technology a pc term...? can anybody teach me what it means...?
The correct terms are synchronous and asynchronous (which most call async).
The second source should be the easiest to understand, and then the first one will be easier to understand once you get the basic idea.
Most basic explanation:
synchronous: basically the classic game of pong or the sport of tennis, ping pong, etc. You send the signal and don't do anything until you get one back. ex. texting between you and another person. You don't respond until you get a reply.
asynchronous: sends a signal and then move onto something else while waiting for the response, but then switches back to that original task after receiving the responding signal. ex. Between texts you go and do your homework. Once you get that text back, you stop doing your hw and send another text. Then you resume to doing hw.
What the use is in audio: http://hifi-advice.com/USB-synchronous-asynchronous-info.html
Not sure if I can trust that source but it seems like something you can deduce from the basic definitions of async and sync I/O.
With sync I/O, your computer likes to send signals based off of its own timings and your USB controller in your DAC likes to send signals at its own clock. It's like people living in different time zones: you're okay to make phone calls to them at 9:00 PM EST while they, 12 hours ahead, like to make calls at 9:00 AM EST when you're still sleeping or have just gotten up.
With async I/O, the two take that spare time in between to adjust clock rates so that they match up. It's essentially like that friend in another time zone moving to your time zone or vice versa (or you meet up somewhere at the same place).
Ideally async makes the data transfer as seamless as possible so that every window of opportunity is used to send data instead of being confused over the different times the two USB controllers expect send/receive commands based on their own internal/system clocks.
Edited by HybridCore - 6/3/14 at 3:21pm