HagUSB vs Other USB Interfaces/Devices

There is no such thing as a DAC that "supports" ASIO. The DAC simply takes the digital stream that it is fed and converts it to analog. It is the player software that either does or does not support ASIO. Apple iTunes does not, foobar has plugins that do, Windows media player does not, etc. As long as the data comes at a standard rate like 44.1 and in a form it can decode the DAC doesn't care whether it gets adulaterated digital from a player that passes its data through kmixer, or unprocessed data like you would get from a mac or a player that bypasses kmixer.

Herman....that is incorrect. There are DACs that support ASIO - but they must have USB input. It gets the signal via USB from the player (which as you state, must support ASIO output) and it must be able to utilize that data before sending it to the D/A process.

Many USB interfaces are like this: they have USB input and a built-in DAC, although many people simply use those to get USB out using ASIO, have a digital signal generated, and have that digital signal sent to an external DAC (such as one which does not have USB input). A good example of this is the EMU 0404 USB or Edirol UA-1EX. I used the latter prior to getting the external DAC - fed it USB, it supports ASIO, and I used its DAC capabilities too thus outputing an analog signal to my amp.

X

You are mistaken.

Asio is a software protocol to handle the digital data BEFORE it is sent out the USB port to the DAC. It is capable of doing various things but the one we are interested in is its ability to bypass Windows kmixer. The kmixer is an embedded software routine in windows that re-samples the data (in other words it corrupts it) prior to sending it to the USB port. Any program that outputs audio via the USB port will suffer this corruption unless they use an asio driver.

It is completely a function of software and completely independent of the hardware. Any USB DAC can handle the data from windows whether or not it has been processed by kmixer or bypassed by ASIO.

It is the USB device driver that supports ASIO.

Steve, every USB DAC I've tried or read about was detected automaticaly by Windows or my mac and you could use whatever program you prefered (iTunes, foobar, etc) to play your music.

Do some of them require specific drivers that are not part of Windows?