When we think of streaming audio we probably gloss over all that’s involved – and there’s a lot involved. You’d think streaming audio should be as easy as selecting what you want to hear, pressing a button and getting it to play. In some cases it’s that easy, such as using Apple’s Airplay option, but with every easy solution comes a host of restrictions and limitations you have to deal with.
Today I thought we might explore the most basic streaming audio option: streaming to a sound card inside a computer and playing the audio to your DAC. Later we’ll take a look at the same thing only connecting over your network. The first thing we need to understand is how your computer communicates with your DAC.
The vast majority of streaming audio use in high-end audio is when you’re tethered to your computer through USB or TOSLINK. In this popular setup, the DAC is the player and is connected to the computer either via USB or through a digital output if one is included with the computer. Like a dog and its owner out for a walk, the pair are forever tied together on a short leash unable to operate independently of each other.
Since the USB connection is the most popular “short leash” solution (USB Is limited to something less than 3 meters) I will keep the discussion centered on USB.
The first thing we should understand is the need for a driver to make this work. So, what’s a driver? A driver is a small piece of software your computer uses to communicate with another piece of equipment. Because your computer is asked to connect and control or be controlled by attached equipment like printers, speakers, video monitors, your mouse, your keyboard, etc. a method had to be devised that helps the computer understand what it is being asked to do with connected peripheral equipment. Every attached piece of equipment you use has a driver the computer uses to connect up to it – and your DAC is no different in that respect than your printer or keyboard – you just have to make sure the correct driver is installed.
From a user’s perspective it may not seem like you need a driver for something to work – like when you plug in a printer, USB memory stick or keyboard and it just works. But this is only an illusion – as everything you add needs a driver. So when you plug in your printer and it just works, what actually happens is the driver for this device was already installed on your computer. Macs make it really easy for people to connect gear – not because they are better machines – but because Apple constantly adds new drivers into the computer’s memory so it just seems effortless when you attach a new printer – and from the user’s perspective it is seamless and easy, but it takes a lot of work on Apple’s part to make that happen. In other words, there’s no magic going on at all.
Ever notice that most modern DACS are limited to 24 bit 96kHz on their USB inputs while the DAC itself is capable of higher sample rates? The reason for this is that both Mac and Windows computers have preloaded drivers that support this level of USB audio and USB chip makers provide plenty of easy-to-implement solutions based on these drivers, making it super easy for users to simply plug in the device and DAC manufacturers to implement it on their DACS. Plug-and-play still requires drivers to be installed, but in this case the drivers were loaded without you, the user doing anything.
When you connect up our new PS Audio Mark II DAC that offers 192kHz 24 bit USB performance, it “automatically” connects on a Mac computer yet Windows computers require you to download a driver and install it to make it work. Again, Macs simply have the needed driver preloaded and Windows doesn’t – but it won’t be too long before they will.
The whole point is not to make a comment between Mac and Windows but to help you understand what a driver is and what it does.
So, in conclusion, whenever you attach and connect anything to your computer, from a mouse to a DAC, the proper interface or driver must be installed to make it work. The driver merely tells the computer what your attached device can and will do and how to communicate with it.
Tomorrow we will discuss getting music to the driver and what it means.