[SOLVED] Question on external DAC for PC - how does mine work?

[Minaz]

I have a "FiiO BTR5-2021 Receiver" external DAC which I use to power a set of headphones, and never really thought much about it. I have a soundcard in my PC which is integrated into an el-cheapo motherboard, but for whatever reason, even turned up fully, the headphones don't sound loud enough when plugged into the motherboard out, so I bought the BTR5 and plugged my headphones into that and since it worked, never thought about it again. Until now.

Browsing the web, I read that DACs can't produce sound without an amp. Wait what? That's certainly news to me because I have been listening to sound on my DAC the whole time. Is there secretly an amp in my DAC? And if so, then is my BTR5 unit actaully a DAC+AMP, and in that case, can it work independently of my on-board soundcard?

One of the reasons I am asking this is because I also read that when you plug a USB line out to say a pair of headphones (i.e. using USB instead of TRS/3.5mm), it outputs a separate digital signal from the motherboard soundcard. Since the BTR5 connects to the PC via USB, then if this is true, that would mean that theoretically, the DAC (+AMP?) could play music without there even needing to be a sound card right?

 

[hotaru.hino]

The on-board audio for the purposes of simplifying things is a DAC + Amplifier as far as the audio system is concerned. It's just that it's on board the motherboard. An external DAC + Amp is the same thing, just external and the data is fed via USB instead of whatever the internal interface is for the on-board audio.

With regards to analog sound signals, there are various types of "levels" that equipment can produce, depending on if it's an input (such as a signal coming from microphone or instrument pickup) or output (such as to headphones or speakers). What DACs output is something called "line level", which is basically in the middle. So it's stronger than an input level, but weaker (much so actually) than an output level. But it's meant to be a "reference" level of sorts so that you have a base level to work with. This is why you need an amp, so it brings the line level signal up to an output level signal.

See

View: https://www.youtube.com/watch?v=4rLwqQE3DJA