Basically the title. I never had and amp in my life, Fidelio X3 are my first “good” phones. I wanted to know if I should buy that DAC, or other or none. Also, what am I expected to happen? Just louder music? Or some corrections (I say it and it sounds stupid because in no way it can understand what the headphones are like)? It is a portable DAC means that if using in a phone, it drains the battery a bit faster right? Same for a laptop I suppose, but if plugged in it has no impact. Also, how does it deliver the power? Is there a way to control it? Or automatic? I read about the rule of eigh, but it doesn’t show anything to regulate.
Read a good review from a mag on it. It will explain it in detail. Seems like it won’t be enough for your needs. Yeah an amp amplifies power, volume, not to be confused with gain which distorts at higher volume levels. The Dac allows the sound to be processed to mono so you can hear it, better in some cases I assume. Those Fidelios are power hungry so definitely bigger amp. I still use an old OB Creek amp I got in like 2000.