Toothless_SnakeI have both. As a stack it looks great and is versatile in terms of input and output options.
If I had to choose one I'd get the X7S and a cheap dac like a OL DAC or Topping D10 or D30.
The X7S is a superior Amp. I use it with my 6xx and 4xx and it's excellent. Everything sounds more full and low end hits harder.
That said, the X1S is a great DAC and is more than sufficient to drive most headphones.
MikefromEarthThe X7S is slowly changing my mind about liking the HD 600s more than the HD 650s. I didn't think that was possible. So does he 'need' an X7S to get loud? No. But it sure sounds great. Especially balanced. Single ended is a sound quality upgrade from my Xonar STX and my O2/ODAC Rev B. Balanced makes it even better.
mindhead1Quick question sir if you don't mjnd. Just curious, lets say I use USB to X1s, then RCA Output from the X1S to another Amp RCA input. Does it means the X1S function purely as a dac? I'm quite confuse with how DAC/Amp works. That being said if I do own a Dac/Amp and wanting just to use it's dac but another different amp.
DeathbedYes. When you use the RCA out from the X1S it's in DAC only mode and can feed another Amp or powered speakers.
Unlike some DAC/Amps the RCA out is not disabled on the X1S when headphones are plugged in. I have not noticed any issues with sound quality because of this.