This is my first tube amp. I have an eye towards good return on investment and the price / value was tempting. My system uses a macbook Pro hooked to a CalDigit TB3+ and a FocusRite Solo hooked over USB to the CalDigit. I had the line out of the FocusRite feed the DarkVoice (cable 1/4 to RCA).
At first, I heard crackles and hiss as I moved the mouse on the computer. I was *shocked*. It caught me by surprise. The sound seemed good, but the hiss was too distracting. I checked online and found many post discussing ground loops and the need to add a device to isolate the "PC" (my mac) from the audio. I couldn't believe that a machine as good as a macbookPro would have an issue. So I tested various components to try and understand. At some point I thought: "Wait a second, the macbook is powered from the CalDigit over a TB cable and the data to the CalDigit goes over the same cable. What if.... I powered the macbook Pro from its actual power supply ?
I tried and _all_ noises disappeared instantly. Powering the macbook from it's power supply and keeping TB to feed the CalDigit was all it took.
Now the DarkVoice produces an amazing sound and I couldn't be happier. I might tube roll later on, but this is already really really much better than the analog output from the focusrite.
Highly recommended, awesome value for the price.