I bought an ibasso d2 headphone amp / dac to connect my new Sentheisser headphones to in order to get higher volume levels and better quality on my computer. I had a realtek onboard soundcard previously. I'm new to amps so I plugged in the amp to my usb and it installed the drivers automatically, I disabled the realtek soundcard. Now here's my problem: I only get 1 volume level no matter what. The setting in my computer is maxxed and I get the same volume no matter what I set it to. Even when my amp volume switch is turned off or it is maxxed I get basically a mid level sound volume that can't be adjusted on the camp or through the computer settings. Am I doing something wrong? Thanks for the help!

You aren't plugging in your headphones to the Aux output, are you?