My ADA interface is an E-MU 0404 PCI card: http://www.sweetwater.com/store/detail/0404/ With its outputs leading to my Presonus HP4 headphone amp: http://www.sweetwater.com/store/detail/HP4 Which then go to my studio monitor and headphone mixes. My question is, is the HP4 negatively affecting my mix coming through the monitors cuz its a cheapo headphone amp? I bought it so I could have multi-headphones out (w/volume controls) and a monitor controller. Did I make a bad choice? Is the mix from my monitors now "whack"? THANKS!