The phones out of the Fractal Axe Fx II sounds awesome. Detailed, lot's of highs. There is a significant loss of detail and high end when I am monitoring with headphones through an Apogee Quartet or Duet. I have tried every output option on the Axe II. They all have this problem. 1. Is this a Axe II problem? (I don't think it is as the Mackie HR 824s sound fine to me). 2. Is it an Apogee headphone amp problem? DAC problem? The Axe II through the Axe II phones is 3D, rich stereo, great detail and as I said great highs. Through the Apogee using Logic Pro X, there is definitely a loss of tone quality. It's muddier, detail is lost, etc. This is NOT a volume difference fooling my ears between the Axe Fx and the Apogee products. I thought both the Duet and Quartet were supposedly world class converters. So I am very confused and have spent two hours trying every possible configuration to figure this out. Suggestions? Does anyone else notice this? What would cause this? I am using short Mogami XLR cables from the Axe II to the the Quartet. I should be experiencing any noticeable change in tone.