What is the deal with these modes? Today, I played around with my Onkyo TX-8555 stereo receiver's Pure Audio and Direct modes while playing some CDs, and honestly, I couldn't hear any difference between them and normal Stereo, where the tone controls are active... I understand that these modes bypass the bass and treble controls typically, and the Pure Audio even shuts off the receiver's display and video circuitry for supposed "cleaner" audio transfer and delivery, but honestly, I couldn't hear much, if any, difference between Stereo (where I leave my bass and treble at the midway default anyway) and Pure/Direct. With Pure and then Direct, the bass was still punchy and active, and there wasn't really any "cleaning up" of the signal that I could detect -- are these modes supposed to be readily audible in terms of sound differences or are they basically just bypassing the tone controls? I'm thinking I'll just stick with the normal Stereo mode output and leave the bass and treble at midway... Any thoughts?