Forgot to mention another pretty much useful, just discovered, feature. If you use direct mode surely enough analogue outputs will be fixed and it's desirable mode when external pre-amps are in place, so that Micro pre-amp is bypassed (and volume buffer in general). However, headphone pre-amp section is still active and reactive to volume control, filters and effects and analogue outputs are not muted when the actual headphone is connected. So, in essence, one can use in parallel external amps and excellent Micro headphone amp with independent volume control. Very useful indeed!