You could have renounced the «even», as this feature is even a great advantage: Just one amplification stage straight from the DAC to the combined line/headphone output – a signal path as direct as possible for a minimal loss of transparency. If you look at the measuring values, you'd have to concede that it's almost unrivaled when it comes to harmonic distortion and output impedance. You just can make it (metrologically) worse by adding an external amp. Note the «adding»! From a technical perspective fighting harshness by means of an additional amplification stage is a questionable strategy. It works because most amps tend to smooth the edges of a signal, and the reduced transparency makes for a certain forgivingness. The downside is a loss of immediacy, transparency and realism. I still haven't heard the Mysphere, but in any event I would try to equalize whatever you perceive as harshness instead of masking it with harmonic distortion and reduced accuracy. Granted, the Hugo₂ isn't entirely neutral (BTW, no electronics component is), something I can reproduce with the EQ curves I have to apply relative to e.g. the DAVE: The upper treble is slightly accentuated (resulting in an attenuation by up to 0.6 dB above 10 kHz in my EQ presets).