FWIW I’ve owned both of these and like them both a lot. I would say Luxman sounds more natural tonally with a clean and clear presentation that is also sweet, liquid, and a touch warm. Hegel also has a sweet, but a touch drier and meatier sound, a bit darker, more clearly defined soundstage, better control and bass authority. Maybe a little too much control, meaning tone seems to be subtly lacking some harmonic complexity and natural decay compared to Luxman. Luxman can sound a bit thin at times.
Good description eugene81. Although I do not have experience with Hegel amps, your description pretty much mirrors mine with regards to the Luxman in my case L-590AXII vs a dozen other assortment of amps both integrated and pre/power. The Luxman excels in reproducing the nuance and fine detail in the music. It’s a more delicate sounding amp in comparison to other alternatives which may sound bolder, more dynamic or with more impactful bass etc. But in turn some of the nuance and fine detail are masked or not reproduced as effectively as the Luxman.
The speakers that will be matched to the amp will play a huge role too as the speaker-amp interface is of utmost importance. Different speakers, different result. Nevertheless, generally in my book :
LUXMAN (L-590AXII) - clean, refined, delicate, detailed, sweet and slightly warm at the top
OTHER SELECTED AMPS - slightly hazy, not as clean, refined and detailed with a less nuanced delivery although music may sound bolder or more dynamic with punchier bass etc.