Hegel H590 or H400

the H590 has more voltage headroom naturally for more wattage output but bth have ample swing for your speaker to not be a factor.

Streaming protocols is where the H400 is better:

the H590 does Apple AirPlay, Spotify Connect, Roon Ready, UPnP

and

the H400 does Spotify Connect, Roon Ready, Tidal Connect, Google Cast, AirPlay, airable Internet Radio and Podcast, UPnP

Sample rate headroom is better on the H590

Damping factor is about the same so sonically they should basically let the speakers shine without any driver sag. 

So basically which compromise you're willing to take. @krelldog 

I never used the internal DACs on my current Hegel H590 (5 year ownership), or the H390, which I owned prior to the H590.  The H390 was excellent and I would probably still own it if I hadn't switched to larger, more inefficient, full-range speakers.  Although the H390 could've nicely driven my new larger speakers to a degree, I still preferred the more detailed, neutral, dynamic, more powerful, etc. sound of the H590 over the H390, so I kept the H590.  Never heard the H400.  But I did get a chance to hear the H600, which sounded very similar to my H590.  For my speakers, I would need the extra headroom that the H590 provides over the H400.  You don't need the extra power, so it would come down to which internal DAC sounded best in your system.  For the same money, I'd audition both before making a decision (then again, I'd probably still run with the H590).  The H590 in an absolutely incredible piece of gear.  Happy listening        

I A/B ed the 590 vs. the 600.  The 600 was a noticeable step up.  I suspect the new DAC has a lot to do with the difference.  Maybe take a good look at the 400 if you can demo one.  

Great feedback, I appreciate the input.

IIRC the many felt the H590 was not worth the increase of price to the H390 for the slight sonic uptick. Both DACs performed similarly very good.

The subsequent release of the H600 had a notably sonically better DAC so I assume the following H400 has the same DAC sonic upgrade.  If so, since the OP plans to use the internal DAC, my nod goes to the H400.