With headphones too, and hopefully without any prejudice...
For my set up, please refer to posts #1216 and #1243. Just to add that source and amps are fully balanced. I can only report listening impressions. In particular, I checked for differences in the soundstage orientation which are almost "visible" if I may use this term. Also, the results were similar with amps-speakers and headphones so I think I have a clear picture of how DCG3 sounds in different configurations. "Clear picture" is a big word though as differences were not spectacular but playing well known tracks I could "see" them.
Only way to get a proper headphone output was to use my -allready former - tube DAC output stage and connect DCG3 after it. It worked fine and I managed to listen through my AKG K180 600 ohms cans! They have got balanced wiring plus an adaptor for SE stereo jack. Like others report for their builts resolution is great. Unfortunately, headphones do not work with me. I cannot get the 3D illusion and this leads to fatigue. This said, I loved this track:
YouTube
But one thing is sure there is difference between SE and balanced mode! In balanced the instruments are more defined and separated. Also, the sound is louder! I guess the theoritically predicted increase of 6db.
I had a better chance to confirm this by listening through amps-speakers.
Soundstage width remains the same in SE and balanced mode since in both cases the psu is separated for the two channels. But in SE mode the outer limits fade out leaving the center and especially voices more pronounced. In balanced mode all instruments get more authority no matter where they are placed in space. I did a rather unusuall test. I compared SE mode with three different configurations: one phase fed with positive and the other with negative but SE output only from positive phase (A) vs one phase fed with positive signal and the other idle and floated (B) vs both phases fed with positive signal and SE out only from one (C). From A to C there was a gradual loss of details like strings vibrato for example. My idiosyncratic system is not a reference for what others may expect from their systems but I report what I was able to listen. Lately, I thought to explore the theoritical advantage of the differential amplifiers to present a constant load to the psu so there would be less interaction between them and I think I witness to this with DCG3 too. I hope it's not the result of a biased opinion...
Tested with R7 as is it doesn't work. I guess R7 should be lifted and connected but I didn't test that. I liked mine with balanced input even if SE output was used. Transformers or chips? If silicon has to be coupled via capacitors I would prefer transformers. Any of these should be done at the input of DCG3 at least IMHO.
, still I get goosebumps with the idea to dissasemple my build again. Of course, never say never...