I haven't tried audio-gd's musical dac's and amp's, the closest I got are clearly colored modules for the compass and sparrow and the transistor-based output on the ref 3. But I'm just sharing my thoughts because people may actually want some coloration but are afraid of music sounding like syrup, but they might not have to be afraid of that happening because their diamond differential gear are described as only "slightly warm and soft".
Someone mentioned it recently, and I think it makes sense, maybe some of us who think of "musical" think of the highly colored moon hdam in the discontinued compass. The moon hdam is described as "Full of emotion" and the compass itself is described as in the middle of neutral and musical by Kingwa (if I remember correctly).
After much testing myself I very much agree with Majkel's descriptions of the sound signatures of the different audio-gd hdam's, so I'll quote what he says about the moon opamp here.
Quote:
OPA-Moon
The sweetest and the most romantic one. Slightly darker than the other two, a natural step-up from the AD825 pair as I know there are lots of their fans. This one has got big but defined soundstage, the listener becomes a part of the spectacle. You feel emerged in the music flow however the musical fluid is not completely spiced for me. I don't want things to be sweet or salty all the time, I need a tiny sip of sour or bitter flavor sometimes, making the dish more refined. In other words, the music does not have to be sentimental all the time, I'd like it to be intriguing and surprising sometimes.
Personally I considered compass+earth hdam as 75% neutral, deviating by giving a little bit gritty sound and a little more flare.
compass+moon hdam as 40% neutral, it always tries to carry you away with a a few different sentimental emotions.
and dac19/dac9 as 90-95% neutral, not 95-100% because of rolled-off upper highs. These frequencies are usually just agitating but on some occasions they may be part of the music.
RMAA says many audio-gd gear are not neutral
![Stick Out Tongue :p :p](data:image/gif;base64,R0lGODlhAQABAIAAAAAAAP///yH5BAEAAAAALAAAAAABAAEAAAIBRAA7)
, so I define neutral only as a psychological effect, allowing you to hear an objective interpretation of how a recording was mastered and allowing you to focus on each sound without being pulled into the music if you don't consciously choose to. I define musical as engaging you into the whole of the music, can allow you to grasp the meaning of a song better/quicker than with neutral gear, but making it harder to focus on the EXACT intent of individual instruments.
My guess is that diamond differential audio-gd gear is probably closer to earth hdam+compass than moon hdam+compass in degree of coloration, but from descriptions I read the coloration type is probably in the same vein as moon hdam, not earth hdam.