Yulong DA8 is actually more on DAC. The build in amp can't really drive headphone like HD600 or K701. Even a RM500+ Cayin C5 portable amp is better than it. So I don't suggest using it as a DAC cum amp.
But it is indeed a very good DAC. It has balance line out for DAC. To get the whole potential out of it, you should pair it with a decent desktop amp.
If you want a full balance system, then can get a full balance amp. But that might be over your budget.
One of the best combinations I have for HD600 is Yulong DA8 + Lafigaro 339 with upgraded tubes. (total budget around RM7K, excluding upgraded power cord, usb cable, rca cable and receptacles). Lafigaro amp is single ended, but with widest sound stage that I ever heard even compare to higher range amp. It has the typical tube amp sound, warm and rich with good ambience, with good dynamic as well. HD600 sounds very open, detailed, and musical, which makes lafigaro stands out from the rest for HD600.
You can also consider getting their brothers, D200 + Lafigaro 332S. D200 also has balance output and support DSD.
Yulong D200 is more direct sounding and have strong punch at bass compare to DA8. DA8 has wider sound stage, smoother and more musical. Both are clean, neutral, refined, airy.
Other DAC at around the same range, you can also consider Aune S16 with use the latest DAC chip AK4495S from AKM and Matrix mini i pro.
S16 has a stronger build in amp among the rest and can last for a while as a DAC cum amp. But still can't compare to a pure amp.
Matrix mini i pro wise, has very analogue sound, smooth and more on the mids.
If you prefer a DAC cum amp with balance system, I suggest you to consider Audio-GD NFB28. All the models of Audio-GD with ES9018 DAC chip supports DSD, so you can check them out. Audio-GD always has very strong output power for headphones.
It's thick with slightly dark background, sound stage is moderately wide but with good depth, accurate with good punch. What I like Audio-GDs the most is that, music becomes so lively, every single track is like listening to a live concert which makes it so special from the others. I was confused and getting headache when trying to mix and match for my Master 9. My doubt is all resolved until I manage to audition Master 7 + Master 9 combo. So REAL!
It's not a perfect system that emphasize on every technical parts of the sound. But it's definitely a system with strong character, special, charming and so musical.
That doesn't mean it doesn't have good details or separation. It just doesn't push them to your face.
And Congrats on your new business store.
Now I have few lists of Desktop DAC from you. Right now I dont have plan for AMP part yet, thinking of settling DAC first.
Quite surprise the AMP part of Yulong DA8 is weaker than portable amp. That means if I want to buy DA8, I need to get an AMP
Aune product gives me a good impression (as I bought X1 pro dac from you) but I want to try different brand.