I think there will not be double amping but instead giving an enhanced signals (pre-amp) from the dac -->dac internal amp (pre-amp) --> aegoM amp. It could be better or I might be wrong. Btw I was trying them before on the ibasso boa D2 which couldn't bypass the internal amp section, but it sounded nice too. Not sure it would be better if bypassing the internal amp. While the bypass in ibasso d2+ is in the case that u hav a separate amp for your headphone, then doubleamp is not desired, it could do no harm or maybe better for speaker amp.

I might have a Ibasso D2, sitting idling for quite some time already. If you are interested to buy, we can discuss about it through PM.

Sorry i didn't make it clear. I'm having a ibasso boa d2 which doesn't have the function to bypass, while d2+ can do that. But the d2 can sing just fine, but I never had a chance on the d2+. My point is it is okay to plug it in in the headline out and also the line out. Perhaps khaiyuen can tell us about the difference, which way is better?

Why don't just take DACport non-LX which include the amplifier in it?
It is a Class A amp which is quite a good performer.