Thank you for the suggestion, it is an interesting one. But I would prefer to keep everything in a single device (paired with Sabaj A20a amp) and sell the D30. I mainly use USB input and occasional Bluetooth, so easy or automatic input switching would be great.Topping BC3 is a Bluetooth receiver with LDAC that also has optical out. So you could connect it to the optical input on your D30, assuming you're not using that input already.
This is a review and detailed measurements of the Topping BC3 Bluetooth receiver and headphone amplifier. It was sent to me by the online seller, Yaoyaotiger HIFI Audio Store and costs US $69. This is a follow up to our previous tests of Bluetooth receivers and investigating performance of...www.audiosciencereview.com
Of course if you're also anxious to upgrade your headphone amp, then the DX3 Pro+ could be a good choice
I do not have nor do I plan to ever use headphones.