I don't really like the Shangling UP4 unfortunately.
The instrument seperation, layering and resolution across the frequency range is too lacking for me, on complex arrangements it loses control.
I tried every bluetooth codec, latency and combination there is in my developer settings.
I think my smartphone Huawei P20 Pro doesn't go well with Bluetooth.
The connection can not hold up when using high LDAC or hwa, so I can not judge the music quality there.
I found no differences between aptx, aptxhd, aac or sbc.
The codec I liked the most was SBC, because it was the most stable.
My bluetooth buds Samsung Gear IconX sometimes have random reconnections.
The Huawei P20 pro is not recommended.
I unfortunately do not have access on other smartphones.
I'm sending this back and will try to get the Qudelix 5k in the future, when I have upgraded my smartphone.
Don't think UP4 will be enough unbalanced out for HD650.
I already have sent my HD650 back, so I could not test it.
But judging with the Focal Clear, I don't think the Shanling UP4 will be enough. Maybe very very close, I would definitely go for a stronger option.