In theory they could use an ADC to convert the analog input to digital then run through the same DAC as bluetooth goes
If the original device's DAC has produced a shitty analog signal, the best ADC in the world will only be able to turn it into a shitty digital signal.
The strength of a chain is that of its weakest link.
Re:AirPods don't “just work”
by KptMarchewa on Thursday January 27, 2022 @06:49AM
(#30099338)
I have new MBP 14', and even external fiio E10k headphone amp. They work great with my Sennheisers HD 650, but suck with WH-1000mx3 compared to internal AMP.
I have an older pair of JBL E55, which are about 50% cheaper than yours, and on a modern phone they sound slightly better on wire than on wireless, presumably because their internal DAC is mediocre.