GaN switching USB chargers are pretty commonplace now, and can be found for 15 dollars or less. Are they intrinsically better for audio due to their higher switching frequency than silicon based switching USB chargers? Are they better than linear USB chargers?
this guy does a deep dive on phone chargers, very interesting, may be of some use....
A dozen USB chargers in the lab: Apple is very good, but not quite the best
A dozen USB chargers in the lab: Apple is very good, but not quite the best
https://www.eetimes.com/gan-enabling-a-revolution-in-charger-design/
Suggests 70kHz for Si in 2008 versus 90kHz GaN 2020. Hardly a "WOW!" difference. Does suggest >5X power per volume.
What Is a GaN Charger, and Why Will You Want One?
Recent but light-weight article
"The promise of GaN in light of future requirements for power electronics"
More tech/geek sales pitch
Suggests 70kHz for Si in 2008 versus 90kHz GaN 2020. Hardly a "WOW!" difference. Does suggest >5X power per volume.
What Is a GaN Charger, and Why Will You Want One?
Recent but light-weight article
"The promise of GaN in light of future requirements for power electronics"
More tech/geek sales pitch