This one does: https://m.aliexpress.com/item/4001219988981.html

I didn't mean an AC charger, but a PD trigger that I can program to request any voltage I want. Currently only fixed voltages (5V/12V/20V) are available.

I think that's because PD spec is only those voltages (5,9,15 and 20 volts). You'll have to use a regulator or buck converter to get other voltages.

PPS extension allows for arbitrary voltages

Interesting, those PartyBox 100's have very good reviews and I've been considering getting one. How much play time do you get with that power bank?

With the power bank plus the internal battery, it plays for at least 10 hours on full volume, probably 12.

Also the sound is better with the external power bank, as the DSP limits volume and bass response when running on internal power. The PB100 is good value for the money, but don’t expect hifi quality. Its currently the best off-the-shelf solution for something you can still stuff in a backpack, unless you spend the big bucks and go with a Soundboks.

They really half-assed it tho:

- the LED lights are erratic and don't look that great

- the BT range is crap

- no built-in connector to connect external DC power like in the PB300

- internal battery life is not great, just 2400mAh, also not swappable

- no second set of tweeters like in the PB300

- takes a long time to boot (~20secs)

- no app to adjust the DSP or disable the startup sound