TIL the DS Phat outputs sound through the GBA SP-style charging port (with the SP headphone adapter). : r/nds
New 3.5mm Headphone Earphone Jack Adapter Cord Cable For Gameboy Advance Gba Sp - Buy 3.5mm Cable,Adapter Cord Cable For Gameboy,Adapter Cord Cable For Gameboy Product on Alibaba.com
GBA SP headphone adapter by Gamester. This one still allows access to the charging port. :) : r/Gameboy
GameBoy Advance - 1x Headphone Adapter for GBA SP [various colours and brands] | eBay
5pcs New Headphone Adapter Cord Cable For Gameboy Advance GBA SP Earphone Headset|cable for|cable for headphonescable for earphone - AliExpress
GBA SP headphone jack mod | Hackaday.io
GBA SP Gameboy Game boy Advance SP Earphone Adapter Black (allows you to use your standard earphone on GBA SP) : Amazon.co.uk: Electronics & Photo
2020: The Year The Game Boy Advance SP Finally Gets A Headphone Jack | by Matt Hawkins | Attract Mode | Medium
Headphone Earphone Adapter Cable for Nintendo GBA Game Boy Gameboy Advance SP UK | eBay
Tindie Blog | Spruce up Your Game Boy Advance SP With a Headphone Jack PCB