https://makezine.com/article/home/ir-remote-stereo-volume-c/
IR remote stereo volume control - Make:
Dec 24, 2006 - Andy shows you how to build a simple IR remote stereo volume control - pictures, schematic and firmware source included." - Link.
stereo volume controlir remotemake
https://www.newegg.com/hamiltonbuhl-st1bk-over-the-ear-black/p/12K-02UW-00044
HamiltonBuhl Smart-Trek Deluxe Stereo Headphones with In-Line Volume Control and 3.5mm TRS Plug...
Buy HamiltonBuhl Smart-Trek Deluxe Stereo Headphones with In-Line Volume Control and 3.5mm TRS Plug (ST1BK) - Black with fast shipping and top-rated customer...
https://www.newegg.com/manhattan-usb-speakers-computer/p/19S-08G9-005H2
USB Powered Stereo Speaker System - Small Size - with Volume Control & 3.5 mm Audio Plug to Connect...