TUBE mini Balanced Headphone Amplifier / DAC — Woo Audio
Amazon.com: PROZOR HiFi Headphones Amplifier with Bluetooth 5.0 Receiver, Portable 3.5mm Headphones Amp with Volume Control and Louder Sharper Gain Switch for MP3 MP4 Mobile Phones Computers PC etc : Electronics
Z10e Electrostatic Headphone Amp / Integrated Amp - Vacuum Tube Electrostatic Headphone Amp by Linear Tube Audio
Fosi Audio DS1 DSD512 HiFi USB C DAC ES9038Q2M Mini Audio Headphone Amp Adapter Supports 32bit/768kHz with 4.4MM and 3.5MM Dual Headphones Outputs Compatible with Smartphones/Laptop/PC/Music Players - Walmart.com