Used Headphone amplifiers

IK Multimedia Arc On-Ear

USB-DAC

iFi Audio Go link Max

USB-DAC

FiiO K11

USB-DAC, Display, gain switch

FiiO KA11

USB-DAC

FiiO K11 R2R

USB-DAC, Display, gain switch

iFi Audio Zen Dac 3

Bass Boost, USB-DAC

FiiO JA11

USB-DAC

Fosi Audio K5 Pro

Bass Boost

FiiO K7

USB-DAC, gain switch

Fosi Audio K7

Display, Bluetooth

FiiO BTR15

Microphones, USB-DAC, Tone control, Display, gain switch, Bluetooth

BOSS (Electronics) Katana:GO

Display, Bluetooth

FiiO BTR17

Microphones, USB-DAC, Tone control, Display, Bluetooth

iFi Audio GO link

USB-DAC

Mackie Hm-4