Used items in Headphone amplifiers

FiiO K7

gain switch, USB-DAC

FiiO K13 R2R

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

FiiO KA17

gain switch, USB-DAC

FiiO K11 R2R

Display, gain switch, USB-DAC

FiiO BTR17

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

FiiO BTR15

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

iFi Audio Go link Max

USB-DAC

FiiO Jiezi A

Tone control, USB-DAC

iFi Audio GO link 2

USB-DAC

FiiO KA13

gain switch, USB-DAC

FiiO KA11

USB-DAC

iFi Audio Zen Dac 3

Bass Boost, USB-DAC

FiiO JA11

USB-DAC

FiiO KA11

USB-DAC

Mackie Hm-4