Under 100$

Type: DAC 

Input: Optical / COAX

Headphone-out: n/A

Line-out: RCA / 3.5mm

Type: External Soundcard (DAC+ADC+Amp)

Input: USB / 3.5mm mic

Headphone-out: 3.5mm

Line-out: 3.5mm

Type: DAC

Input: USB

Headphone-out: n/A

Line-out: 3.5mm

Type: DAC + Amplifier

Input: USB / Optical / COAX

Headphone-out: 6.3mm

Line-out: RCA

Type: DAC + Amplifier

Input: USB

Headphone-out: 3.5mm

Line & Digital-out: 3.5mm / COAX

Type: DAC + Amplifier

Input: USB / AUX via RCA

Headphone-out: 6.3mm

Line & Pre-out: RCA