Behringer HPS3000 Studio Headphone 4-Pack with Amp | PSSL ProSound and Stage Lighting
DACS Clarity HeadLite 3+ Four Channel Headphone Amplifier with Balan
Rolls HA43 Pro Four-Channel Stereo Headphone Amplifier HA43 PRO
PreSonus HP2 Personal Headphone Amplifier Battery-powered Stereo Headphone Amp with XLR Inputs, 9V Battery or DC Power Supply, and Belt Clip - Musical Garage SCH
Used Mackie Big Knob Passive 2x2 Studio Monitor Controller/ headphone amp | Sweetwater's Gear Exchange