Your search for headphone amplifier returned the following:

Digital-to-analog converter/headphone amplifier for iPod touch®, iPhone®, and iPad® (Silver)

IN STOCK

20 people say 

• desktop digital-to-analog converter exclusively for use with iPod®, iPhone®, and iPad®
• built-in high-quality headphone amp
• coaxial digital and analog audio outputs for connection to a stereo, home theater system, or powered speakers

Digital-to-analog converter/headphone amplifier for iPod touch®, iPhone®, and iPad® (Red)

LOW STOCK

20 people say 

• desktop digital-to-analog converter exclusively for use with iPod®, iPhone®, and iPad®
• built-in high-quality headphone amp
• coaxial digital and analog audio outputs for connection to a stereo, home theater system, or powered speakers

Stereo digital-to-analog converter/headphone amp/preamp (Black)

IN STOCK

6 people say 

• twin Wolfson 24-bit digital-to-analog converters plus Adapted Time Filter 2 for reduced jitter
• digital audio inputs — optical, coaxial, and asynchronous USB (Type B)
• built-in headphone amplifier and volume control

Stereo digital-to-analog converter/headphone amp/preamp (Silver)

IN STOCK

6 people say 

• twin Wolfson 24-bit digital-to-analog converters plus Adapted Time Filter 2 for reduced jitter
• digital audio inputs — optical, coaxial, and asynchronous USB (Type B)
• built-in headphone amplifier and volume control
  

Plug-in asynchronous USB digital-to-analog converter

IN STOCK

12 people say 

• 24-bit/96kHz ESS Sabre™ digital-to-analog conversion chip
• asynchronous USB data transfer for reduced timing jitter and better sound
• 3.5mm stereo minijack provides direct headphone connection, plus fixed or variable line-level output

Case and headrest mounting kit for iPad® 2 and 3 — includes transmitters for wireless headphones and FM radio

IN STOCK

• includes 12-volt power adapter
• installs without tools onto most adjustable/removable 2-post headrests
• mount allows charging of iPad when used in conjunction with iPad case and 12-volt power adapter