The peace and quiet in our household has recently been shattered by the arrival of a Sega MegaDrive. For anyone who is not actually using the machine, the sound from Sonic the Hedgehog or whatever can soon become very monotonous and annoying.
http://electronic-projects.net/Electronic-Projects/projects/headphone_amp/index.htm
The amplifier operates primarily in the current domain. The first stage is a voltage controlled current sink. The second stage is a current-controlled voltage source.
http://headwize.com/projects/showfile.php?file=gilmore2_prj.htm
This amplifier was born out of a need to use two sets headphones with my computer sound-card. The design presented here is a 50mW power amplifier meant for phones with impedances of 32 Ohms and greater.
http://headwize.com/projects/showfile.php?file=balkishan1_prj.htm
This amplifier can output up to 0.5W into a 32-ohm load. It is a pure class A design containing a new never-before-seen servo loop that is not part of the audio signal chain in any way.
http://headwize.com/projects/showfile.php?file=gilmore3_prj.htm
Electrostatic headphones, like electrostatic speakers, work on a push-pull arrangement. When one of the stators is going up in voltage, the other stator must decrease in voltage so that the diaphragm can move due to the static charge.
http://headwize.com/projects/showfile.php?file=gilmore_prj.htm
The tube headphone amplifier is a high current mu follower, with a 12AU7 cathode follower driven by a 6CG7. Both sections of each tube are paralleled to minimize noise.
http://headwize.com/projects/showfile.php?file=strain1_prj.htm
This article discusses several opamp-based headphone amplifier circuits, including suggestions for selecting opamps, input coupling and filtering, high current output stages and power supply options. There are no recommendations for specific opamp brands or models.
http://headwize.com/projects/showfile.php?file=opamp_prj.htm
It can be used without any limitation as preamplifier. It can drive any kind of power amplifier, because it has enough output voltage swing, enough gain (about 30db) and a very low output impedance (about 30 ohms).
http://headwize.com/projects/showfile.php?file=ciuff2_prj.htm
Design goals for the Kumisa III: I like high bandwidth and slew rate, because it gives a high security margin before phase errors appear in the high frequencies.
http://headwize.com/projects/showfile.php?file=jorgen2_prj.htm
Excellent sound quality, simplicity, linearity and no multi-stage feedback. It is a single stage class A MOSFET design with the right gain and a low output impedance.
http://headwize.com/projects/showfile.php?file=pellerano_prj.htm