Some lovers of High Fidelity headphone listening prefer the use of battery powered headphone amplifiers, not only for portable units but also for home table applications. This design is intended to fulfil their needs and its topology is derived from the Portable Headphone Amplifier featuring an NPN PNP compound pair emitter follower output stage.
http://www.redcircuits.com/Page137.htm
The main requirement was to power the circuit by means of a common, PP3 transistor radio alkaline battery.So, implementing a low current drawing circuit was absolutely necessary, though preserving a High Quality performance.
http://www.redcircuits.com/Page119.htm
Like the original Morgan Jones amp, the original 6N1P OTL had trouble driving low impedance headphones. This version of the 6N1P OTL amp features a re-balanced output stage that gets all of my headphones plenty loud.
http://headwize.com/projects/showfile.php?file=bender_prj.htm
Since many years back I make SMD designs at work but I have never before designed any audio with mainly SMD parts. This is my very first audio SMD project.
http://home.swipnet.se/~w-50719/hifi/qrv04/
You have to rely on the power of your power amp or your headphone out of your amp or your mixer headphone out to power it. Each channel of each headphone has a resistor in series that acts as a buffer .
http://europa.spaceports.com/~fishbake/headphone/head.htm
Extends common-mode rejection voltage range to +/-300 volt and virtually eliminates RFI problems.
http://www.jensen-transformers.com/as/as074.pdf
This article shows my tube headphone amplifier designs for driving headphones with an impedance of 200 to 600 ohms (I am using these amplifiers with the Sennheiser 580, which has a 300-ohm impedance).
http://www.headwize.com/projects/showfile.php?file=ciuff_prj.htm
Along with noise-features, the Active Noise-Canceling Headphones let you mix in an auxiliary line-level signal from a CD or tape player. That allows you to minimize background noise while quietly listening to music.
http://www.headwize.com/projects/noise_prj.htm
Because a few milliwatts will drive headphones to full volume, a great headphone amplifier design can be relatively simple. Yet, there are any number of reasons for experimenting with more complex topologies, such as improved performance and the ability to incorporate custom options.
http://www.headwize.com/projects/opamp_prj.htm
You can build a high-quality portable amplifier to boost the output of Sony MiniDisc portables. After the euphoria over receiving my new Sony Minidisc bundle had partially subsided, I noticed that the portable unit, the MZ-E40, has a rather weak output. Measurements showed that it can only manage 80mV rms output and only about 74dB SPL output from the phones.
http://www.minidisc.org/headbanger.html