This is a simple do-it-yourself (DIY) headphone amplifier project that is fashioned primarily after the Class A MOSFET Headphone Driver project by Greg Szekeres and to some extent Mark’s DIY Class A 2SK1058 MOSFET Amplifier Project. The amplifier concept is simple and follows a typical single-ended class A circuit utilizing an active constant current source (CCS) in place of a passive resistor. A CCS doubles the efficiency of the circuit over that where a passive load resistor is used, bringing it to a maximum of 25%.
Class A Headphone Amplifier Boost Your Sound: [Link] - [via]
CMoy is a very simple and portable headphone amplifier. The amplifier was originally posted by Chu Moy on headwize.com. Headphones amplifiers are usually used when the output of a device is to low for the kind of headphones you’re using, or to get better sound quality by keeping the device on a medium volume setting and amplifying the sound with the headphone amplifier. I’ve not build this amplifier so far, so i cant tell you from my personal experience if it sounds good or bad, but from what i read on the internet, users that build it are very happy with the results. The schematic is very simple, parts are easy accessible so it should go really smooth with the building process if you decide to do it.
CMoy Headphone Amplifier: [Link]
TDA2005 2×20 Watt Stereo Amplifier description:
This circuit is a small stereo amplifier for all suitable applications like amplifying small speakers, boxing, etc. It is also suitable for car use but before, the power supply must be choked with at least 150mH and it must give up to approximately 6 to 7 amps during the upstream performance.
Appropriate heatsink for the amplifier is SK08 with a height of 50 mm (approx. 2.5 K per watt). You should drill the cooler after soldering the board to center it properly. The TDA2005 also needs not be isolated from the heat sink, since the metal mounting part of the IC is grounded. You should use thermal paste to improve the heat dissipation. After the assembly , case construction is left to the builder. 100K potentiometers are used for adjusting the input volume. The potentiometers are absent in the layout. The 100K resistors need only be installed if the 100 K potentiometers are not used as shown in the layout. For full info on TDA2005 2×20 Watt Stereo Amplifier visit project page.
TDA2005 2×20 Watt Stereo Amplifier: [Via] - [schematic, PCB and layout files]
This SMD op-amp project uses the TI RC-4560 dual op-amp chip and a salt water-etched PCB. The builder got the op-amp as a free sample from Texas Instruments and scavenged all of the SMD resistors from old hard drive electronics. The results are not pretty, but they’re functional. The circuit used (with some changes) is the Chu Moy design found here. The CMoy circuit is not SMD.
RC4560-based headphone amplifier [VIA]
The 22 watt audio amplifier is an easy to build project, very inexpensive. The circuit can be used to boost the signal from a car audio system, home speaker system or as an amplifier for computer speakers. These are just a few practical applications, but it can be adapted to your personal needs. The circuit is compact and uses only about 55 watts; it dissipates roughly 28 watts of heat, so a heatsink is necessary. It operates at 12 Volts at about 5 Amps at full volume. Lower volumes use less current, and therefore produce less heat. The chip should run cool enough to touch with the proper heatsink installed. The parts can be found at any electronics store, making it a great DIY project for beginners.
Parts List:
- R1: 39K 1/4 Watt Resistor
- C1,C2: 10uf 25V Electrolytic Capacitor
- C3: 100uf 25V Electrolytic Capacitor
- C4: 47uf 25V Electrolytic Capacitor
- C5: 0.1uf 25V Ceramic Capacitor
- C6: 2200uf 25V Electrolytic Capacitor
- U1: TDA1554 Two Channel Audio Amp Chip
- MISC: Heatsink for U1, Binding Posts (For Output), RCA Jacks (For Input), Wire.
