Headbanger Amplifier:  (schematic added 10/06)

Headbanger Headphone Amp:  (diagram added 6/03)

Headphone Amplifier (circuitdb):  Both halves of the circuit are identical. Both inputs have a dc path to ground via the input 47k control which should be a dual log type potentiometer. The balance control is a single 47k linear potentiometer, which at center adjustment prevents even attenuation to both left and right input signals. If the balance control is moved towards the left side, the left input track has less resistance than the right track and the left channel is reduced more than the right side and vice versa..... (added 02/07)

Headphone Amplifier (headphone):  An amplifier to drive low to medium impedance headphones built using discrete components. (added 10/05)

Headphone Amplifier (redcircuits):  (circuit added 9/04)

Headphone Monitor Amp:  (diagram added 6/03)

Heathkit UA1:  12 watt amplifier (circuit added 11/06)

Heathkit W3AM:  (circuit added 11/06)

Heathkit W3M:  (circuit added 11/06)

Heathkit W4M:  Williamson amplifier (schematic / circuit added 11/06)

Heathkit W5M:  Williamson amplifier (schematic added 11/06)

Heathkit W6A:  Williamson amplifier (schematic added 11/06)

Heathkit W6M:  Williamson amplifier (circuit added 11/06)

Heathkit W7M:  Williamson amplifier (circuit added 11/06)

Heathkit WAP2:  Gold preamp (electronic circuit added 11/06)

HI FI Class D Audio Power Amplifier:  The purpose of this site is to share a pulse-width modulating Class D audio power amplifier design with the world, in order to involve people that have an interest in this kind of technology. This is in effect an "open source project", i.e. the design is open and free, and those that have the interest and ability, are encouraged to feed back back into the project. (added 4/02)

HI FI Headphone Amplifier:  (schematic / circuit design added 9/02)

HI FI PC Speaker System:  (electronic schematic / circuit added 4/02)

HI FI PreAmplifier:  (schematic / circuit design added 9/02)

Hi-Fi Headphone Amplifier:  (circuit added 2/07)

High Performance Audio Applications of the LM833:  RIAA Phono preamplifier stages and active crossover ne2-rks (app note added 3/03)

JT-10kb D Isolates and Converts Speaker Drive to Line Level:  (circuit / schematic design added 6/06)

Kumisa Mk. LI Headphone Amp:  DIY headph1-amplifier project using AD844 and some special transistors (added 4/02)

Leach Amp 120 Watt Power Amplifier:  Latest update of the "Low Tim Amplifier", Claimed to be a very good sounding design (added 4/02)

Leach Superamp:  270-Watt Double Barreled Amplifier published in Audio magazine (added 4/02)

LM380 Power Audio Amplifier:  National Semiconductor Application Note   (app note added 2/06)

Low Noise Balanced Microphone Preamp:  very low noise, close to the theoretical minimum, high hum rejection and variable gain with a single rotary pot, similar to that used in many professional grade mixing desks (added 4/02)

Low Noise Version of High Level Output Stage in 1031:  PDF file (added 4/02)

Low Power Audio Amplifier Based on LM386:  (schematic / circuit design added 9/02)

Microphone Phantom Power Supply:  (electronic circuit added 7/03)

Mini bench amplifier (LM386):  (electronic circuit added 2/07)

Mini Portable Guitar Amplifier:  Can be fitted into a packet of cigarettes.  Also suitable as Fuzz-box (added 3/05)

MOSFET  Power Amp:  DIY high power MOSFET amplifier200 Wrms 8 ohms -350 Wrms4 ohms (added 4/02)

MS Decoder:  (schematic added 10/06)

Ms Stereo Decoder:  (electronic circuit added 7/03)

Ms Stereo Microphone:  (electronic circuit added 7/03)

One Watt 2.3 GHz RF Amplifier using a Mrf2001:  (diagram added 6/03)

One Watt 2.45 GHz Linear Amplifier:  (electronic circuit added 4/05)