Shared Projects by AudioGeek

This is a power amp board for small audio amps (or anything else that needs 12V DC). It takes the output of a small transformer and rectifies it to DC. I use it with a small 120/12 1.5A Radio Shack transformer. It is designed to use the following parts (or something similar):

Bridge Rectifier (Mouser: 750-DF204-G)
LM7812 Voltage Regulator (TO-220 package)
D1 1N4001 Rectifier Diode

C1 2200µF 25V electrolytic capacitor (667-EEU-FR1E222S)
C2 0.1 µF film capacitor (647-QYS1H104JTP) - (or any similar cap with 5.08mm lead spacing)
C3 220 µF 25V Electrolytic (667-EEU-FM1E221)

R1 1.5k Ω 1⁄4W metal film resistor (lower value = more bright; higher value = less bright)
LED 3mm (whatever color you like)

Note: The hole in the board is sized for a small #4/40 bolt to attach it to a chassis with a spacer.

Fuzz pedal design based on the Bazz Fuss.

Radio Shack 273-1380 audio output transformer breadboard adaptor.

Power a breadboard with a wall wart.

2.1mm Power Jack (TaydaElectronics.com, Part# A-4118) Double row pin header (Tayda, Part# A-198) 2 position screw terminal (Mouser.com, Part# 538-39880-0302). The screw terminal can also be had cheaper at Tayda, but I wanted it in black to match the 2.1mm jack.

Those 9 volt snaps always seem to have stranded wire leads, making them hard to plug into a breadboard. Tinning the leads can make them too thick to fit.. With this you can just plug the 9 volt snap leads into the screw terminal and call it a day. Or just plug a wall wart into the 2.1mm jack instead.

NOTE: Although you see holes, the 2.1mm jack holes are actually slots, so they work with normal “solder lug” style jack slots when fabricated (notice the rectangular outlines there). You do NOT need a jack with PCB pins.

Plug a Pentawatt 5-Pin IC into a Breadboard.

I am currently working on a project using this board to plug a TDA2030 amplifier into a breadboard. Other common chip amps like the TDA2050 and LM1875 (and others) will also fit.