Buffer PCB

A tiny buffer circuit to use as part of another circuit or by itself. Simple layout and clean sound with unity gain. Use on boards with many true bypass pedals, or to buffer a longer cable run to prevent signal loss. Includes the circuit board only.

The LED positive leg connects to the "LED" pad, and the negative lead connects to power supply ground. The 6k8 resistor may be adjusted to a higher value for a more dim LED, or lower value for a brighter LED (330 Ohms minimum for 9V). If no LED is required, the 6k8 resistor may be omitted and the "LED" pad requires no connection.

The circuit may be run at 9V or up to 18V with the parts listed below.

• Measures 29x19mm

Parts List

(1) TL072CP Op Amp
(1) 1N4001 Diode (any 1N4X series diode may be used)
(2) 0.1uF Box Film Capacitor
(1) 6.8K Metal Film Resistor
(2) 2M Metal Film Resistor
(1) 10uF Audio Capacitor (link to high quality audio capacitor - recommended for audio path, but any 10uF capacitor may be used)
(1) 100uF Capacitor for 9V power or 25V 100uF Capacitor for voltages up to 18V (larger part may be a tight fit)

Additional Off-Board Components

(1) LED
(1) LED Bezel
(2) 1/4" Mono Jacks
(1) Power Jack
(1) Enclosure of your choice