Build a buffer

Posted 2007-03-10 in Effects by Johann.

In this tutorial, I’ll show you how to build a buffer pedal.

For an introduction to buffers, see Jack Orman’s “Basic Buffers” article.

List of parts

• 1 “Buffer - IC” board from General Guitar Gadgets (US$ 7)
• 2 4.7 MΩ resistors
• 1 single channel opamp, for example a TL071
• 2 capacitors (I used one 0.47 and one 3.3 µF WIMA capacitor)
• 1 8-pin DIL socket
• 1 stereo jack
• 1 mono jack
• 9 V battery clip

In my opinion, a buffer should be always-on, so from the schematics, I’ll omit R4 and the switching. You also don’t have to use my capacitor values, it’s just that they were the biggest polyester capacitors I had laying around. The original 0.1 µF and 10 µF values are fine, too.

Soldering the socket to the board

Put the socket on the board and solder it in.

Capacitors

Solder the smaller capacitor to the left side and the large one to the right side.

Resistors

The resistors go right next to the small capacitor.

Power, audio connections and the opamp

For testing purposes, solder the battery clip and the connections to the jacks directly to the board. Don’t forget to squeeze the opamp into the socket.

Note that the opamp was accidentally reversed in the above photo. The dot on the opamp’s case should point upwards.

Connect a battery and your buffer should work. That’s really all.

Where to go from here

All that’s left to do is to wire the GND connection (the black cable on the battery clip) to a stereo jack so that the circuit will only be active when a guitar is plugged in.

Of course, you’ll also need a case, for example a Hammond 1590B or a mini Bud case.

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