Buffers

 From perfboard to PCB for a buffer circuit. 

From perfboard to PCB for a buffer circuit. 

I’m frequently asked about buffers in several differed ways, in this article I’ll attempt to outline some of the common responses to the most frequent buffer questions. Keep in mind that most of these are entirely contextual and may not be relevant to all rigs.

In its simplest form a buffer is a circuit either based around an operational amplifier or transistor that circulates the input signal through to the output with close to zero amplification.

 Buffer circuit in PCB designing. 

Buffer circuit in PCB designing. 

This circuit adds some frequency content conditioning and filtering properties and alters the impedance allowing it to pass more freely.

These changes allow the signal to pass through a long signal chain of true bypass pedals, buffered and true bypass pedals or even just long cable runs all while retaining its fidelity and most noticeably the high frequency content or “air” character of the signal.

Do I need a buffer on my board or in my signal chain?

This is both a matter of taste and dependant on the current devices in your chain.

If you have a board entirely filled with true bypass pedals then subject to your taste, you could add a buffer or a buffered pedal to restore some frequency content and manage the degradation through a large board or long cables.

Some players (including myself for certain sessions or styles) prefer to have no buffers and use the “shaping” character of impedance and the degradation that occurs giving a darker tone.

One, two, where?

For this one I have an application process I follow depending on the board I am assembling.

If I have only one buffer or one buffered pedal I will generally look to place it as early in the chain as possible.

If I have access to two buffers or buffered pedals I’ll place one at either end of the effects chain to “pre condition” and “restore” just before hitting the front endof the amp

IMG_1300.JPG

The idea of the articles in this section is to share some of the mass of information gained over a lifetime in Music, Audio, Engineering and Electronics in an effort to expand your knowledge, help you know your gear better and to have a better experience using it.

Disclaimer: The content offered through these articles is a mixture of knowledge from technical textbooks, professional education, observation and experience and is provided “as is” with no support positioned or responsibility taken.