When a pedal is off, your signal still has to get through it. How it does that is called the bypass, and there are two main types.
- True bypass. When the pedal is off, a switch connects the input jack straight to the output jack. The circuit is out of the path completely.
- Buffered bypass. When the pedal is off, the signal still passes through a small circuit called a buffer. A good buffer doesn't color the tone; it makes the signal strong enough to travel without losing detail.
The cable problem
Your guitar pickups produce a weak, high-impedance signal. Every cable acts a little like a capacitor, and capacitance shaves off high frequencies. The longer the total cable run, the more top end you lose.
With a board full of true bypass pedals, all switched off, your guitar sees one long cable: guitar cable, every patch cable, the switch contacts and the cable to the amp. Add it all up and the sound can get noticeably darker and less lively. Many players don't notice until they plug straight into the amp and hear the difference.
Why one good buffer helps
A buffer turns that fragile signal into a strong, low-impedance one that can drive long cables without losing highs. You only need one, placed near the start of the chain, often in the tuner or a dedicated buffer pedal. Some players add a second one at the end to drive a long cable to the amp.
More buffers aren't better. A chain of cheap buffers can add noise or change the tone slightly, so pay attention to which pedals have them.
Fuzz and buffers
Vintage-style fuzzes, especially germanium Fuzz Face types, want to see your guitar pickups directly. A buffer in front can make them sound thin and harsh, and the guitar volume knob stops cleaning them up nicely. Put that kind of fuzz before your buffer.
The takeaway
Neither type is better on its own. True bypass is great on a small board with short cables. On a bigger board, one good buffer near the start keeps your tone bright. Use your ears, not dogma: compare your board with all pedals off against a straight cable and decide.