It’s often pitched as a selling point, but exactly what is true bypass?
If you read guitar magazines, then you’ll no doubt be aware of many opposing stances regarding gear. String gauges, fretboard material, valve types… you name it, and guitarists will debate it.
In several circumstances, these arguments take place based on information gleaned from previously read arguments (which in turn, garnered their opinions from read arguments). The result is often that information gets a bit skewed, through the ‘Chinese whispers’ of forum opinions.
True bypass is a case in point. This is often pitched as a selling point for guitar pedals, and many forum dwellers would see this as cut and dried case- true bypass is better than the main alternative, buffered.
The truth is not quite so simple, however, and there are situations where each is the better option.
To clarify things, we have a mini guide to the difference between the two…
To understand what exactly these two bypass modes are, we need to understand what an effect pedal is doing when it is switched on. Basically, it is routing the input signal through the effect circuitry, and out through the output having been processed. In many ways, it is the ‘output’ part of this process that is key to the difference.
True bypass works by having the effect circuit as an entirely separate circuit. When engaged (switched on), the effect circuit is switched on; the input is routed through it, and then routed to the output.
When disengaged, it is as if a single wire runs from the input to the output. The effect circuit is disconnected completely, hence the name ‘true bypass’. True bypass is usually a feature of more ‘boutique’ pedals. Some (such as some of those by TC Electronic) offer a choice of true bypass or buffered.
- True bypass provides the shortest, most direct signal path, and so, the cleanest tone.
- Your tone should be exactly the same on the way out as it was on the way in.
- Because guitars (specifically those with passive pickups) are high impedance devices, running a cable over about 18.5 feet in length will degrade the guitar tone before it reaches the amp. Active pickups with low impedance outputs are less affected by this ‘tone sucking’.
- True bypass circuits can be noisy when switched on or off.
Buffered pedals take a slightly different approach. When disengaged, the signal is routed to both the output, and the effect circuit simultaneously- the effect circuit is not connected to the output, however. When switched on, the effect circuit is connected to the output.
This means that the signal is clean and consistent, regardless of whether the effect is on or off, over cable lengths that are longer than 18.5 feet. Boss pedals are (to my knowledge) all buffered.
- Cables can be run for much greater lengths without affecting outputted tone.
- Switching is much quieter.
- Can rectify the tone degradation caused by long cables when used with true bypass pedals.
- They can also act as a kind of DI, allowing high impedance guitars to be hooked up to low impedance inputs, such as those on mixing desks, without affecting tone.
- The buffered circuit can affect inputted tone (tone sucking).
As you can see, there are advantages and disadvantages to both methods of bypass. Using a combination of both can often work well, however- using a buffered pedal at the start or end of a chain can fix some of the issues of true bypass.
Whichever pedals you choose, it pays to know the differences… 😉
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