You'll see it written in a lot of our product descriptions - 'true bypass'. But what does it mean?
Even if you have pedal(s) on your board turned off, the signal from your guitar has to go through them on its way to the amp.
And it's HOW the signal goes through a pedal that determines whether it will degrade before it reaches the end of the route.
Avoiding tone suck
With true bypass pedals, the use of a DPDT (dual pole dual throw) switch allows the signal to take a route around a pedal's circuitry when it's turned off, rather than having to go through it like it would when the pedal is activated. This avoids the internals of a pedal 'sucking tone' from the signal.
In many situations - such as if you're playing at home where a long guitar cable isn't necessary, or if you only gig with three or four pedals - true bypass pedals are the perfect choice for preserving your guitar's tone before it reaches the amp.
If, however, you need a longer cable for stage use or you have more than a handful of pedals on your board, you can run into trouble with true bypass pedals.
Impedance is the enemy of tone, and long cable runs (either a long guitar cable, or multiple patch cables between pedals) can seriously affect your signal, whether or not your pedals bypass their internal circuitry.
The key is to include a buffer in your setup - this can either be a pedal which is not true bypass (these are known as buffer bypass because they amplifiy or 'buffer' the signal to help it through a pedal's internal circuitry with minimal loss), or a standalone buffer/signal conditioner.
Strengthening the signal in this way enables longer cable runs to be used without losing treble or clarity in your tone, and most people place them at the beginning of their pedal routing.
So, to conclude...
Don't let the terms true bypass and buffer bypass put you off buying a pedal. Yes, true bypass is a great feature but having too much of a good thing can be detrimental to your tone. Use a dedicated signal conditioner or a buffer bypass pedal along with your true bypass pedals for the best of both worlds - pure, clean signal reaching your amp is the key, after all.