Gibson Tone Tips: True Bypass Pedals and The Buffer Zone
There’s a lot of talk these days about “true bypass” effects pedals, and many manufacturers advertise as a major selling point the fact that they include this function. The subject isn’t entirely as clear-cut as it might seem, however, and there’s more to the issue of true bypass than a simple good/bad dichotomy. Let’s take a quick look at what “true bypass” actually means, and why it might be good for your pedal set up—and why, sometimes, it might not be.
When a manufacturer says one of its pedals is “true bypass”—also sometimes called “hard bypass” or “hard-wired”—it means that when the pedal is in the off position the un-effected guitar signal is routed directly from the pedal’s input jack to the output jack via the stomp switch, rather than flowing through some portion of the pedal’s circuit.
This would seem the normal way of doing things, but until recent years the majority of effects pedals were in fact not true bypass. Achieving true bypass is more complicated than it might seem, especially when you also want to have some form of LED status light on the pedal to show you whether the effect is on or off. Each of these functions requires a portion of the on/off stomp switch, and switches complex enough to achieve both true bypass and LED on/off functions haven’t been available until relatively recently, and are still pretty expensive parts. In the past, therefore, it was easier for manufacturers to use the simpler stomp switches available to switch a portion of the effect’s circuit on and off, while still routing the signal through part of the circuit in the “off” state. To the ears of some players this can sometimes weaken or thin out their guitar tone, even when an effect is supposedly “off,” resulting in a condition commonly referred to today as “tone sucking.” When you switch a true bypass pedal to off, on the other hand, you route the signal along its way from in jack to out jack via just a few inches of wire and terminal connections, a state that should result in a tone that is totally un-sucked and indistinguishable from the tone you get when you plug straight into the amp.
True bypass’ ability to boast reduced or non-existent tone-sucking is its major selling point, and it would therefore appear to be a universally good thing. In some cases the feature is a great virtue, sure. In others, however, a fleet of pedals that are all true bypass doesn’t always achieve the best straight-sound results.
Before true bypass became a tonehound watchword, some pedals without it routed the signal through a tone-depleting portion of the circuitry (they didn’t mean to do this, they just didn’t know better), which is most notoriously the case with vintage wah-wah pedals. Others, however, made a virtue of the fact that the signal needed to pass through part of the circuit even in the “off” state, and used a buffer stage to help maintain signal virtue whether the pedal was on or off. Put simply, a buffer is a basic preamp, although one that doesn’t add any gain to the signal, but instead coverts it from high to low impedance and gives it the “juice” to make the rest of the journey through long cable runs and complex circuitry without loss of tone or level. Done right, a buffer shouldn’t change the tone of your signal, just slap it on the butt and send it on its merry way with a little more spring in its step. This might sound like new territory, but I’m willing to bet you have encountered buffers without even knowing it. Many classic pedals contain them, including the great Ibanez Tube Screamer and Analog Delay series, all of the classic-format Boss pedals, recent pedals from Visual Sound, and others. High-end British pedal maker Roger Mayer even puts a choice of outputs in many of his new designs, giving you the option of true-bypass or buffered operation.
So if true bypass is hailed these days as being so universally wonderful, why would we want a buffer in any pedal? Well, with just a few pedals on the floor and relatively short cable runs from guitar to pedals and pedals to amp, true bypass will often yield the best results. Now, consider the scenario of a pedalboard with 10 or more different pedals on it —not at all uncommon these days—a 20ft cable from guitar to pedals, and another 20ft cable from pedals to amp. Any guitar cord of 20 feet or more imposes a load on your signal that depletes the high end in particular, but is generally heard to be dulling down the overall tone slightly. Two of those can really sap your highs, then run that signal through 20 or more input and output jacks, 20 switch terminals and the contacts between them, and several inches of wiring within each unit to make the true bypass connections, and that’s a lot of tone sucking. If you own even a handful of true bypass pedals yourself, try it out: connect together as many as you can find (switched off), use a long guitar cord on either side, and check your tone. Now unplug at the amp, plug straight in with just one cord, and listen again. Hear the difference? In this scenario, the wonderful true bypass itself is depleting your tone.
Put a buffer stage toward the front of that loaded pedalboard, however, or even at the end of the chain, and the buffer makes the rest of the wiring and cable length after it “invisible” to your signal. Your tone is unlikely to travel through any crowded pedalboard totally unchanged, whether buffered or true bypass, but in most cases a buffer stage will preserve clarity and definition that improves your final overall sound. Any touring pro player with more than a pedal or two on the floor knows this all too well. Sure, they might use three racks full of true bypass pedals—and the fact is that many of the most desirable pedals made today are indeed true bypass—but you’ll find they either have a buffer or preamp to drive those long cable lengths, or they run through a custom-made switching system that has its own buffering, and which takes the pedals out of the loop when they’re not on. Otherwise, a loop switcher is a good way to simplify the routing and cut down your total wire lengths in the “off” state, although you still have your total guitar-pedals-amp cord lengths to consider.
True Bypass vs. the Buffer Zone? Not necessarily. Both can work hand-in-hand to achieve the most desirable results. Explore for yourself, see what works, and keep an open mind to tone rather than jumping feet first onto the hype wagon.
[originally by Dave Hunter | 12.31.2007, Gibson.com]