Video: Bypass Wars!
True bypass, versus non-bypass, versus buffer inputs.
Let me start by saying this: Jimi Hendrix used coiled guitar cords and non-bypassable EFX, and he didn’t have his amps biased, and somehow he managed to sound okay.
Back in the day, all EFX pedals (at least every one I’ve seen) used a similar system to minimize pops when engaging the device. To do this, they had to keep the input connected and “on” at all times. This presented a “load” to the guitar. When the effect was engaged, it didn’t much matter, but when the effect was disengaged the load that was still being presented to the guitar was of measurably lower impedance than the one the amp’s front end presented. This would change the sound of the guitar, rolling off top end and overall level. Add a few of these EFX in a line and you can see what happens: mud. It’s this system, one that really hasn’t been used in decades, that set off the current storm of Bypass Wars!
Let’s start here. The input of your average amp isn’t a benign glory-tone-hole. Averaging roughly 1m Ω, an amp’s input impedance is a compromise between the noisy super-high impedance that pickups like, and lower values that would be quiet but that pickups don’t like.
This drawing shows a simple tone control circuit. The potentiometer works in conjunction with the capacitor and resistor to change the sound. What you don’t see is that the capacitor is your guitar cable, the resistor is your amp’s input, and the potentiometer is your guitar’s volume control. This almost perfect tone circuit is why you lose treble when you turn down your guitar’s volume. Add two 20’ guitar cables and maybe a few shorties between EFX, and it all adds up.
In 1978 Boss, a division of Roland, introduced the OD-1, its first “Compact Pedal.” The OD-1, like all subsequent Boss pedals, used a buffer circuit at its input stage to help alleviate these problems. This buffer separated your guitar from whatever it was plugged into. Now, your guitar would only “see” the OD-1, whose high impedance and low noise was a delight to single-coils and humbuckers everywhere. If you used your volume control a lot, the effect was huge; if not, not so much.
Low-capacitance cables, treble bleed caps, buffer amps and more are all designed and touted in one way or another to help alleviate a situation that cannot be alleviated. Minimized? Somewhat, but the physics of it all are inescapable and no amount of marketing or hype can undo them. Damn you, physics!
So, which is better and what’s a guitarist to do? That’s tough. Me? I use a one-channel amp on 10, and use my guitar’s volume control to control everything. Sometimes it’s on 10; sometimes it’s on 2. Because of this, I use a Rivera Buff Box (I have five of them modified with a more modern and quieter chip). I like my guitar to “see” a buffered input, not the amp. Now, depending on how good, how many and how they’re arrayed, a lineup of buffered EFX boxes can get noisy. So if you’re going to use a true bypass effect, place it after that first buffered one.
Bottom line is that there is no perfect solution. As in most things there are pros and cons. And, if you use a multi-channel amp with your guitar full up most of the time, none of this really makes much difference anyway.
The Wild Card. Many old EFX units, chief among them the Fuzz Face, want to see that un-buffered signal. As I demonstrate in the video, if you use one of these older units after a buffered effect or in a loop switcher that has buffer amps (most do), you will find that your Fuzz Face or FZ1 sounds pretty awful. So what to do? Either put it first in your chain and deal with the issue I first pointed out (that’s where the Jimi comment comes in), or use a modern interpretation of one that assumes the buffered signal (like the Tech 21). I use a Boss FZ5. You may think that’s heresy, but for me, it deals with the problem and gives me great Satisfaction.