Know Your Signal Path

Guitar-nerds, like any other fetishists I suppose, love to get lost in the nuanced details and worse, converting their personal experiences into some sort of gospel to be followed. This drives me absolutely bonkers so, to the best of my abilities, I want to set the record straight. 

One of things I see people get confused by over and over again is the signal path—the electrical path from your guitar to the final sound from your speakers. This confusing situation isn’t helped by some of the snake-oil that’s sold by some equipment manufacturers and the loudest trolls on various guitar fora. Let’s start with a simple statement: there are no good or bad signal paths. There are only signal paths that make sounds you like or dislike.

So let’s break this thing down into its components. It starts with your pickups. Various pickups output different amounts of voltage and probably have the biggest affect on overall tone of your guitar. All the pedals and cable in the world can’t really make a single-coil pickup sound like a PAF humbucker, or vice versa. Don’t like the sound your getting? Are you sure you’re playing the right pickups?

Next in line is the cable from your guitar to your amp (we’ll talk about pedals in a moment). There is a lot of mystery out in the world about cables and how they’re manufactured. Some companies have done a fabulous job selling people on the idea that their cables have had unicorn tears shed upon them and thus produce a superior sound to all other cables. The truth is, most cables sound about the same. Yes, you may hear some differences, but your choice of cable is unlikely to affect your final tone.

You may find slight differences in tone between cable makers, but you’ll notice a much much bigger difference in different lengths of cable. Guitar cables are so-called “high impedance” cables, which means that the signal degrades somewhat with larger cable runs. With runs longer than about 20 feet, you’ll start to notice the high-end roll off a bit. This isn’t necessarily a bad thing, it’s just a different sound (though it may make for a noisier signal). You need to decide independently if you like it or not.

Pete Thorn has an execellent video demonstrations of how different cable-lengths affect tone (see below). Listen to the sound samples and try not to think long cables are bad. I like the tone of each of these samples. I could probably live with any of them in the right context. Long cable runs aren’t necessarily bad, but they do affect the tone.

Now, if you’re old-school, you might just plug directly into your amp. But a lot of guitarists have one or more pedals that they route their signal through to modify the sound. Here’s where things start to get a bit more complicated. Each pedal you put in the signal path can have some affect on the overall tone. Lately, a lot of manufacturers have tried to combat this by offering a “true bypass” feature which, when enabled, is sonically equivalent to the pedal not even being plugged in at all. Another feature pedal manufacturers have added is “buffering” which boosts the signal to overcome loss along the way in the signal path. Rather than trying to disappear and become transparent like true-bypass pedals, these pedals compensate for signal-loss by amplifying the signal slightly.

Relatively modern amps include a feature called “the effects loop”. This allows you to insert pedals into a different part of the signal chain. Guitar amplifiers have, essentially, two main components: a pre-amp and a power-amp. The pre-amp is often associated with having the biggest effect on the tone of your guitar, where the power amp is what sets the volume. The effects loop sits somewhere between the two and usually can be switched on or off via a footpedal.

Some people will claim that certain pedals (e.g. a flanger) simply must go in the effects loops. Hmmm. Maybe. Your mileage may vary. If you have an effects loop, you should try expirmenting with each of your pedals before the amp input and in the effects loop. For me, my pedal-board is split like this between the amp-in path and the effects loop:

 Canvas 2

Canvas 2

This sort of looks like a plate of spaghetti was dropped on the ground, so let me explain how it flows, then I’ll explain how I got here. The guitar plugs straight into a Dunlop wah-wah, which goes into a Boss EQ pedal, then on to a Boss compressor, and then to a T.C. Electronics tuner which is then plugged into the main input of the amp. The effects loop “send” goes into the MXR EVH Phaser, on to the MXR EVH Flanger, to the T.C. Electronics Chorus and into a Boss digital delay. That loop is then returned to the amp. From there, the amp sends the final signal to the power amp on finally out to the speakers in the cabinet.

The effects loop is a little “hotter” than what comes out of my guitar. To my ear, the wah-wah sounds better working with a lower voltage. I put the EQ in this part of the path because I use it for minor adjustments when I switch guitars (e.g. rolling the high-end off a bit when I go from the Les Paul to a Strat). The compressor works well here, because I use it basically like a signal boost. When I put this in the effects loop it’s way noisier. Finally, I put the tuner here to get the cleanest signal, and because it also doubles wonderfully as an on-the-floor standby switch (great for switching guitars).

One reason I use the effects loop at all is that chaining all of those stompboxes in a row starts to dampen the signal a bit. So I went about experimenting with which ones sounded good in the effects loop so I could break them up. In my experiments the flanger, phaser and chorus are all sounded equally good here, weren’t too noisy. The delay just sounded better here. I tried it in both places and, even with the gain jacked, the delay just sounds clearer in the effects loop to my ears.

I arrived at this configuration with a lot of experimentation. If you have more than one obvious signal path, don’t be afraid to play around with it a bit. Not only should you be looking for which combinations sounds the best, but also which ones sound the worst (so you can avoid those) and where it sounds the same. The title of this post isn’t some vacuous Moses-on-the-mountain commandment. When I say “know your signal path”, I mean, “know your signal path”. Nobody else’s really matters when it comes to your sound.