by Rick Carson
PART ONE: SIGNAL FLOW
The tuner shows the notes. The amp hums with 60hz of electricity. But nothing is amplified when the guitar strings are struck.
Where is the sound? Stuck somewhere along the way in the signal flow, a building block around which everything in the audio world is built. Knowing the ins and outs of signal flow will help you logically troubleshoot issues like this.
My name is Rick Carson, one of the guys behind Make Believe Studios. I produce and mix records for a wide range of artists. I started out as a guitar player, and my knowledge of signal flow starts and stems from there. I used to have to keep track of just one chain, my own guitar signal. Now on average, I am looking after 128 chains of audio at a time.
So what exactly is signal flow? Here’s an example of a guitarist who plays a Fender Stratocaster with a Boss TU-2 tuner and a Marshall stack: Strat pickups ➔ instrument cable ➔ tuner ➔ instrument cable ➔ amp head ➔ speaker cable ➔ cabinet.
This, for another example, is how Jimi Hendrix was plugged in at Woodstock:
If you wanted to add in a delay pedal, it would go after a tuner. If you’re patching in a delay on the insert of a vocal track, signal flow would come in handy when deciding whether it's pre- or post-compression.
The edge you will gain from understanding your signal flow will come from the time you spend troubleshooting your equipment. So let’s return to the guitarist from the beginning. What is stopping the signal from reaching the amp?
I know from personal experience there is a 90 percent chance that the issue is the instrument cable connecting the tuner to the input of the amplifier. How do I know this?
Let's start at the top. The guitarist straps his guitar on and turns on his tuning pedal. He is seeing signal there, which means the signal flows from the output of the guitar to the tuner. If it didn't, the logical solution would be to change the instrument cable between the guitar and tuner. Right? No, the first place to start would be the top of the chain of signal flow, meaning the guitar’s volume pot could be the culprit. No one wants to change out all of their cables just to realize they forgot to turn up the volume.
I also know there's not an issue with the amp as the guitarist can hear that making noise. Which brings us to the instrument cable connecting the tuner to the input of the amplifier, where we find the ultimate fix. The problem here is solved, but think what would happen with a break in signal flow here:
I know this may not the easiest concept to understand at first, but it will be a recurring theme in all of the new Gear Nebraska posts. Every audio example will have signal flow, and I will do my best to describe them. If there is ever a question on the signal flow of something, please reach out and let us know.
As far as questions go, we are going to cover all sorts of things on the new Gear Nebraska. If there is anything you would like to know about, from drum heads and tuning tips to how to align an analog tape machine, we would love to hear from you and bring these discussions to other people in the hopes it may be able to answer some of their questions, too.
In the meantime, review signal flow and then read up about the related concept of pedal chains further below.
House of Loom's signal flow:
PART TWO: PEDAL CHAIN
The term pedal chain refers to the order in which you have you pedals strung together. They flow one into the other and while they are a small spot in the chain, their order does indeed matter.
The first pedal in the chain most of the time will be your tuning pedal. It’s much easier to tune a clean sounding guitar than a distorted one, and your pedal thinks about it the same way.
After that, we get into the fun stuff.
Tuner ➔ wah ➔ compressor
Why does the wah go before the compressor?
A wah is what is technically known as a user-controllable bandpass filter. It rolls out the highs and lows drastically while letting the mids pass through. You are then able to shift this preset equalizer around and get your wah-wah effect. The wah causes a shift in volume because of the lack of low-end. The compressor being after the wah will help even this tonal shift out at least volume-wise.
Tuner ➔ wah ➔ compressor ➔ distortion
There is a pretty good reason for having your distortion placed here in the chain. It has to do with the time-based effects that usually will follow afterwards in the chain.
You want to distort your sound and then added delay and reverb to give it space. You usually don't want to create a space and then distort it. This tends to make a pretty big wash of distortion.
Modulation pedals such as flangers and phasers should come after the distortion but before the reverb and delays. This has to do with the same principles we discussed about in terms of distortion. You want to create the sound and then add space to it, not flange a room.
So we have tuner ➔ wah ➔ compressor ➔ distortion ➔ modulation ➔ time-based effects.
THE EFFECTS LOOP
What the hell is it and what is it used for? The effects loop on an amp is much like the effects send and return on a mixing console. You use it to send from the preamp out of your amp to your time-based effects and then patch back in before the power amp section of your amplifier.
This is a great spot for reverbs and delays. It can make them blend in better and will give a more consistent sound to your reverb and delay because it will take the output changes of other pedals out of the equation.
As always, these are guidelines, not rules. Throw a compressor into a wah and listen to what happens. Who knows, it may be perfect. Also, when recording guitar, it is best to use only the pedals you absolutely need for the sound you’re recording at that very moment.
Rick Carson is a Hear Nebraska contributor. He is also a member of Fear Nebraska, the dodgeball team that will triumph this Sunday at The Bourbon. Reach him at firstname.lastname@example.org.