Guitars and amplifiers have been around for a long time now, particularly guitars, which have been a part of human history for thousands of years in different forms. Amplifiers, on the other hand, are significantly newer.
As guitars increased in popularity over the last century, so did the effects that guitarists used with them. When we added overdrive and distortion into the mix, the tone could get messy due to the combination of direct effects in front of the amp. This is where the FX loop comes in – but which one’s better?
Generally speaking, it’s best to put modulation, time-based, and looper pedal effects in the effects loop on the back of the amplifier. Guitarists usually put their dynamics processing and distortion in front of the amp, rather than in the effects loop (aka, FX loop). There are no rules though.
Ultimately, where you put your effects and dynamics processors depends on what you’re after. For example, I think it makes a lot of sense to put your time-based and modulation effects in the back of the amplifier (FX Loop), and then the distortion in the front. Now that we’ve gotten the brunt of the topic out of the way, let’s really dive into it down below.
How A Guitar Amp’s Pre-Amplifier and Power Amplifier Work
It’s useful to briefly explain the basics of how a guitar amplifier works before we get into FX loops and direct inputs. In fact, it’s more than useful. It’s essential for understanding what an FX loop is.
Guitar amplifiers are often described as having two stages, the pre-amplifier stage and the power amplifier stage. A guitar signal is almost always super weak. Anyone who has ever recorded a direct track into their Scarlett 2i2 (on Amazon) knows this.
Because it’s so weak, it has to be brought up to a level that’s suitable for the power amplifier to actually grab onto and then turn into sound for everyone to hear. This “suitable level” is usually called “line level.”
This is usually +4dBU. Compare and contrast this to instrument level which is usually measured around -30dB. As you can see, there’s a big difference between the two.
The pre-amp in your guitar amplifier is jacking that signal way up to a line-level so the power amplifier has something to work with. Otherwise, the power amplifier wouldn’t be able to do anything with it.
In simple terms, the preamplifier stage is the part of the signal path where the guitar signal is increased, equalized, and affected by the general settings of the amplifier. Once the audio signal has been processed by the pre-amplifier, it’s sent to the power amplifier.
The power amplifier is the final stage of amplification before the signal is sent out through the speakers. Distortion and overdrive are usually created in the pre-amplifier section of the guitar amplifier. This brings to me the next section on the FX Loop.
What’s the Difference Between An FX Loop and Direct?
I think it’s worthwhile to define what these terms actually mean. For example, when guitarists use the term, “direct,” it can be confusing to some people.
What they mean by “direct,” is putting the guitar pedals and effects in front of the amplifier as part of the regular amplifier > cable > pedals > cable > guitar signal chain.
This means the effects, dynamics processing, and overdrive are a part of the guitar amplifier’s regular signal chain. The FX Loop (aka effects loop), on the other hand, is behind the amp in the FX loop.
Guitarists put their effects in the back end of their amplifier, away from the signal chain in front of the amp. However, I feel like this isn’t the best way – or the most accurate way – of explaining what’s going on here. Here’s a better description of the FX Loop:
The FX loop refers to the signal being sent out of the guitar amplifier after the pre-amplifier stage to be affected by an external effect unit, and then back into the amp before it’s amplified by the power amp. Direct refers to putting the effects after both the pre-amp and power amplifier stage.
Which Pedals Should Go Through The FX Loop?
Generally speaking, it’s best to put modulation, time-based effects, and looper pedal effects in the FX loop of your guitar amplifier. The reason is that you get the best of both worlds – an amplifier capable of overdriven sounds without sloppiness, but also clean modulation and looper effects.
The reason for this is then you have the ability to record an effects-laden loop, and then jam over the top of it with a dry signal. If you don’t use the FX Loop for this, what ends up happening is that you turn your effects pedals off, and then also turn off the effects on the loop as well.
That said, there are many people who are probably looking for that. But I’m not one of them because I love using my looper pedal for practice sessions and creative sessions. I prefer having more control over my tone.
When Is It Better To Put Pedals In Direct Input (In Front of the Amp)?
For most guitarists, it’s best to put dynamics processors, overdrive, and distortion in the front of the amplifier, or via direct input, which is part of the regular guitar and amplifier signal chain. Guitarists often put time-based and modulation effects in the effects loop.
This is just a general rule of thumb. Like I said at the beginning of the article and in my article on loopers and FX loops, there aren’t rules – there are just common ways of doing things.
Important Things to Note About Direct Vs FX Loop
1) There Is More than One Way of Using Effects
Like I said earlier, I like to put my BOSS RC-5 Loop Station in the effects loop of my amplifier because I enjoy the freedom of being able to turn the effects on and off while jamming over a loop.
But there are different ways of doing things, and it ultimately depends on what you’re doing, which brings me to my next point.
2) There Are Different Kinds of Effects Loops (and Levels)
There are other kinds of effects loops as well. For instance, there are serial effects loops and parallel effects loops. Others have line-level effects loops (+4dB) while others have instrument levels (around -10dB to -30dB).
Simply put, series effects just mean your signal is going from effect pedal to effect pedal, one after another (serialized). A parallel effects loop, on the other hand, is when the wet signal is mixed in parallel with the dry signal, simultaneously.