Why have some amps an effects loop (send & return)?

Why have some amps an effects loop (send & return)?

The effects loop, in short FX-loop is very useful in specific situations.
It’s two jack connectors on (mostly) the back of many guitar amps, labeled “Send and Return”.
We’ll explain which effects pedals you should place inside or outside the FX-loop, and why.

What is the advantage of an FX-loop?

The main advantage of an FX-loop is that it enhances the sound of some of the effects pedals.
It is especially noticeable with modulation and time-based effects placed within the loop.
These effects aren’t colored by the preamp, resulting in a clearer, more defined sound.
Would you prefer a tube amp and want to know how tube amps work, check this blog about tube amps.

Where in the amp is the FX-loop located?

The FX-loop in a guitar amplifier is located between the preamp and the power amp.
It’s designed to activate effects after the preamp, but before the power amp. This is important because certain effects—like delay and reverb—sound much better when applied after the gain (distortion).

Instead of placing your effects directly between your guitar and the amplifier’s input, you split the signal:

The preamp section provides the tone and distortion of your amplifier.
An FX-loop sends the signal to your effects and back again.
The resulting signal goes through the power amp and then to your speaker.

Which effects should you place in the FX-loop?

We have a few tips here. No hard and fast rules. Use them to your advantage!

Within the FX-loop: modulation- and time effects

Place modulation effects like chorus, flanger, and phaser within the FX-loop.
These effects create a spacious sound that works best when applied to the amplified signal after the preamp.

Time-based effects, such as delay and reverb, are also placed in the FX-loop for this reason. This produces the most natural sound.

Before the FX-loop: gain effects

Gain effects, such as overdrive, distortion, booster, compressor and fuzz etc., are often placed before the preamp.

This is because they work best when applied directly to the unamplified signal. These effects can also give the amplifier’s preamp an extra boost and contribute to the overall tone of the amplifier.

Is modulation also time-based?

Yes, kind of.
Modulation feeds a slightly delayed copy of the incoming signal into itself and varies the size over time in short.

Time-based effects take the original sound and delay it. Often mixing it back with the original to simulate rooms, halls, or echoes etc. 

Compressors and equalizers?

Compressors and equalizers are mostly placed before the preamp to achieve a more reliable response.
However, equalizers are also placed within the FX-loop to specifically influence certain frequencies of the final signal.
For example, think of a mid-boost to help your guitar solo cut through the mix better.

Serial vs. parallel FX-loop

1. Serial FX-loop

This is the most common. The entire signal goes through the effects chain and returns.
The disadvantage: if an effects unit adds noise, you’ll hear it throughout the signal.

2. Parallel FX-loop

This mixes the dry (unprocessed) signal with the wet (effects) signal. This preserves the punch of your direct tone. This is especially useful with time-based effects like delay and reverb.

Not every guitar amp offers this option—some more expensive models do. With a parallel loop, you need to be able to set the effects to 100% wet to prevent phase issues.

Are there specific amps that provide FX-loops?

You really only need to use it if you’re getting your distortion from your amp itself (instead of a pedal) – it allows you to place effects after the amp’s distortion for a more natural reverb and delay sound.

No FX-loop for clean sounding amp?

Essentially, this means that if you keep your amp sounding clean, you don’t really need an FX-loop.

This is why, for example a Fender Twin Reverb doesn’t have an FX-loop, nor does the Deluxe Reverb Amp.

With these types of amps, all FX pedals go through both the preamp and the power amp.

How do you connect everything?

The guitar signal goes to one or more gain- effects and then to the input of the guitar amplifier.
The signal then goes through the preamp inside the amp and then out through the Send jack.
After passing through the modulation- and time-based effects, the signal returns to the amplifier via the amplifier’s Return jack.

The signal is further amplified by the power amp inside the amplifier, after which the final sound is heard.

The right guitar effects pedal order

You will find all information about this interesting topic in our blog about guitar pedals.

What else is important when you are looking for great sound

Please note that many many things are substantial for creating great guitar sounds. We cannot mention everything, but besides a good guitar it could be as follows;

Guitar amps explained

A good guitar amp, whether it is a solid-state or tube amplifier. Think of effects pedals, cables and guitar picks as well.
Want to know more about how tube amps work? And when you always wanted to know what “headroom” means, please read the Headroom special.

Guitar effects pedals explained

Not only the brand or type of pedals (buffered pedal or true-bypass), but the way you place them in the guitar effects pedals chain is important as well. As an example; Did you know this about compressor pedals?

Open- or closed back guitar speaker

Read about the advantages of those 2 types of guitar speakers. Both have a huge impact on guitar sound. More information about this will be explained here.

The right guitar picks

Many people think that a guitar pick is just a simple piece of plastic; the thinner & cheaper the better.
I thought exactly the same for probably 10 years since I started playing guitar. Until a certain moment I went experimenting with different materials and thicknesses.

Well, guitar picks make a huge difference on your sound and on your playing style.
Thicker picks have more mass and definitely sound different than thin flexible picks.
When using extra thick picks, you might want beveled edges for gliding on and off strings with less effort.

You may read the story of ChickenPicks guitar picks at the About page on our website and there you will also find information on all of our different models.

What others say about ChickenPicks guitar picks

Musikhaus Thomann
Chicago Music Exchange
Guitarpickreviews.com
Anatomy of guitar tone

Product descriptions:

1. Bermuda XL:
2. Bermuda III-P:
3. Badazz III:
4. Bermuda III:
5. Light:
6. Regular:
7. Shredder:

Guitar essentials:

In guitar essentials we write about interesting things every guitarist should know a bit of, especially when you’re new to (electric) guitar.
We definitely don’t dig deep into theories or technical aspects.
You will find many scientific documents about anything somewhere on the internet.