How To Use An Effects Loop – Guide And Diagrams

In the early days of guitar amplification, it was easy to get a great sound from effects right through the front of an amplifier.

Most amplifiers in the early days of amplification were clean pedal platform type amps with no effects loop.

Headroom was accomplished and even sought after to get the true tone of an electric guitar.

Slowly as pre-amps began to provide break up or distortion, things began to change. Effects were slowly becoming “chewed up” by the clipping pre-amp and their sound took a rather big hit!

Today you will find one or more effects loops on most amplifiers, but most people do not understand how they work.

Effects Loop

Table of Contents

What Is An Effects Loop?

The effects loop is a circuit designed to insert stomp box effects into a predetermined position in an amplifier. Effect devices require small signals, and so the effects loop must condition them to work safely with an amplifier.

This prevented time based or modulation effects like reverb, delay, chorus or flangers from getting altered in a preamp designed to distort.

The distortion from a preamp alters time based effects so badly in some cases that the effects themselves do not sound remotely close to the way they were designed to.

The effects loop prevents this altering and provides an optimal sound from effects by inserting them after the distorting preamp and before the power amplifier.

effects loop

Why An Effects Loop Is Important

Most guitar players have effects either in the form of single pedals or multi effect processors.

Some of these effects sound incredible and do an amazing job of providing players with great sound.

But have you ever noticed that when you run delay, reverb or chorus through your drive or high gain channel on an amp, it doesn’t sound right?

In fact, if you run the same effect through your clean channel, it sound right again and like it was made to.

What you are hearing is the modified version of the effect through your distortion channel.

Now, some effects are fine through the distorting pre-amp, but anything time based or modulation is going to get altered.

This is not how to get the optimal sound from these effects and this is where your effects loop comes to the rescue.

Setting Up Your Effects Loop

Setting up your effects loop is generally quite easy. You will see that the loop has a “Send” and a “Return” jack.

Sometimes they are also labelled In and Out or pre-amp and power amp depending on the amp. 

You will want to make sure that you are using high quality cables to connect your effects or processor.

We generally recommend cables with twisted pair conductors like the D’Addario Custom Series Twisted Pair Cables.

This will make sure that you will prevent injecting noise into your signal.

Connect the “Send” jack to the input of your effects pedal or processor, and the “Return” jack to the output of your effect or processor.

If the amplifier has any send or return level controls, you will want to set these while playing your amplifier.

One thing to note however is that the send level control should be set after your pre-amps are set up.

This will prevent any signal level changes should you need to adjust your amplifiers channel controls.

When setting your send level control, keep in mind that some pedals are very sensitive to signals above instrument level signals and will generally begin to clip.

The effects of clipping will be loss of treble and a dull lifeless sound, or distortion from the effect.

Should this be the case, turn the send level down until everything sounds right.

Once you have this set, any return level controls can be turned up in conjunction with the master controls to get the desired output volume from your amplifier.

For any other questions about set up, make sure to also take a look at your amplifiers manual, this will help should you get stuck!

4 cable method

Distortion Is Hurting Your Effects

There are some incredible drive channels or even high gain channels from today’s amplifiers. The sound and feel can really inspire players.

But most players make the mistake of putting all their effects through the front of the amp!

You see, the distorting pre-amp is altering your guitars signal so much by clipping the signal that it can also alter the effects. 

Not only do the amps drive channels alter the signal by distorting it, there is also a level of filtering. This filtering changes frequencies of your original guitar signal.

This can only be disastrous to a great tone from your precious petals because it changes them as well!

So that great chorus pedal you bought because it sounds so good on the clean channel.

Hate to say it, but if your using it in the front of your amp and on the drive channel, it’s not the same anymore.

Give it a try.

Below you can see what the signals looks like electrically. On the left is a clean signal which is normally what you will see coming from an instrument, but far more dynamic.

On the right is a signal that has been clipped or distorted, this is what the signal from a distortion or overdrive channel would like like.

As you can see the top and bottom of each wave has been clipped off.

This clipped off part of each wave is essentially lost information if you will.

And so if your time based effects go into the over driven channel, you can imagine what might happen to them once the pre-amp spits them out.

Amp's Effects Loop

Different Types OF Effects Loops

Once amp manufacturers began including effects loops on their products, players could then begin running sensitive effects through them.

This allowed the amp to voice the distorted signal and then run that new tone through the effect.

This keeps the sound of the effect intact and optimal just like it was designed to be.

But there are two types of effects loops and I feel it’s worth exploring them so that you understand how they work. If your amp has an effects loop it’s going to be one or the other.

The Parallel Effects Loop

Amp's Effects Loop

The parallel effects loop is the less common design for effects loops but shows up enough to justify looking at.

This effects loop design mixes your amps dry or original signal, with the wet or “modified by effects” signal.

When your effects return to the amplifier, there is normally a control that allows you to mix the wet and dry signals together. This control allows you to have more of one and less of the other.

Mixing more of a dry signal with a bit of the wet signal can really give you a great sound with certain effects.

The only issue with the parallel effects loop and some effects is phase issues, but this can also turn out to be a great sound depending on what you are running.

Effects like EQ, tremolo, noise reduction don’t work as well in this type of effects loop unless set for 100 percent wet signal, but even then the dry signal can still be problematic.

Now i am not saying the parallel effects loop is a bad idea, it has its place!

But if your running your effects straight through the front of your amp, then the serial loop might be a better choice for you when getting started with the loop.

The Series Effects Loop

Amp's Effects Loop

With a serial effects loop, your entire signal is being changed by the effect you are running it through.

So when you send your signal from your amp to your effect pedal or processor, the amps pre-amp is running in series with the effect.

It is then sent back to the amp from your effects as one path from amp send to amp return.

The nice thing about a series effects loop is that you can essentially run any effect you want in the loop.

There is no dry signal running in parallel with the effects chain, its 100 percent wet when it comes back to the amp.

It is a very versatile effect loop design and is really all you will need for an effects loop.

Effects Loop Controls

Many amplifiers have effects loops that do not have any controls associated with it. You simply plug in your effects and adjust the master volume to taste.

There are other amps that include controls with their loops. These can be controls like

  • Send level control
  • Return level control
  • Foot switchable control
  • MIDI control

Send Level Control

Your send level control allows you to set the outgoing level to your pedals or processors.

Most effects pedals work with instrument level and can not handle a signal any hotter than that without clipping.

But some processors work with line level for optimal performance and some amps allow you to provide both signals with the send level control.

When setting up the control, if you have a pedal that is clipping and sounding dull, turn the level down until its resolved.

Return Level Control

Your return level control simply provides a signal back to the amp from your pedals or processors.

This level control is not seen very much as the master control in most amplifiers takes care of this for you.

But should you see it on an amplifier, it can assist with getting the right signal back to your amplifier.

Foot Control Or MIDI

Foot controlled or MIDI controlled effects loops on amplifiers allows you to turn the effects loop on or off.

This can be very handy if you are using MIDI control and don’t need to turn each effect off manually.

Turning the effects loop on or off can take care of all the effects at the same time and can be a handy feature.

4 cable method

Buffered Effects Loop

You may have heard this term before in your travels but not understood what it means. This is an important part of a high quality effects loop and really needs to be considered.

Most amplifiers on the market have buffered loops, but some techs might install a loop in an amp and not provide a buffered send level.

Buffering the signal sent to an effects pedal or processor is normally done by a vacuum tube, op amp or transistor.

Buffering is essentially conditioning the circuit to be able to provide the strongest signal possible without it being degraded when transferred to the effects. 

Without really getting into the science behind it, if the impedance and signal are not right, the quality of sound can be degraded badly.

Dull treble, weak signal and noise among other things can result.

But by creating a circuit that buffers the signal, you get the best quality sound when the signal is transferred between your equipment.

Amps With Effects Loops

If you’re looking for an amplifier with an effects loop, here are a few popular amps that you may want to look into!

Which Effects Go In The Loop

Here is a brief look at the effects you will want to run in your loop. The order in which to run them is not something we will look at here however as that comes to the desire of the player!

Time Based Effects

  • Delay
  • Reverb
  • Chorus
  • Flanger


  • Tremolo
  • Phase


  • EQ
  • Noise gate
  • Buffer
  • Volume


Some distortion pedals work better in the loop.

Learn To Use The Effects Loop

Spend some time learning your effects loop and what works best for your rig.

One of the things you might realize is that your sound is just so much better when using the loop.

Most players don’t know how to use it and just run effects into the front of the amp and miss out on its benefits.

Another thing that can benefit you is the 4 cable method.

This technique will allow you to find some amazing control in your rig. It might be just want you have been looking for in unlocking some amazing tone as well!

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5 thoughts on “How To Use An Effects Loop – Guide And Diagrams”

  1. Hey thanks so much for this article! I’m just now digging into the effects loop world. I was wondering… when you run a series effects loop, should I be setting my FX loop chain to 100% wet? (I’ve got reverb and delay only in that loop.) It seems strange to not have a ton of control on the ratio of dry signal to wet signal in this setup. Maybe I should stick a volume pedal and a clean boost in the FX chain to give myself a little more “control” over the amount of wet effects in this FX loop?
    Thanks in advance!! 🙂

    • Hi Sean,
      With a series FX Loop, your signal will normally be 100% wet depending on the configuration of your effects. If you are splitting the signal somewhere in your chain, then perhaps you may have more control over the amount of wet and dry signal being sent back to your amp. But normally a series FX Loop with effects daisy chained together will produce a wet signal being returned to your amp. A parallel loop will offer more control over the wet to dry ratio of your signal.

  2. Looking for some ideas/suggestions/tips on arranging time based FX with respect to their order for FX looping. As I’ve come to understand, its a “Season to Taste” endeavor, but perhaps there are some “Rules of Thumb” as to how a certain order would make a specific affect more pronounced, or not, or better blend if you will depending on where its placed in the chain. Appreciate your articles. Brian Pitman

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