A Simple Acoustic Guitar Effects Loop Setup

Ask around or read up on using effects on an acoustic guitar and you’ll probably find as many different opinions as people you ask or articles you read. My intent is not to sway you from your opinions on the issue, but rather to take a look at the goals I had for my live acoustic guitar rig, what I used to get there and how I set it up. If you have a different experience, or other configurations that have worked for you, we’d love to hear about them.

Drop us a note in the comments at the end of this post.

The acoustic guitar purists are probably wondering, “Why would you even consider corrupting the purity of the acoustic guitar?“

That’s a fair question, because one of the perennial problems of amplifying an acoustic guitar is trying to maintain those qualities of sustain and resonance that occur naturally in an acoustic instrument, when it’s amplified.

My Acoustic Setup

I play a Taylor acoustic with the Expression pick-up system (ES-2) through a church sound system for worship. I identified a couple of things I wanted to change in my setup to try to achieve some of that ‘natural’ sound when my guitar was amplified. Here’s what has worked for me.

Maintaining a Balanced Signal

One of the great features of the Taylor Expression system is that the output from the guitar is balanced.  In simple terms, this means that two conductors are used for the signal instead of one. By inverting the signal in the two conductors, outside noise and interference can be cancelled out allowing much longer cable runs without signal degradation.

This is great unless you want to introduce anything else into the signal chain before plugging into your snake or mixer.

I wanted to incorporate a tuner into my setup that would allow me to mute my guitar and tune, as well as introduce several other helpful guitar pedals without losing the balanced quality of my Taylor’s output.

One of the issues I noticed when playing through the sound system at my church, is the guitar lost some of the ‘live’ or ‘resonant’ qualities that make an acoustic guitar sound good. While Taylor’s Expression is an excellent system, it doesn’t fully capture the resonance and sustain of the acoustic’s interior. This led me to work towards ‘re-introducing’ or recreating some of those qualities with sparing use of some basic effects.

Anyone who has played for a while or listened to others play begins to develop a sense of what they want their instrument to sound like. In some ways this can be the hard part- in today’s market there are almost infinite options for shaping and changing tone. Therefore, having that ‘sound’ you are after in your ear is at least half the battle, then it becomes an issue of experimenting and finding the right ‘tools’ for your sound.

This is what has worked for me.

Setting Up the Signal Chain

The first piece of gear I added was the Taylor K4 equalizer. 

Built by legendary audio engineer and designer Rupert Neve, this pre-amp and equalizer was conceived in conjunction with Taylor to work with the Expression system as a pre-amp, multi-band EQ and DI unit all in one slick package. These features add another level of tone control to the already capable Taylor Expression system.

The other feature that caught my attention was the inclusion of an effects loop that allowed separate effects to be ‘inserted’ into the signal path without losing the balanced output from the Expression system and the K4.

The K4 then became the ‘hub’ of my acoustic rig.

The first ‘external’ item I wanted in my signal chain was a Boss TU-3 Tuner, this rugged ‘stomp box’ style tuner provides accurate tuning and muting to allow for plugging/unplugging of your guitar or making other changes and adjustments-without the loud crackling and popping that are sure to make your fellow musicians cringe and bring down the ire of the sound engineers.

While I am only using the basic chromatic tuning functionality for my guitar in standard tuning, the TU-3 provides several other modes including bass and guitar specific modes that identify by string number instead of pitch; as well as a ‘semi-tone’ mode for alternate tunings.

The next item is a Boss CS-3 Compressor/Sustainer.

Compression is simply reducing the volume of loud sounds and increasing the volume of quieter sounds, thus ‘compressing’ the dynamic range of a sound or signal. This allows it to be amplified more to better hear the nuances of quiet elements in the lower part of the dynamic range without making the louder sounds too loud.

In the case of the acoustic guitar, a little compression allows some of those ‘nuance’ sounds to be heard without the percussiveness of the strumming getting overpowering. The CS-3 adds back a touch of that sustain that I hear when I'm playing unplugged to my amplified sound.

The Attack and Sustain controls are important because they control how quickly the compression takes affect and how much additional gain is added to the signal once it's compressed.

The next item is a Boss RV-6 Reverb. 

Reverb is the reflection that occurs naturally when sound bounces off of surfaces like the inside of an acoustic guitar or the walls in a room-even after the original source has stopped creating echoes that usually decrease in amplitude or strength until they die away.

Historically, this effect has been recreated by playing sound through steel plates or springs, but the RV-6 uses digital processing to mimic the reverberations of different sizes and shapes of rooms. (I’m using the “Room” mode of the RV-6, which is probably the least dramatic and most natural sounding setting). The Time control allows you to set how long the reverberations last.

This is a versatile pedal with seven additional reverb modes, including recreations of the classic plate and spring reverbs.

These four processors are the major pieces between my acoustic guitar and mixer, but how they are connected and how they work together is important.

I start with a Spectraflex TRS cable from my guitar to the K4. This is three conductor cables instead of two like a typical instrument cable- again helping to maintain the integrity of that balanced signal.

The K4 will accept both an XLR and a TRS input, but the K4 manual recommends using the TRS (as it’s optimized for the higher gain levels of the active Expression system). Next I feed the input of the Boss TU-3 from the effects send on the K4, then from the tuner to the Boss CS-3 Compressor/Sustainer, through the Boss RV-6 and back to the effects return on the K4. One of many likeable features on the K4 is the ability to choose whether the effects loop is before or after the K4's Equalizer section.

Finally, I use a TRS to XLR cable to take the output from the K4 and send it to the mixer.

A couple notes on powering effects

One of the biggest sources of noise in our instrument’s signal chains is poorly isolated power supplies.

All of the equipment in my acoustic rig is capable of running on battery power. 

Powering your effects with battery can be cumbersome (having to keep fresh batteries in your gear), but it is the optimal way to be sure you are not introducing outside noise into your signal.

For a more permanent approach consider something like the ISO-5 from Voodoo Lab.

This acoustic rig has helped me achieve a more natural sounding acoustic signal in our PA sound system at church.

The Taylor K4 is a powerful tool with extensive equalization and tone-shaping capabilities even when making slight boost or cut adjustments. Similarly, the Boss CS-3 and Boss RV-6 are robust compressor and reverb effects, and as stated earlier, I am only using a touch of their capability to get the sound I am looking for.

It doesn’t take much to get extra control and variety in your acoustic guitar signal. Take your time, add components and make adjustments incrementally. Remember, you get what you pay for so invest in quality gear and learn to use what you have to the best affect.

Your Questions and Ideas

Have questions about this setup or the gear I used? Maybe you want to share how you use effects in your live acoustic rig or the reasons why you don’t.

Either way, drop it in the comments section below.