Dave Hunter | 09.10.2008
In Part 1 of this Tone Tips mini-series on effects pedals we discussed stompboxes used in a chain between your guitar and the input of your amp, and that’s still the way the majority of traditional, one-effect pedal units are used. But some of you will have been thinking along the way, “What about my amp’s effects loop? Isn’t that the place to stick ’em?” In many cases, yes, but in other cases, no—which is to say, certain pedals work best plugged into the front end of an amp, even when you’ve got an effects loop built into it, while others will indeed thrive in yonder loop. Let’s investigate, and help get you wired for optimum sound.
Before you can figure out which effects to put where, you need to understand where an effects loop occurs in an amp’s circuit, and how it is intended to function. The majority of amps with effects loops, if not all of them, are modern-styled, high-gain amps, which often have footswitching to let you change between two or three channels for clean and lead sounds (sometimes with a “crunch” sound in between, in the three-channel amps). These amps seek to give you an all-in-one overdrive sound and eliminate the need for overdrive and distortion pedals, although you might still like to have your favorite OD or two in the rig to tap into different flavors of lead tone. With these high-gain preamp options at the front end of the amp, followed by individual or shared EQ stages, it makes sense to put the effects loop after all the up-front overdrive and tone shaping within the amp, but before the output stage, where the volume gets ramped up before hitting the speaker, and that’s just where amp makers put them. There are also some non-channel-switching amps that are made with effects loops, and on these the loops still go after the preamp and before the output stage. It’s just that you’re more likely to use some form of booster or overdrive pedal in the front of these amps to achieve your lead tones.
Now, refresh yourself on the “standard” effects order discussed in Part 1, and you begin to discern what should go where. Since overdrive, fuzz and distortion pedals usually want to go at the front of the signal chain—which is where the channel-switching amp automatically puts them—you naturally want to put modulation and delay effects such as chorus, echo and reverb in the effects loop, where they will affect the overdriven sound. Similarly, rack-mounted reverbs and delays want to be routed through the effects loop. Some vintage-style analog chorus, vibe, and phaser pedals might best do their thing for you if placed in front of the amp’s input (as discussed in Part 1 regarding placing these pedals in front of overdrive devices), and if you’re using overdrive, distortion, or fuzz pedals in addition to your amp’s own channel-switching clean/lead capabilities, those pedals go in front of the input, too. Also, some stand-alone “surf style” vintage tube reverb units perform best when routed between guitar and amp input.
Be aware that there are two main breeds of effects loop: series and parallel. The series loop is the simplest and operates as if you have snipped the wires inside the amp between the preamp and output stage and wired in a “send” jack at the front end and a “return” jack at the back end. In fact, that’s exactly what it is, using a switching jack to hard-wire the circuit back together when nothing is plugged into the loop. These loops send the entire signal out through whatever effects you plug into them. Parallel loops, on the other hand, include a bypass route and a send/return route, the two of which are usually balanced with a “mix” or “blend” control of some sort. These allow the player to decide how much signal is routed out through the effects in the loop, and how much bypasses the loop and goes straight to the output stage as a “dry” signal. Each has its benefits, and detractions. Certain effects might sound fullest when you route the entire signal through them, while in some cases doing so will dull or thin out your tone—in the case of effects units that deplete your unaffected, “dry” sound in some way or other—and routing part of it around the loop via a parallel loop’s mix control can help to keep it full and true. What works best for you is usually a matter of some experimentation.
Also, different effects loops sometimes put out different signal levels, and it’s important to check the users manuals of both amp and effects to ensure that the line levels of the outputs and inputs of each are compatible. Some parallel-loop amps and some rack effects likewise allow you to switch between two preset output or input levels (-10 dB or +4 dB, for example), or provide a “level” control of sorts that lets you set the desired level of the loop signal. Others—series effects loops in particular—give you an all-or-nothing signal. In the case of these, you sometimes need to work carefully with the effects placed in the loop to avoid overloading sensitive reverb and delay units. This applies to digital effects in particular, which will issue nasty digital clipping when hit too hard.
Before closing this installment, let’s briefly discuss the multi-FX units that have become popular with some players. Pros, tonehounds and pedal freaks aren’t usually big fans of these all-in-one units, and tend to be drawn more toward the depth and texture afforded by effects pedals that devote themselves to one sound at a time, but having a wide selection of selectable, footswitchable effect sounds on tap in one handy box is certainly a great boon to plenty of players. The simpler of these devices have routing functions that are just like big stompboxes, which is to say, just a straightforward input and output, with all the available sounds—filters, overdrive, chorus, echo, reverb—sandwiched in between. As such, they really need to go into the front-end input of your amp (although in some cases, and particularly if you’re going to use your amp’s lead sounds more than those of your multi-FX, saving the latter for its modulation and delay effects primarily, you might try it in an effects loop).
Some more sophisticated multi-FX floor units include their own effects loops, routed between the overdrive effects and the modulation and delay effects. This configuration is intended to let you place other favorite effects in a loop routed through the floor unit, but you can achieve great results by routing and effects loop-carrying amp in the multi-FX unit’s loop. Here’s how you do it: plug your guitar into the multi-FX unit’s input, route the loop “send” from the unit to your amp’s input, patch a cord from your amp’s effects loop’s “send” to the “return” of your multi-FX unit and, finally, connect the unit’s output to the “return” of your amp’s effects unit. This puts the multi-FX unit’s filter (sometimes including wah-wah), booster, and overdrive effects in the front end of your amp, and the modulation and delay effects in the amp’s effects loop, right where they all want to be.