Onboard Effects Loops and Switchers Explained

Guitar amps of yesteryear were straightforward when it came to effects pedals. Back in the ‘60s, musicians could just grab a wah pedal, fuzz or treble booster and run it directly into the front of an amp. Today most amps are equipped with an onboard effects loop that runs time-based and modulation effects between the preamp and the power amp, though this can confuse beginners or even seasoned players who have only run pedals straight into an amplifier.

Setting the Effects Loop Record Straight

When an amp is equipped with an effects loop, players need a general understanding of how and when to use it. To use an effects loop, run an instrument cable from the amp’s send jack to the input of the first pedal in the chain. Run another instrument cable from the output of the last pedal into the amp’s return jack. If you don't use the effects loop, it's a good practice to plug a cable into both the send and the return every month or so to make sure the contacts on the jacks stay clean.

Generally, time-based effects — like delay and reverb — and modulation effects — like chorus, phaser and flanger — are plugged into the effects loop. Think of it this way: if you run a delay before the distortion, you would get distorted delay, not delayed distortion.

Effects Loop of an Orange Rockerverb

For delayed distortion, use the effects loop after the preamp. Sure, back in the ‘80s, most analog delays sounded great straight into an overdriven Vox AC30 or Marshall JCM800. But those amps predated modern multi-effects units that have an abundance of sounds that would just be obscured by the front of a distorted amp. Running delays and reverbs through an effects loop provides a much cleaner, more transparent sound.

Now that last point is up for discussion because some modulation effects sound better before the preamp. It’s up to the player to decide which ones benefit from that arrangement.

  • A phaser or flanger will sound “whooshier” and airplane-like when placed in the effects loop after the preamp.
  • A chorus sounds more pitchy and bouncy.

Personally, I like modulation effects before the preamp because they sound smoother and creamier, great for both clean chords and distorted lead lines that really fatten up the sound. Try it both ways and figure out which one suits you!

True Bypass Loopers: Do You Need One?

If you have a large pedalboard and you’re sick of tap dancing all over the place to turn multiple pedals on and off for certain parts of a song, a true bypass looper could solve that problem. It could also take care of signal-chain issues. True bypass loopers feature send and return loops to add one or multiple pedals to a single loop. That can provide a convenient way of tackling the tap dancing problem if you use the same sound with the same pedals in different songs.

True bypass purists use loopers to put old and noisy effects in a loop to bypass them when off so they don’t bleed over into the signal chain. That also helps with older effects that don't have LEDs to indicate when they are on or bypassed. Like channels of an amp, that type of looper is run in front of an amp and used to control overdrive and distortion pedals. Also, the linear switching layout aids fast effect changes on the fly.

Modern Switchers

For those who like to tinker with complex effects signal routers, you can choose from several options. A more straightforward switcher, the Carl Martin Octa-Switch, features eight channels that correspond to eight loops. Assign the loops to each channel via a bank of DIP switches and an input to switch the channel or reverb on the amp. Players can insert the send and return jacks of the amp’s effects loop to incorporate those effects as well.

Boss ES-8 Effects Switching System

Other modern and more complex switching units include the GigRig G2 Switcher as well as the Boss ES‑8 Effects Switching System. Both have nearly limitless possibilities for effects combinations as well as MIDI capabilities to switch patches on any MIDI-capable device. If none of those options allow enough flexibility to control to control the setup, Bob Bradshaw of Custom Audio Electronics creates switching systems from the ground up based on an entire rig.

Effects loops and switching loopers are always popular and hotly debated topics on internet forums, but as an individual player, the decision rests with you. Experiment with the suggestions in this article to find your perfect setup.

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