FIVE ANALOG GUITAR EFFECTS EMULATIONS

If you want analog sounds in a digital age, try these simple techniques

by Craig Anderton

Fancy signal processors aren’t always necessary to emulate some favorite guitar sounds and effects. In today’s digital world, a variety of programs and effects can be made to do your bidding. Want proof? Check out these five examples. For example...

VINTAGE WA-WA EFFECTS

Many people try to obtain a vintage wa sound simply by sweeping a highly resonant parametric EQ set to bandpass response. This isn’t possible because vintage analog wa pedals have steep response rolloffs that reduce both high and low frequencies, but there is a way to use modern parametric EQs to re-create this effect (Fig. 1).

1. Copy the guitar track so you have two “cloned” tracks set to the same level.
2. In track 1, insert a parametric EQ set to bandpass (peak/dip) mode with about 6dB gain and Q (resonance) of around 8.
3. Flip track 2 out of phase.
4. Sweep the EQ over a range of about 200Hz – 2.2kHz.

Fig. 1: The mixer channel on the left is going through a parametric stage of EQ. The channel on the right doesn’t go through an equalizer, but is flipped out of phase (the phase button is circled in red).

Throwing one track out of phase causes the high and low frequencies to cancel, so all you hear is the filtered midrange sound—just like a real wa-wa.

ADDING AMBIENT “AIR”

Recording guitar direct and be simple and produce a clean sound, but sometimes it’s too clean because there aren’t any mics to pick up the room reflections that give a sense of realism. To model these reflections, feed your guitar track through a multi-tap delay plug-in, or send it to at least two stereo buses with stereo delays where you can set independent delay times for the two channels.

Next, set the delay times for short, prime number delays (e.g., 3, 5, 7, 11, 13, 17, 19, and 23 milliseconds) to avoid resonant build-ups. Four delays is often all you need; I generally use 7, 11, 13, and 17ms, or 13, 17, 19, and 23 ms, depending on the desired room size (Fig. 2).

Fig. 2: Finding delay lines that can give short, precise delays isn’t that easy, but Native Instruments’ Guitar Rig—shown here using two splits, each with its own stereo delay—can do the job.

More delays provide a more complex ambience, but sometimes a simple ambience effect actually works better. If you want more “air,” try adding some feedback within the delay, but make sure it’s not enough to hear individual echoes. Experiment with the delay levels and pans, then mix the delayed sound in at a low level.

THE CLOSED-BACK TO OPEN-BACK CABINET TRANSFORMATION

With open-back cabinets, low-frequency waveforms exiting through the cabinet back partially cancel the low-frequency waveforms coming out the front. Emulate this effect by reducing bass somewhat; a low-frequency shelving filter works well, as does a high-pass filter.

OUT-OF-PHASE PICKUP EMULATION

Don’t have an out-of-phase switch? You can come close with a studio-type EQ (Fig. 3).

1. Select both pickups at the guitar itself, and feed its output into a mixer channel.
2. For the EQ, dial in a notch filter around 1,200Hz with a fairly broad Q (0.6 or so) and severe cut—around -15 to -18dB.
3. Use a high shelf to boost about 8dB starting at 2kHz, and a low shelf to cut by -18dB starting at 140Hz.
4. Tweak as needed for your particular guitar and pickups.
5. Boost the level—like a real out-of-phase switch, this thins out the sound.

Fig. 3: The Sonitus EQ set for a sound that emulates an out-of-phase sound with guitar pickups.

THE BIG BASS ROOM BUILD-UP

When a cabinet’s close to a wall, bass waves bouncing off the wall reinforce the waves coming out the cab’s front. This can produce a “rumble” due to walls and objects resonating, which EQ can’t imitate. For a killer rumble, split your guitar signal through an octave divider, then follow the octave divider with a lowpass EQ set to cut highs starting at 120Hz; this muddies the bass frequencies further. Then, mix the octave sound about -15dB below the main signal—just enough to give a “feel” of super-low bass.

Craig Anderton is Editor Emeritus of Harmony Central. He has played on, mixed, or produced over 20 major label releases (as well as mastered over a hundred tracks for various musicians), and written over a thousand articles for magazines like Guitar Player, Keyboard, Sound on Sound (UK), and Sound + Recording (Germany). He has also lectured on technology and the arts in 38 states, 10 countries, and three languages.