You don’t see many bass amps with built-in effects. We get to pick between active or passive and that’s it.  And I’m not talking corny DSP presets or a one-button compressor – I mean the old-school effects guitarists get from classy amps like Magnatone, Fender, et cetera. Effects that get their own input. Like vibrato. Like the Aqueduct vibrato.

With eight modes and convenient Flexi-Switch® Technology which allows the choice between latching and/or momentary switching simply by pressing and holding the footswitch, the Aqueduct vibrato expands the musical possibilities of frequency modulation galaxies beyond “normal or vibrato.”

Aqueduct’s Flexi-Switch® Technology makes it easy to pop the vibrato effect in for a note or phrase without throwing your singer off pitch. And with Sine, Triangle, Ramp, Square, Random, Envelope-controlled Depth, Envelope-controlled Rate, and Envelope-controlled Pitch modes to choose from, there’s plenty for bassists to love about the Aqueduct, from vocal fretless melodies (which I’ll let Juan Alderete demonstrate) to disgusting randomized pitch bends (which are a little more my speed).

Vibrato, that’s what Fender amps have, right?

Wrong. There’s a lot of confusion around this, so let’s set the record straight: though Fender amps are labeled “Vibrato,” the effect the vibrato channel produces is actually tremolo, or amplitude modulation. We hear this as a change in volume. True vibrato, like the kind you get when you bend a string back and forth in tempo, is a fluctuation in wavelength, which our ears hear as a change in pitch. So how did this happen?

In 1954, when Fender placed ads for a new space-age guitar called the Stratocaster, the headline mentioned something called “Tremolo Action.” This, of course, was in reference to their new floating bridge mechanism which allows all six strings to bend at once and return to pitch. The key word in that last sentence is “pitch.” One can only speculate as to the Fender marketing department’s logic for going with “Tremolo Action” as opposed to “Vibrato Action,” but the terms “tremolo” and “vibrato” have been used interchangeably ever since.

But what has EarthQuaker Devices ever done for us?

Well, for starters, we get all your Monty Python jokes. Beyond that, we designed the Aqueduct vibrato to be simple enough that you could treat it as a replacement for built-in amp vibrato, but deep enough to inspire new musical ideas, and if you really crank it, weird enough to be down for whatever.

The first four modes – Sine, Triangle, Ramp, and Square ­– should sound plenty familiar to anyone who’s ever messed around with a modulation pedal and/or synthesizer. In these modes, an LFO modulates the pitch of your signal in the shape of whichever waveform you’ve chosen. Sine is smooth and produces the most amp-like vibrato, Triangle has a sharper rise and fall with a chorus-like quality, Ramp has a synthesizer-like quality with a sharp rise followed by a dramatic sustain and release, and Square produces a trill effect as it instantly jumps between notes like doing hammer-ons and pull-offs with a bionic arm.

Random mode – which doesn’t adhere to any standard waveshape because then it wouldn’t be random anymore – takes the input signal and slurs it into a seasick microtonal wash that when dialed back, gives you the heartwarming nostalgia of a well-loved (if slightly warped) vinyl record, or if you really crank it, sounds like the end of the world.

The remaining three Envelope-controlled modes offer touch-sensitive amplitude-based control of the Rate, Depth, or Pitch. In the Env R setting, the Aqueduct goes faster the harder you play, and the vibrato Rate will slowly wind down as each note decays. Env D lets you set the Depth with your pick attack. Env P, which we like to call “the My Bloody Valentine setting,” produces tactile pitch bends that replicate whammy bar bends. No, really – that’s what it says in the manual.

How’s it sound?

Aqueduct’s Sine mode delivers the same classic amp-like vibrato that you’re probably already familiar with and gives fretless melody lines a human vocal quality that blurs the line between player and instrument. I’ll let Juan Alderete at Pedals And Effects explain…once he gets off the phone with Nick Reinhart:

Now it’s my turn. In these examples, I’m playing an Electrical Guitar Company Series One bass through the Aqueduct into a Tronographic Rusty Box preamp and a Tech 21 SansAmp RBI. I’m going direct from the SansAmp into a Universal Audio Apollo interface running the Unison Neve Preamp plugin into Pro Tools. I’m using a Massey L2007 limiter plug-in on the master fader to bring things up to a normal listening volume, but there is no other post-processing happening.

Example 1

In this clip, the Aqueduct’s Triangle waveform creates a wobbly see-saw effect that nicely compliments a rhythmic double-stop figure.

Example 2

Here the Aqueduct is set to random mode to add those disgusting randomized pitch bends I was talking about earlier to a tapped harmonic riff.

 Example 3

Set to Sine mode, the Aqueduct adds classic, amp-like vibrato to a simple rock bassline.

Aaron Rogers does Copywriting & PR at EarthQuaker Devices and plays the bass guitar in Ultrasphinx.