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Chorus pedal with extensive control and sound sculpting capabilities

$215.00 MSRP, $215 "street"



By Phil O'Keefe


EarthQuaker Devices are built by hand by tone-crazed Akronites in Ohio USA. At EarthQuaker Devices, they take a somewhat different approach than other pedal companies with many of their designs, and always seem to either have an interesting twist on the traditional concept for the pedal category, or add in some unexpected but welcome features that make their pedals unique and highly adaptive. Such is the case with the Sea Machine chorus pedal (or "Device" in EQD-speak) under review here. (Fig.1) 


Fig 1 EQD Sea Machine.JPG

Figure1: The Earthquaker Devices Sea Machine Chorus. Note the included drawstring cloth storage bag



Housed in an all metal box, and measuring 4.7" x 3.7" x 2.25" (including the knobs), the Sea Machine isn't the smallest chorus pedal on the market, but it's still reasonably compact, especially considering the number of controls it offers. The finish is a classy looking blue-grey metallic, with black painted over that - the lettering and labeling of the pedal is actually the unpainted areas not covered by the overlaid black paint, so that the metallic blue-grey shows through the black. Because of the high contrast between the two colors, readability of the labeling is excellent, even in fairly low light conditions. The knobs are well spaced, and everything is easy to adjust.

All jacks are top mounted, which further reduces the pedal's "footprint" - you don't have to allow for extra space between it and the adjoining pedal for jacks, cables and plugs, so you can position it much closer to other pedals on either side of it than you could if it had side mounted jacks. The Sea Machine is a mono in / mono out chorus. I would love to hear a full stereo version. Power is handled via a 2.1mm center negative "Boss style" power receptacle, which is also located at the top of the device. (Fig.2) The Sea Machine is adapter-powered only, and there is no provision for running it with a battery. Current draw is approximately 100mA.


Sea Machine IO.JPG

Figure 2: The Sea Machine's jacks are top mounted, making it easier to fit on a cramped pedalboard


The Sea Machine uses a hybrid circuit, but don't let that put you off - this is a very warm and lush sounding chorus pedal that can easily hold its own with all-analog designs in terms of creaminess and overall tone quality, and features far more expansive and comprehensive controls than most other chorus pedals - analog or digital.

The Sea Machine uses true-bypass switching. When the pedal is engaged, the analog dry signal goes through a transparent buffer to keep it robust and clean. Kicking the pedal on illuminates the incredibly bright blue-white LED. It's not bad at all when viewed from even a slight angle, but on a dark stage, when viewed on-axis (from directly above), it's almost painfully bright. The good news is that the LED pulses in time with the LFO, as controlled by the pedal's Rate knob, giving you a instant visual indication of the pedal's LFO speed.

As with all of the other EarthQuaker Devices pedals that I've seen, build quality and components are first-rate. The pedal is as clean inside as it is on the outside, although many users will never see the interior of the Sea Machine since there are no user adjustable controls inside, and no need to access the interior to change the battery since it doesn't use batteries. Still, to satisfy your curiosity, I'm including the obligatory "gut shot." (Fig.3)

Sea Machine interior.JPG

Figure 3: The Sea Machine doesn't use batteries, and there are no user-adjustable controls inside the neat and clean interior



The Sea Machine certainly has more knobs on it then a "basic chorus." Typically, a chorus will have two knobs - one for the rate, and another for width or depth. Even a casual glance at the Sea Machine tells you there's more than that available here. Let's take a look at each of the controls and what they do.


  • Rate: This controls the LFO speed.
  • Shape: This controls the modulation waveform. Turning this knob counter-clockwise gives you a soft triangle (almost sine) wave, and when cranking at full up, it's a square wave. This lets you go from very smooth to extremely choppy modulation at the twist of a knob.
  • Dimension: This is a rather interesting control that adds a degree of ambiance to your sound. With the knob all the way down, it has no real effect, but at low levels on the knob, the effect is somewhat similar to a short snapback delay. As you turn the knob up, it becomes more reverb-like in character. At extreme settings, the sound is more like a echoey resonant filter.
  • Intensity: This controls how hard the LFO modulates the delay time.
  • Animate: This knob controls the delay time and the amount of pitch shifting "sweep" - how far it swings sharp and flat. Lower settings offer a more traditional chorus type sound, while higher settings get far more seasick and crazy.
  • Depth: You can think of the Depth control as a blend knob - it adjusts the amount of modulated signal that gets mixed in with your dry signal.


With six knobs, it's a more complex chorus than most, but it's much easier to dial it in than it might seem on the surface. If you are a bit overwhelmed by the possibilities and don't know where to start, turn down everything except for the Rate and Depth controls and start from there. It will function just like a regular two knob chorus. Bring up the Intensity knob until you like what you're hearing, then experiment, one knob at a time, with the Dimension, Animate, and Shape controls until you have a better idea of how they affect the sound. Once you do, you can easily get lost in this pedal - more than once I found myself loosing track of time and experimenting for quite a while, coming up with one interesting sound after another.



There's a lot of headroom on tap with this pedal. In fact, EarthQuaker specifically recommends placing it after fuzz or overdrive pedals (and before signal boosters) for best results, and even when being hit hard by a high-output distortion pedal, the Sea Machine happily played along, with no complaints, no mush, and no signs of clipping. For even more headroom, you can always opt for running at 12V, but I never "needed" to, even when slamming the input pretty darned hard and running the pedal at 9V. Running at 12V had more of an effect on the sound of the pedal than on apparent headroom, with the higher voltage providing somewhat increased delay time, more modulation intensity, and more sparkle to the tone overall. Don't be tempted to try any higher voltages though - the Sea Machine tops out at 12V, and attempting to run it at anything higher than 12V will very likely damage the device.

My "wish it had" list is pretty short. About the only thing that really stands out is the lack of a stereo output, but even in mono, the Sea Machine is rich and full sounding, with wonderful sonic character and an inordinate amount of user control over the chorusing. Having the ability to change the waveform from soft triangle to square, and all points in between, provides a range of sounds that fixed waveform chorus pedals can't match. This isn't your dad's 80s era chorus. The ambiance added by the Dimension knob further separates the Sea Machine from other chorus pedals, and the Animate control can easily throw things over the top if you want to go there, or can provide more traditional chorus sounds at lower settings if that's what you're after.

EarthQuaker Devices has another winner on their hands with the Sea Machine. It's a first rate chorus with some nice extras added that definitely increase its flexibility, utility, and the range and types of sounds it can generate, and all that makes it well worth checking out the next time you're in the market for a new chorus pedal.



Phil\_OKeefe HC Bio Image.jpg

 Phil O'Keefe is a multi-instrumentalist, recording engineer / producer and the Associate Editor of Harmony Central. He has engineered, produced and performed on countless recording sessions in a diverse range of styles, with artists such as Alien Ant Farm, Jules Day, Voodoo Glow Skulls, John McGill, Michael Knott and Alexa's Wish. He is a former featured monthly columnist for EQ magazine, and his articles and product reviews have also appeared in Keyboard, Electronic Musician and Guitar Player magazines. 











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