Review: Earthquaker Devices Space Spiral Modulated Delay

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The Space Spiral Modulated Delay Device from Earthquaker Devices is at once lush, and almost pristinely transparent. This unit is seasoned with analog flavor, and fortified with reliable digital technology. The Space Spiral fills the rather large gap that exists between experimentally-minded delay units, and reliable-yet-sometimes-too plain digital delays. All of the controls on the Space Spiral are intuitive, and like any self-respecting delay pedal, it has the capacity to self-oscillate in some useful and fun ways. Overall, this is a fine offering that is useful from the perspective of live performance as well as from a compositional standpoint; which is to say that this pedal will do well on the stage as well as in the studio. Let’s take a look at some of the features of the Space Spiral.


First off, the two horizontal rows of knobs correspond to the two different sections that make up the circuitry of this pedal. The top row of knobs controls the fundamental parameters of the delay itself (Time, Repeats, Mix), while the bottom row provides knobs for dialing in how the delayed signal is modulated. More conventional delay pedals, like the MXR Carbon Copy, also provide the option to modulate your delayed signal, but typically this option is something that can either be turned on or turned off, without any control over the sound of the modulation. The Space Spiral puts control over each parameter of the modulation in your hands. This is endlessly useful if you are someone who tends to keep the “mod” function of their delay pedal engaged, but would like to have more control over the modulation. 

Time: controls the total delay time. This pedal features a respectable delay range of 30 ms to 600 ms. Turn the knob to the left for less delay, and to the right for more delay.

Repeats: sets the amount of repeats that the pedal produces. With this knob turned fully down, the Space Spiral produces a single, clean repeat. When this knob is maxed out, not only will the pedal provide endless repeats, but it will also self-oscillate. In fact, once the Repeats knob is turned anywhere past the 3:00 position, the pedal will begin to self-oscillate endlessly until the knob is brought back down to a setting lower than the 3:00 position. This can be a useful effect when creating ambient soundscapes, or relentless noise textures. Once engaged, the self-oscillation will remain in effect even when the pedal is switched off. This is a nice feature for live situations, as it can assist with smooth musical transitions, by providing a lingering pad of sound. It is also a nice safeguard for those of you who do tend to play with lots of pedals and who rely on cascading effects to create your set, as it insures that your shoegaze/ambient/noise set won’t be cut short by accidentally stepping on the delay pedal. Conversely, if you are looking for a delay pedal whose signal can be immediately muted by bypassing it, you will want to look elsewhere, or simply place the Space Spiral in a switchable stage of your rig.

Mix: allows you to control how much delay (wet) signal is blended with your incoming (dry) signal. Turn the knob down for less, and up for more. Note that even with this knob at its fullest position, the Space Spiral will never completely get rid of your dry signal, so with this pedal set to its wettest setting you will still be able to hear some degree of your original attack.

Depth: allows you to control the degree to which the pitch of your affected signal is shifted. Turn the knob down for less, and up for more. Set to any position below the noon (halfway) point, this control provides a full spectrum of relatively subtle modulation flavors. Turn the depth knob past noon, however, for some very noticeable pitch bending effects. In fact, it is safe to say that once you cross the halfway point of this knob’s rotation, you have left behind shimmering subtlety and ventured forth into the dimension of pitch shifting.

Shape: enables you to change the shape of the modulating waveform, from a triangle wave at the leftmost position, to a square wave at the rightmost position. The square wave provides synthy textures, while the triangle wave is a bit smoother and more traditional sounding (assuming you are playing a stringed instrument). 

Rate: controls the frequency of the modulating waveform, or more simply put, the speed of the modulation effect. Turn this knob down to slow the wave’s rate, and turn it up to increase its speed. Again, past the noon position things start to get crazy. Particularly when the other knobs on the modulation row are set past noon as well, this pedal starts to get spacey and cosmic in all the right ways.

Bypass: the bypass switch on this pedal is a little different than what you might be used to. Thanks to something called Flexi-Switch Technology, this pedal’s switch is at once latching and non-latching. For latching use, simply click the switch once to engage or disengage the pedal. For non-latching applications, click and hold the switch to engage the pedal for as long as the switch remains depressed; once you take your foot or hand off of the switch, the pedal will go back to being bypassed. 

Spectrographic Analysis

Telecaster Style Guitar [Maple Fingerboard, Dimarzio D-Activator Humbucker (bridge position)] – Cable – Scarlett 2i2 Interface – MacBook Pro 15” 2012 – Logic Pro X

Powered by a grounded Voodoo Labs Pedal Power unit via 9V input.

No pedal in signal path


Space Spiral Delay bypassed, placed between Guitar and Interface

Not much signal loss or frequency gouging. Basically what you would expect from a boutique pedal.


Space Spiral Delay ON [Time: Noon; Repeats: Noon; Mix: Full; Depth: Full; Shape: 0; Rate: Noon]
Here you can see the effect that the Shape control has on the signal. The slight waviness is caused by the imposition of the modulation circuit on the instrument signal.


Space Spiral Delay ON [Time: Noon; Repeats: Noon; Mix: Full; Depth: Full; Shape: Noon; Rate: Noon]
With the Shape control halfway between triangle and square, you can see that the modulation is slightly more jagged.


Space Spiral Delay ON [Time: Noon; Repeats: Noon; Mix: Full; Depth: Full; Shape: Full; Rate: Noon]
Here the Shape control is maxed out, meaning that it is fully imposing the square wave signal. Notice the angularity of the signal.



If you enjoy modulated delay, but want something that gives you more control over the modulation effect than a Carbon Copy, or even a Memory Man, then The Earthquaker Devices Space Spiral Modulated Delay is worth your time. Despite being advertised as something of a low-fi throwback, this pedal’s clarity, tweakability, and low noise floor, all give it a surprisingly hi-fi feel. Perhaps a good way to think about the overall sound of this pedal is as a hi-fi take on a low-fi sound. Check it out for yourself.

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True Bypass: No
Battery Cavity: Yes
DC in: Yes (power supply sold separately)
Input(s): 1 x 1/4”
Output(s): 1 x 1/4”
1 M Ohm Input Impedance
<1K Ohm Output Impedance


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