Join the HC Newsletter.
Subscribe Now!
Sign In

Versatile four stage OTA based phaser


$185.00 MSRP, $185.00 "street"


By Phil O'Keefe



The EarthQuaker Devices Grand Orbiter Phase Machine (Fig. 1) is a four stage, all-analog phase shifter with a few additions that take it beyond the norm. Roughly based on both the vintage "orange box" Ross Phaser and DOD 490 Phasor pedals, it offers more control and sonic possibilities than either of those long-discontinued models.


A four-stage phaser typically uses four all-pass phase-shifting filters in series, with each changing the phase of the signal running through it. The sum of these filters determines how many "degrees" the signal can be phase-swept through, with a four-stage phaser providing 360 degrees of sweep - 90 degrees per stage. By adding a Low Frequency Oscillator (LFO ), the filters can be made to periodically sweep up and down through a range of audible frequencies. There is also a direct, "dry" signal path too, and the two signals, when combined, produce phase cancellations or "notches" that continuously sweep up and down through higher and lower frequency ranges, producing the characteristic "swooshing" phaser sound.



Grand Orbiter Fig1 copy.jpg


Figure 1: The EarthQuaker Devices Grand Orbiter Phase Machine





The Grand Orbiter is a solidly built pedal that measures 4.7" L x 3.7" W x 1.75" H. Earlier examples of the pedal used different looking knobs, and had a black on silver color scheme, but EarthQuaker Devices assures me that, cosmetics aside, there are no sonic differences. The labeling of the pedal is now silkscreened in dark red on a white background, and it's very easy to read, even under fairly low-light conditions. All patch points are located at the top of the pedal (Fig. 2), making it relatively easy to mount it very close to other pedals on your board, without the extra spacing that pedals with side-mounted jacks require. Input and output is on standard 1/4" jacks. The Grand Orbiter requires an external power supply (not included), and powering the pedal with a battery is not supported. The pedal runs on 9V DC, and any regulated 9V DC pedal power supply that has the standard "Boss style" 2.1mm center negative plug should work fine with it. I had zero issues running it with a One Spot, even with other pedals on the same daisy chain. Switching is true-bypass, and a cloth drawstring storage bag is included with the pedal.



Grand Orbiter Jacks Fig3 Copy.jpg


Figure 2: The Grand Orbiter's jacks and power plug are top-mounted





Unlike the vintage Ross and DOD units that it is roughly based on, the Grand Orbiter isn't your run of the mill, basic two-knob phaser. Consisting of four knobs and two 2-position toggle switches (Fig. 3), the controls on the Grand Orbiter are still quite simple and easy to understand, and yet they're much more capable than they may appear on the surface. This allows the pedal to cover a wide range of phaser sounds without being a pain in the neck to figure out, or to use. The Grand Orbiter's controls are also widely spaced, making it easy to adjust things - even with your toe.


Rate: The rate of the Grand Orbiter's LFO is controlled by the Rate knob. The pedal's very bright white LED indicator turns on when the pedal is active, and "pulses" at the same rate as the pedal's LFO sweep, increasing and decreasing in intensity in sync with the phase effect.


The first of the Grand Orbiter's two 2-position toggle switches is a Rate switch, and selects one of two time ranges for the LFO. In position 1, the overall range of the Rate knob is considerably slower. In fact, it can be downright glacial at the slowest settings. This is really cool for adding subtle movement to your sound, without making it too dramatic or overly obvious; it's kind of one of those "you may not notice it when it's on, but you'll definitely miss it when you turn it off" type of things. Exactly how slow? I clocked it in the 32 second range from peak to peak for a single LFO cycle with the Rate switch in position 1 and the Rate knob turned fully counter-clockwise. With the Rate switch in position 1, and with the fastest setting of the Rate knob dialed up, it provides about two cycles per second. Switching over to Rate 2 on the toggle switch provides a much faster range of settings. With the Rate knob in the fully counter-clockwise position, a single cycle takes about eight seconds to complete. How fast can it go? Faster than I could accurately count. My best estimate would be somewhere in the 6-8 cycles per second range, which is very fast indeed. It's plenty fast enough to allow the pedal to serve as an excellent source for way-out, sci-fi type noises, as well as machine gun and helicopter-esque sound effects.


Depth: The Depth knob controls the level of the phase shifted signal. You can think of this as a volume or blend control for the effected sound. The Depth knob has no effect on the "dry", unprocessed sound. Set low, it is capable of giving you nearly imperceptible levels of phase shift, or levels that are quite pronounced and slightly boosted relative to the level of the dry sound at much higher settings. At lower settings of the Depth knob, it's also possible to get mellower, pseudo two-stage phaser sounds from the Grand Orbiter.


Resonance: The Grand Orbiter's Resonance knob functions as a regeneration or "feedback" control. At higher settings it causes the phased signal to become more pronounced and chewy. Lower settings on the knob provide more subtle undulations. Again, I have to say how impressed I am by the wide rage of this control. As with the other knobs on the Grand Orbiter, it covers a broader range than I expected.


Sweep: The Sweep knob controls the phased signal's cutoff frequency. At lower settings on the knob the sound is thicker and meatier, and the range of the phaser's sweep affects the lower octaves of your guitar's signal. The sweep range extends much higher as you crank this control up. This control is fairly powerful, and considerable variation of the basic "range" of the frequency spectrum that is affected by the phaser can be achieved just by adjusting this knob. At high settings, especially when used with high amounts of Resonance, the sweep can accentuate any noise that might be present in your input signal. This isn't really the fault of the Grand Orbiter, which is a fairly quiet pedal; rather, it is due to the sweep extending into and accentuating the higher frequency ranges, where noise tends to be most audible.



Grand Orbiter Controls Fig3.jpg

Figure 3: The Grand Orbiter's controls are well labelled, and spaced ergonomically





The second toggle switch on the Grand Orbiter switches between Phase and Vibrato modes. When the Vibrato mode is selected, the "dry" signal path is cut off, leaving only the phase shifted signal. Depending on how you have the controls set, you can achieve both pitch vibrato and vibe-like sounds in this mode.


A word or two about the differences between a "vibe" and a "vibrato" pedal are in order here. The Grand Orbiter's "vibrato" mode can provide true pitch vibrato. With both the dry (unprocessed) and phase-shifted signals present, and the two sounds mixed together, phase cancellations occur. Without the dry signal to interact with, instead of phase shifting, you get vibrato. This can sound markedly different than a "Vibe" or Uni-Vibe® type pedal; most of which don't offer true pitch vibrato settings. "Vibe" pedals, which are also a form of "phase shifter", typically use photoresistor based circuits. Like the DOD and Ross phasers, the Grand Orbiter instead uses an operational transconductance amplifier (OTA) based design. The filters in a Uni-Vibe are typically offset and staggered, which gives that effect its characteristic "off-balance" thump and wobble. The sweep of the Grand Orbiter is generally more uniform, although you can get it to thump in a very vibe-like manner on some settings, especially in Vibrato mode with the Resonance control set fairly high.


To get started with the Grand Orbiter's vibrato mode, EarthQuaker recommends turning the Depth knob all the way up, the Resonance down low, and the Rate switch to position 2. Doing this results in a very credible, and very lush sounding pitch vibrato sound. As with the Phase mode, the Depth knob controls the level of the phase shifted signal. Since there is no other (dry) signal passing through the pedal when it is in Vibrato mode, the Depth knob essentially functions as a master level control, and turning it down to zero will kill all output, as if you had turned down a master volume knob. In Vibrato mode, the Sweep knob acts like a tone control, brightening or darkening the overall sound, while the Rate knob acts as you'd expect, and sets the rate of the vibrato's pitch fluctuations. The Rate switch also remains active in this mode, providing the same wide range of LFO times.




I've had a lot of fun with the Grand Orbiter. The overall sound of the pedal is very nice, and the range of usable sounds it can produce is far greater than any two or three knob phaser I've ever tried. It's considerably more versatile than most vibe pedals too. The pedal is also very well built, both inside and out. (Fig. 4)




Grand Orbiter Gutshot Fig4 Copy.jpg


Figure 4: The obligatory "gutshot", showing the Grand Orbiter's clean layout. Note the lack of a battery clip


The range of the controls is also noticeably broader than what you'll find on many other phasers, which further increases the Grand Orbiter's versatility. I really appreciate the musicality of the pedal, the subtlety of some of the sounds, as well as the the ability to dial up ultra-slow LFO speeds, but if you want things whacky and sounding like they're from outer space, it can easily launch you into orbit too. While it's not an inexpensive unit, the price tag seems quite reasonable, especially given the solid build, excellent sound quality, broad range of sounds, and the fact it can serve as a phaser, pitch vibrato, and even as a vibe substitute. If you're looking for a phaser that can cover a lot of ground, and sound great in the process, you owe it to yourself to check out the Grand Orbiter. True to its name, it's out of this world.




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.

No comments
Join the discussion...
Post Comment
More Cool Stuff
  Create ethereal, unusual reverb effects with phase reversal   by Cra...
Expert Reviews
Guitar accessories aren't always the sexiest products we get to review. Most are...
SPL Phonitor mini Starts Shipping The newest member in the SPL Phonitor family...
sign in
contact us
*Indicates required fields
Name *
Email Address *
Issue Type *
please wait