In the world of guitar pedals, Electro-Harmonix has a reputation for creating unique modern effects and solid reproductions of classic pedals. The Polyphonic Octave Generator ($698) is the company's modern take on the classic '60s analog octave pedal made famous by Jimi Hendrix. Octave pedals re-create an input signal an octave higher or lower in pitch, allowing guitarists to create thick, synthetic-sounding tones. Octave pedals aren't just for guitarists; Ike Turner was known for experimenting with them to create a suboctave harmony for his voice.
The Electro-Harmonix POG can generate polyphonic signals one octave below, one octave above, and two octaves above the input signal. In fact, for each higher octave, the POG offers two voices: one voice that is precisely the chosen interval, and a second detuned version of the generated octave. The unit also provides a variable Low Pass Filter (LPF) with three modes that help refine the unit's sound.
The POG is a large pedal; its brushed-aluminum case is about as tall as a normal guitar pedal, but it's slightly longer and more than twice as wide. The mono ¼-inch TS input and output jacks are on the back of the unit, as is the AC jack (the unit cannot be battery powered) and the 3-position LPF Modes switch. Eight sliders and the toggle button (or footswitch) are on top of the unit. The toggle button is placed at the bottom right away from the sliders, which guitarists will appreciate. I tested the POG by connecting it between my guitar (a Patrick Eggle Berlin Pro V) and my amp (a Soldano Avenger). I never accidentally stepped on the sliders while toggling the effect.
Slip Slidin' an Octave
The POG is straightforward to operate. The first slider on the left, situated farther from the next six sliders, is the Input slider, which adjusts the gain of the input signal before the A/D stage. The next slider controls the output volume for the Dry Output signal, and can be used as a dry/mix control. The Sub Octave slider adjusts the output level of the suboctave, which is one octave below (half the frequency of) the input signal.
Next, the +1 Octave slider adjusts the output volume of the voice that is generated one octave above (twice the frequency of) the input signal. The +1 Octave Detuned slider controls the output level of another voice, which is a modulated, detuned version of the +1 Octave signal. To the right of those two sliders are +2 Octave and +2 Octave Detuned sliders, respectively, offering output volume controls of the voice that is generated two octaves above (four times the frequency of) the input signal. The frequencies of the detuned octaves are modulated at a fixed rate above and below the input signal. You can use all four octave sliders simultaneously, which can generate thick and rich walls of sound.
The final slider to the right is the LP Filter slider, which controls the cutoff frequency of the lowpass filter. All of the generated octaves go through the lowpass filter. The dry signal bypasses the lowpass filter if the LPF Modes switch is in position 1, but in positions 2 and 3, the dry signal passes through the lowpass filter as well. The LPF Modes switch sets the Q to either 1 (modes 1 and 2) or 2 (mode 3). In actual use, I couldn't see a significant difference between any of those Q settings. (According to Electro-Harmonix, the slider ranges are significantly different, and the effect offers many distinct tonal possibilities, especially when recording.) A status LED on the top of the unit near the LPF switch indicates whether the POG is engaged. In Bypass mode, the input jack is connected directly to the output jack, bypassing the AD/DA stages.
All of these octaves and level sliders provide extensive creative control in blending your dry signal with as many as three additional octaves. The POG itself is not transparent; it seems to thin out any input signal to some degree. You can compensate for that by using the various sliders to thicken your signal without creating an audible effect. The included instruction sheet offers suggestions on achieving 12-string-guitar-like tones, a bass sound, and an organlike sound, but the most effective use of the pedal will come from experimenting on your own.
Although the POG is not the least expensive way to generate octaves, because of its polyphony and filter implementation, the unit offers a level of creative control lacking in most other octave pedals. Musicians looking for a modern pedal to use for experimenting with octave effects should definitely give the POG a look.
Overall Rating (1 through 5): 3
Electro-Harmonix/New Sensor Corporation