Electro-Harmonix Pitch Fork - Polyphonic Pitch Shifter

Electro-Harmonix Pitch Fork - Polyphonic Pitch Shifter

The Pitch Fork transposes an instrument’s pitch over a +/- three octave range and features three modes which allow the pitch to be transposed up, down or both, simultaneously. The pitch shift amount can be set to a fixed interval or continuously varied by an expression pedal or control voltage. 
The controls are straightforward and intuitive. An 11-position Shift switch selects the maximum transposition interval ranging from D (Detune), a shift of 17 cents, through Minor 2nd, Major 2nd, Major 3rd, Perfect 4th, Perfect 5th, Major 6th, Minor 7th, 1 Octave, 2 Octaves and 3 Octaves. A three position toggle switch controls whether the pitch is transposed up, down or both. In Dual mode, two pitch-shifted signals are output. One follows the shift knob as if in the Up position while the other creates a harmony. Dual Mode settings include M3 up + P5 up, P5 up + 1 Oct down, 1 Oct up + 1 Oct down and many others. A Blend knob controls the mix of the dry signal and the effected signal, and an EXP jack enables the player to control pitch and glissando with an expression pedal.
The Latch button selects Latch or Momentary mode which affects how the footswitch and EXP input behave. In Latch mode, the footswitch toggles between effect on and buffered bypass each time it’s pressed and the EXP input continuously varies pitch. In Momentary mode the effect is only on while the footswitch is depressed and when it is released the Pitch Fork goes into bypass. 
In Latch mode the EXP input controls pitch shift amount, ranging from unity to the interval set by the Shift knob, and pitch varies continuously throughout the expression pedal’s range. In Momentary mode the EXP input controls glissando rate for the Pitch Fork’s footswitch. When the bypass footswitch is pressed, the Pitch Fork jumps from bypass to the interval set by the Shift knob. The amount of time it takes to reach that new note is the glissando rate. When the footswitch is released the pitch will return to unity at the same rate. That glissando time can vary between 4 milliseconds to two seconds depending on the heel/toe position of the expression pedal. The default glissando rate is 60 milliseconds when nothing is plugged into the EXP input.
The Pitch Fork comes equipped with an EHX 9.6DC-200mA power supply and also runs on a 9Volt battery.

Quick Specs

GETTING STARTED
Connect the output plug of the supplied power adaptor to the 9V power jack. Plug your instrument into the INPUT jack; connect your amp to the OUTPUT jack. Set the toggle switch to UP arrow and press the LATCH button so it is down. Turn BLEND fully clockwise and set SHIFT to 1, as in 1 octave up. Press the footswitch until the LED lights up. You will hear all your notes shifted up 1 octave. Connect an optional expression pedal to continuously vary the pitch from unity up to 1 octave.

Press the LATCH button so it is up. The footswitch now has a momentary action: when pressed the effect activates and pitch is shifted; when released, the effect is bypassed. Connect an expression pedal to control glissando rate of the momentary footswitch. If the EXP jack is vacant, pitch will change at the default glissando rate of 60ms (this is user adjustable). 

BLEND KNOB
The BLEND knob mixes between the untreated, analog dry signal and the effected signal. At BLEND’s full clockwise position, the output is 100% wet.

SHIFT KNOB
The SHIFT knob selects the maximum interval of chromatic transposition. The chart below shows how the pitch will be shifted relative to the original pitch.

MODE TOGGLE SWITCH
The MODE toggle switch selects whether the pitch is shifted up, down or both simultaneously relative to the root. Dual mode outputs two pitch-shifted signals. One of the shifted signals follows the SHIFT knob as if in UP mode. The other shifted signal creates a musically useful harmony according to the SHIFT knob setting. 

DUAL mode SHIFT knob Settings:

LATCH BUTTON
The LATCH button selects Latch or Momentary mode. This affects how the footswitch and EXP jack input behave. When the LATCH button is down, Latch mode is enabled. The footswitch toggles between effect and bypass each time you press and release the footswitch; the EXP input continuously varies pitch. When the LATCH button is in the up position, Momentary mode is selected. The effect is only on while the footswitch is held down, otherwise the Pitch Fork is bypassed; the EXP input varies the glissando rate of the momentary footswitch.

BYPASS FOOTSWITCH & STATUS LED
The footswitch toggles between effect on and buffered bypass. In Latch mode, each press and release of the footswitch toggles between effect and bypass modes. In Momentary mode, when the footswitch is held down, the effect is on, when the footswitch is released, the Pitch Fork enters bypass. The status LED lights when in Effect mode. 
EXP JACK
EXPression input jack accepts a TRS expression pedal connector or a Tip-Sleeve 0-5V control voltage input. The expression pedal should ideally use a 10k potentiometer with linear rather than audio taper. It must have the wiper connected to TIP and toe-down connected to RING. Pedals made by some manufacturers do not conform to this convention, and would need a special cable to swap RING and TIP. Some suggested Expression Pedals: EHX Expression Pedal, M-Audio® EX-P, Moog® EP-2 & EP-3, Roland® EV-5 or Boss® FV-500L.

LATCH MODE - the Expression/CV input controls pitch shift amount, ranging from unity, or no pitch shift, in the heel position to the interval set by the SHIFT knob for the toe position. Pitch varies continuously from heel to toe in all settings.

MOMENTARY MODE - the Expression/CV input controls glissando rate for the Pitch Fork’s footswitch. When the bypass footswitch is pressed, the Pitch Fork jumps from bypass to the pitch shift interval set by the SHIFT knob. The amount of time it takes to reach the SHIFT knob’s interval setting is the glissando rate. When the footswitch is released, pitch will return to unity by the same rate. When your expression pedal is heel-down the rate is 4ms, in toe-down the rate is 2sec. When no device is plugged into the EXP input the default glissando rate is 60ms.

SAVING NEW GLISSANDO RATE SETTING FOR PITCH FORK FOOTSWITCH
1) Set LATCH mode button to the Momentary or up position.
2) Connect expression pedal or CV device to EXP jack.
3) Press and release Pitch Fork’s footswitch while adjusting expression pedal or CV device until you hear desired glissando rate. Leave external device in current setting.
4) Press and hold down the Pitch Fork’s footswitch.
5) Press LATCH button so it changes to Latch mode. LED flashes to confirm. 
6) Release the footswitch.
7) The new glissando rate is now saved. Remove plug inserted into EXP jack, change back to Momentary mode and use footswitch to confirm new rate.

RESTORING FACTORY DEFAULT FOR GLISSANDO RATE
1) Make sure nothing is plugged into EXP jack.
2) Set LATCH button to Latch mode, the down position.
3) Press footswitch so that Pitch Fork is in Bypass.
4) Press and hold down the Pitch Fork’s footswitch. 
5) Press LATCH button so it changes to Momentary mode. LED flashes to confirm.
6) Release the footswitch.

OUTPUT JACK
Outputs the wet/dry mix set by the BLEND knob. 

CHANGING BETWEEN LATCH AND MOMENTARY WHEN EXPRESSION PEDAL IS CONNECTED
When in Latch mode and you switch to Momentary mode the expression pedal position is ignored. The stored glissando rate will take precedence until the expression pedal is moved from current position.

LED ON STARTUP
The LED will blink 4 times then hold on the 5th if in latch mode or toggle off if in momentary. This happens when AC power is applied or you plug into the input jack with a fresh battery installed. If battery power is too low, the LED blinks dimly, every other second. 

CHANGING THE BATTERY
To change the 9-volt battery, you must remove the 4 screws on the bottom of the Pitch Fork. Once the screws are removed, you can take off the bottom plate and change the battery. Please do not touch the circuit board while the bottom plate is off or you risk damaging a component. To extend battery life, disconnect the INPUT jack when the Pitch Fork is not in use.

NOTES AND SPECIFICATIONS
• PITCH FORK has high quality buffered bypass.
• Input impedance is 2.2MOhm.
• Output impedance is 680Ohm.
• Current draw of the PITCH FORK is 30mA.