Slammi Plus Instructions

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Polyphonic Pitch-Shifter/Harmony Pedal

Thank you for your purchase of the Electro-Harmonix Slammi Plus. The Slammi Plus polyphonically transposes the pitch of your instrument by various selectable intervals over a +/-3 octave range. In addition to standard musical intervals, you can also create a rich detune effect in which the harmonies are only slightly set apart. You can set the pitch-bend upwards, downwards, or even up and down at the same time, and then blend in your dry sound to create pitch-shifted harmonies. Switch to the cross-fade (X-FADE) mode to sweep between the dry signal and the fixed transposed pitch. Then use the BLEND knob to create the perfect mix between the dry and transposed notes. Spanning a range from conventional sounding whammy bar effects to otherworldly harmonically pitch-shifted bends, the depth and flexibility of the Slammi Plus will expand your sonic arsenal.

• The Slammi Plus utilizes a high quality, buffered bypass.
• Input Impedance: 2M
• Nominal Output Impedance: 750
• Current draw: 24mA

Connect your instrument to the INPUT jack and connect your amplifier to the OUTPUT jack. Toggle between buffered bypass and effect mode by firmly pushing the Slammi Plus pedal downward, in the toe direction, until you hear/feel the footswitch click. The Slammi Plus does not provide a visual indication that it is in either effect or bypass mode or that it is powered up. The Slammi Plus always powers up in bypass mode.

While in effect mode, rock your foot back and forth on the pedal to achieve various pitch-bend or cross-fade effects, depending on the setting of the knobs and switches. Refer to the bottom of the pedal for a quick printed reference to the function of each knob and switch, or see CONTROLS and CONNECTIONS on the next page for complete details. The knob and switch settings are highly dependent on each other, so take your time to learn how they interact.

Besides sweeping the pedal continuously, you can use the Slammi Plus to create pleasing fixed settings at certain spots along the pedal’s sweep. Listen to the pitch intervals or cross-fade mixes as you rock the pedal. When you hit just the right spot, carefully remove your foot from the pedal so that the sound remains fixed.

SHIFT Knob Rotary Switch The 11-position SHIFT switch selects the maximum bend setting or the interval of chromatic transposition. The table below details the pitch effect relative to the original pitch.

Note: “Detune” uses a slight interval to create a detune effect that is close to a chorus or doubling effect.

Flip the PEDAL switch to choose the function of the foot pedal: select either PITCH or X-FADE mode.

In PITCH mode: the foot pedal bends the pitch of your notes. The toe position yields maximum pitch bend, while the heel position’s pitch bend is set by the PITCH MIX knob.

In X-FADE mode: the foot pedal crossfades from your dry signal to the transposed signal at an interval set by the SHIFT knob. The cross-fade effect will vary depending on the DIR toggle switch setting:
• DIR UP () or DOWN (): the dry signal is in the heel, and the pitch shift effect is in the toe.
• DIR DUAL: the heel pitch is set by PITCH MIX knob (ranging from -1 Octave to +1 Octave), and the toe’s upward pitch is set by SHIFT knob.

DIR (direction) Toggle Switch The DIR switch selects whether pitch is shifted up (), down (), or both simultaneously (DUAL).

The DUAL setting outputs two pitch-shifted signals. The first transposed signal follows the SHIFT knob as if in UP mode. The second transposed signal depends on whether the PEDAL switch is set to PITCH or X-Fade:

1. When PEDAL is set to PITCH mode, the secondary shifted signal bends at the same rate as the primary signal—usually in the opposite direction, but not always. The secondary signal maxes out at a musically useful harmony that varies by the interval set with the SHIFT knob. This table lists the DUAL mode SHIFT knob settings with PEDAL set to PITCH mode:

2. When PEDAL is set to X-FADE, the secondary shifted signal is set by the PITCH MIX knob and does not bend. The volume of the secondary signal decreases by sweeping the pedal from heel to toe.

The function of the PITCH MIX knob varies depending on how you set the PEDAL and DIR toggle switches:

PEDAL Switch Set to PITCH (Pitch-bending Mode)
DIR toggle switch set UP or DOWN: the PITCH MIX knob sets the heel position’s transposition setting. The transposition range varies up or down in half-steps from the dry signal in the CCW position to the SHIFT knob’s setting in the CW position.
DIR toggle switch set to DUAL: the PITCH MIX knob varies the volume mix between the main shifted note and the secondary shifted note. Thus you can fine tune the mix between the transposed notes so that, for example, your downward pitch is louder than the upward pitch.
PEDAL SET TO X-FADE (Crossfade Mode)
DIR toggle switch set to DUAL: the PITCH MIX knob sets the heel position’s transposition setting in half-steps with a range from +1 Octave to -1 Octave.
DIR toggle switch set UP or DOWN: the PITCH MIX knob has no function.

BLEND Knob Adjusts the output mix between 100% dry (fully CCW) and 100% wet (fully CW).

INPUT/OUTPUT ¼” Jacks Connect audio to and from the Slammi Plus.

Internal Battery Plug a cable into the INPUT jack to activate power from the internal 9V battery. Unplug the input cable to avoid running down the battery when the unit is not in use. If an AC Adapter is used, the Slammi Plus will be powered up as long as the AC Adapter is plugged in. The pedal’s battery may be left in or taken out when the AC Adapter is in use.

Changing the Battery
1. We recommend the use of 9V alkaline batteries.
2. Locate the battery door on the underside of the pedal.
3. Push the tab of the battery door towards OPEN to unlock the door; pull the door up until it locks into its open position.
4. Connect your new 9V battery to the wired battery connector.
5. Insert/slide the 9V battery into the battery holder compartment. Push the battery door down and firmly snap it closed.

External 9VDC Power The power jack (marked 9V) is located next to the OUTPUT jack. Use a 9V AC/DC adapter capable of delivering at least 50 mA of current to power the Slammi Plus. The center conductor of the adapter must be negative, and the outer ring positive. You may choose to order the optional Electro-Harmonix adapter that provides 9.6 Volts DC/200mA.

WARNING: Using the wrong adapter or a plug with the wrong polarity may damage your Slammi Plus and void the warranty.

Please register online at or complete and return the enclosed warranty card within 10 days of purchase. Electro-Harmonix will repair or replace, at its discretion, a product that fails to operate due to defects in materials or workmanship for a period of one year from date of purchase. This applies only to original purchasers who have bought their product from an authorized Electro-Harmonix retailer. Repaired or replaced units will then be warranted for the unexpired portion of the original warranty term.

If you should need to return your unit for service within the warranty period, please contact the appropriate office listed below. Customers outside the regions listed below, please contact EHX Customer Service for information on warranty repairs at or +1-718-937-8300. USA and Canadian customers: please obtain a Return Authorization Number (RA#) from EHX Customer Service before returning your product. Include ̶ with your returned unit ̶ a written description of the problem as well as your name, address, telephone number, e-mail address, RA# and a copy of your receipt clearly showing the purchase date.

United States & Canada
55-01 2ND STREET
Tel: 718-937-8300

Tel: +44 179 247 3258

Note: This equipment has been tested and found to comply with the limits for a Class B digital device, pursuant to part 15 of the FCC Rules. These limits are designed to provide reasonable protection against harmful interference in a residential installation. This equipment generates, uses and can radiate radio frequency energy and, if not installed and used in accordance with the instructions, may cause harmful interference to radio communications. However, there is no guarantee that interference will not occur in a particular installation. If this equipment does cause harmful interference to radio or television reception, which can be determined by turning the equipment off and on, the user is encouraged to try to correct the interference by one or more of the following measures:

• Reorient or relocate the receiving antenna.
• Increase the separation between the equipment and receiver.
• Connect the equipment into an outlet on a circuit different from that to which the receiver is connected.
• Consult the dealer or an experienced radio/TV technician for help.

Modifications not expressly approved by the manufacturer could void the user's authority to operate the equipment under FCC rules.

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