User Guide for Electro-Harmonix LESTER K Stereo Rotary Speaker Simulator

Quick guide for the Electro-Harmonix LESTER K pedal. Learn how to use the rotary speaker simulation, adjust speed modes, control overdrive, and configure inputs/outputs.

Table of contents

Quick guide from the manual

The LESTER K is a stereo rotary speaker simulator designed to replicate the sound of a classic rotary speaker cabinet. It features adjustable speed modes, tube-emulated overdrive, and flexible input/output configurations. This guide covers the essential controls, operation modes, and connectivity requirements for the device.

Controls

The pedal features several knobs to shape the sound:

FAST Knob: Adjusts the rotation speed when in FAST mode. The center position replicates a real rotary speaker cabinet's fast speed.
SLOW Knob: Adjusts the rotation speed when in SLOW mode. The center position replicates a real rotary speaker cabinet's slow speed.
BALANCE Knob: Controls the mix between the low-frequency rotor and high-frequency horn. Clockwise increases horn volume (brighter), counter-clockwise decreases it (darker). Center position provides natural acoustic balance.
DRIVE Knob: Controls the amount of tube-emulated overdrive. Fully counter-clockwise bypasses the effect.
VOL Knob: Controls the overall output volume.

Footswitches and Indicators

BYPASS Footswitch: Selects between buffered bypass mode and effect mode.
SPEED/BRAKE Footswitch: Tap to switch between FAST and SLOW modes. Press and hold for at least half a second to enter BRAKE mode.
LED: Indicates effect mode. Pulses between green and orange at the speed of the low-frequency rotor oscillation.

Operation Modes

The LESTER K operates in three distinct modes:

FAST Mode: Oscillates at the fast speed of a rotary speaker unit for a tremolo-like effect.
SLOW Mode: Oscillates at the slow speed of a rotary speaker unit for a chorale-type effect.
BRAKE Mode: Gradually decelerates the rotation to a stop. The LED holds steady at one color. Tap the SPEED/BRAKE footswitch to return to the previous mode.

Connectivity and Power

Inputs: LESTER K supports mono or stereo inputs. Use the MONO/L jack if using only one input. Input impedance is 2MΩ.
Outputs: Features true stereo output. Use MONO/L and R jacks for stereo. For mono output, use the MONO/L jack. Output impedance is 680Ω.
Power: Requires 135mA with a center negative plug. Use the supplied EHX9.6DC 200mA AC Adapter.

Practical help

Common problems

Device does not power on or function correctly

Ensure you are using the supplied EHX9.6DC 200mA AC Adapter. The unit requires 135mA and a center negative plug.

Sound is too bright or too dark

Adjust the BALANCE knob. Turn clockwise for a brighter sound (more horn) or counter-clockwise for a darker sound (more rotor).

Overdrive effect is not audible

Ensure the DRIVE knob is turned clockwise. If it is set fully counter-clockwise, the overdrive effect is bypassed.

Before use

Verify the power supply is the EHX9.6DC 200mA AC Adapter.
Ensure the power plug is center negative.
If using a single input, connect to the MONO/L jack.
If using a single output, connect to the MONO/L jack.
Set the BALANCE knob to the center position for a natural acoustic balance before fine-tuning.

Specs in practice

Input Impedance: 2MΩ at each input jack.
Output Impedance: 680Ω at each output jack.
Power Requirement: 135mA current draw.

Model compatibility

Supports both mono and stereo input configurations.
Supports both mono and stereo output configurations.
Compatible with standard mixing board inputs and guitar amplifiers.

Show more Show less

Manual page author

Emily Carter

User documentation editor

Prepares concise manual descriptions and highlights the most useful setup, operation, and maintenance information for readers.