Leslie speaker

A typical Leslie speaker contains an amplifier, a treble horn and a bass speaker—though specific components depend upon the model.

A musician controls the Leslie speaker by either an external switch or pedal that alternates between a slow and fast speed setting, known as "chorale" and "tremolo".

The sound of the organ being played through his speaker received national radio exposure across the US, and it became a commercial and critical success.

Leslie worked as a radio service engineer at Barker Brothers Department Store in Los Angeles, which sold and repaired Hammond organs.

After further experimentation, he decided that splitting the signal into a rotating drum and horn helped accentuate bass and treble frequencies.

[5] Leslie manufactured the speaker to work with other organs besides Hammond, including Wurlitzer, Conn, Thomas and Baldwin.

Once amplified, the signal travels to an audio crossover, which splits it into separate frequency bands that can be individually routed to each loudspeaker.

[12] The audio emitted by the speakers is isolated inside an enclosure, aside from a number of outlets that lead towards either a rotating horn or drum.

Care is taken when attempting to service them since an incorrectly or poorly wired cable can cause permanent damage to the organ or speaker, or result in electrocution.

[21][22] It is also possible to connect multiple Leslie speakers to a single organ, by using a power relay that provides the necessary AC current.

[23] Modern products such as the Trek II UC-1A allow any instrument with a phone jack connection to use a variety of Leslie speakers.

It contained a 15-inch (380 mm) drum and the power amplifier was housed in the top of the unit, to allow easy repair.

It is 41 inches (1,000 mm) high, offers two different speeds for chorale and tremolo, and has a 40 watt tube amplifier.

[31] Hammond-Suzuki currently manufacture the 122A, a straight reissue of the 122, and the 122XB, which contains a modern 11-pin adapter, an IECC mains adaptor, line-in, and a jack socket for a footswitch to control the speed.

[33] The signal input is unbalanced, allowing a simpler connection to organs that have a built-in speaker system, such as the Hammond A100, or a Wurlitzer.

[36] By the late 1960s, gigging musicians were finding that older Leslies like the 122 were not loud enough for large venues, which led to the introduction of the "Pro Line" series.

[41] However, because they used solid-state amplifiers, they are not as highly regarded as the older tube-based Leslies, because they lack the characteristic sound when the amp is overdriven.

The 2121 is a 15-inch (380 mm) stationary speaker that uses digital signal processing to emulate the rotating drum found in older Leslies.

As the sound source is rotated around a specific pivot point, it produces tremolo (the modulation of amplitude) and a variation in pitch.

[48] The crossover is deliberately set to 800 Hz to give the optimum balance between the horn and the drum, and is considered an integral part of the speaker.

Tone differences, due to cost cutting using particle board for speaker and rotor shelves instead of the previous plywood, are evident in the Leslie's sound.

Like an acoustic instrument, a Leslie's tone is uniquely defined by its cabinet design and construction, the amplifier, crossover and speakers used, and the motors—not merely by the spinning of rotors.

[52][53] Recording Magazine's Dave Martin suggests a similar setup, with various microphone models used as stereo pairs on the horn but using an Electro-Voice RE20 on the drum instead.

[55] While the Leslie speaker is still made and sold, similar effects can now be obtained via analogue electronic devices and digital emulation.

The Uni-Vibe, a four-stage phase shifter, was specifically marketed as a low-cost Leslie substitute for guitarists, and used a foot-operated fast/slow switch similar to the combo preamp.

Hughes & Kettner's Rotosphere has received good reviews for accurately producing the sound of a Leslie speaker with a tube amplifier.

Soon afterwards, Mitchell became an organist with the Mutual Broadcasting System, and played a Hammond with the Leslie on its shows, ensuring national exposure for the sound.

[66] The Beatles first recorded with a Leslie in June 1965 when George Harrison was overdubbing one of his lead guitar parts on "It's Only Love".

[68] According to author Andy Babiuk, the band's "Tomorrow Never Knows" (1966) marked the first time that a vocal was recorded using a microphone wired directly into the input of a Leslie,[69] after John Lennon had asked for his voice to sound "as though I'm the Dalai Lama singing from the highest mountain top".

Harrison played through a Leslie in his guest appearance on Cream's song "Badge" (1969), and Richard Wright used a similar setup when recording with Pink Floyd.