Strymon Lex

114 Guitarist September 2011
STRYMON LEX & TECH 21 ROTOCHOIR £279 & £249
EFFECTS
6
5
4
2
3
1
A Rotary Speaker Primer
The history of Leslie’s whirly box and the electric guitar…
T
here are various theories
about who was the first
person to plug an electric
guitar into a rotary speaker –
some give credit to Buddy Guy
in 1965 when he played on
Junior Wells’ Hoodoo Man
Blues. His normal amp failed
and the studio engineer wired
him into a Hammond B3’s
Leslie cabinet. Others quote
Carole Kaye’s g uitar part on
Jewel Aken’s The Birds And
The Bees recorded at Gold Star
studios in LA. We don’t care
who came first though, we’re
just glad someone did, giving us
that glorious sound as heard on
loads of Beatles recordings
from 1966 on, as well as used by
Clapton on Cream’s Badge,
Hendrix on Little Wing and
SRV on Cold Shot to name just
three of many.
So what exactly is a rotary
speaker and how is the sound
made? Well, the archetypal
Leslie cabinet was designed as
an add-on for a Hammond
organ. Inventor Don Leslie
wanted to replicate the spread
of sound made by a pipe organ,
but instead created a definitive
sound in its own right – a
combination of both amplitude
and frequency modulation,
caused in part by the Doppler
effect, which could be
described as a rich and complex
mix of tremolo, phasing, pitch-
shifting and ambience.
While we call it a rotary
speaker, it’s not actually the
speakers in a Leslie that rotate –
the speaker components
remain stationary and their
sound is directed by rotating
objects: a horn and a drum in
the classic early units and just
a drum in some later models.
The original classic 122 and
147 models come complete with
an inbuilt 40-watt valve amp
feeding a crossover at 800Hz
that splits the signal to a treble
driver facing upwards in the top
of the cabinet and a 15-inch bass
speaker facing downwards. The
treble driver feeds its sound
into a rotating horn while the
bass speaker feeds into a
rotating drum with a slot
cut-out in it. Electric motors
utilising a system of pulleys
drive the horn and the drum,
with, in most Leslies, two
speeds available. A switch
attached to the organ can
change the speed from slow
(known as Chorale) to fast
(known as Tremolo) with an
extra position where the horn
and drum are stationary. When
switching from one speed to
another the acceleration or
deceleration contributes to the
complexity of the sound – the
horn being lighter than the
drum means it can speed up
and slow down faster, with the
effect that the upper
frequencies change faster than
the lower ones.
Normally connected to a
Hammond via a multi-pin
cable, the early uses of a Leslie
with guitar required breaking
into the circuitry, as the Abbey
Road engineers did for John
Lennon’s vocal in The Beatles’
Tomorrow Never Knows.
Things, however, became easier
with the introduction of the
Combo Pre-Amps, large
stompbox-style units that
connected to some Leslie
models through the Leslie cable
and featured jack sockets for
plugging in guitars or other
keyboards, with footswitches
available for speed changes.
Later Leslie designs
abandoned valves for
transistors and some Leslies
were produced with no inbuilt
amp, which is where another
well-known name enters the
arena – the Fender Vibratone,
which came about after the
takeover of both Leslie and
Fender by CBS. Relatively
portable and looking more like
a regular guitar cab than the
larger wooden ‘furniture’
Leslies, the Vibratone was a
version of the Leslie model 16
with a 10-inch speaker feeding
a rotating drum to deflect the
sound mainly out of side and
top vents. With a jack socket
input, it could be driven directly
from a guitar amp.
Besides the Leslie and Fender
models, other companies have
released rotary speakers over
the years. New models are
available from Motion Sound,
Mahaffay amps (Little Lanelei)
and also Hammond, with the
Leslie G27 and G37 for guitar.
7
Inside a Leslie 122
Three Great Rotary
Speaker Moments
1 Two-speed horn rotor
This bit spins around, using
sound from the…
2 Treble speaker
The high frequencies come out
here. Typically above 800Hz,
and the rest comes from the…
3 Bass speaker
Below 800Hz here, natch.
4 800Hz Crossover
This splits the frequencies
from the amp section
5 40-watt amplifier
The 122 used a simple amp
with a pair of 6550 valves
6 Two-speed drum
This rotating drum creates the
Doppler effect down below
7 Signal input
A six-pin plug designed for
direct connection to a
Hammond B3 – the biggest
barrier to entry if you’re trying
to use it with guitar.
Artist: Stevie Ray
Vaughan and
Double Trouble
Song: Couldn’t Stand The
Weather, title track (1984)
Everyone talks about Cold
Shot, but CSTW is packed
with Fender Vibratone – listen
to the rhythm guitar intro and
the mix in the solo section.
Artist David Gimour,
Pink Floyd
Song Shine On
You Crazy Diamond
Wish You Were Here, (1975)
Gilmour’s massive tone owes
a debt to the humble Leslie, a
sound he’s used since the late
sixties. As well as famous
recorded examples, it also
featured in his main live rig.
Artist Kim Thayil,
Soundgarden
Song Black Hole
Sun, Superunknown, (1994)
Chris Cornell came up with
the rhythm guitar arpeggio
while playing through a Leslie
speaker cab. Played by Thayil
in the studio, it ended up
defining the whole song.
GIT346.rev_strymon.indd 114 8/11/11 4:28:45 PM