Leslie 22h User manual

LESLIE

ORGAN SPEAKER

PIPE VOICE OF THE ELECTRIC ORGAN

ODEL 22H

ODEL 22R

HAMMOND

ORGAN

OWNER'S MANUAL

INSTRUCTIONS, SERVICE INFORMATION

AND PARTS LIST

ELECTRO

PASADENA (BJ <

MUSIC

CALIFORNIA

1VJH 5

CONTENTS

Amplifier, servicing information -16

Bass speaker 17

Bass speaker, removal and replacement 19

Bass rotor removal and replacement 19

Bearings replacement 19

Belt replacement, upper and lower 18

Belt tension adjustment 18

Brilliance of sound 16

Broadcasting with the Leslie Speaker 7

Cables, connecting 6

Cables, connecting, multiple installations 9

DIAGRAMS AND SCHEMATICS

A- 100 installation 3

Amplifier _15,23

Connecting cables 6

Large models installation 4

L-100 installation 2

M-l installation 2

M-2 installation 2

M-3 installation 2

M-100 installation .2

Multiple speaker installations 11, 12, 13

Multiple speaker installations guide 14

Parts identification 20

Power relay, 5A 9

Tremolo control, 428 15

Type 2adapter 15

3H echo control 15

3M echo control 15

Distortion 16

EARLY LESLIE SPEAKERS

Modification of 10

Operation 9

Tremolo control (228) 10

Echo (speaker selector) controls 10

ECHO CONTROL INSTALLATIONS

3H, for large models without built-in speakers 11

3H, for the A-100 model 3

3M, for Models M-l, M-2, M-3 1,

Electric brake 17

Electrolytic condensers 17

Fuse 16

Hammond tone cabinets, use of 8, 10, 11, 12, 14

High fidelity use of the Leslie Speaker 7

Horn reflector replacements 19

Idler pulley 19

INSTALLATIONS

A-100 3

Large models (without built-in speaker systems )4

Models M-l, M-2, M-3 1,2

Multiple speaker installations 8

Single speaker installations 1

Line voltage 17

Loudspeaker system and dividing network 17

Maintenance, periodic 6

MOTORS

Disassembly and cleaning 18

Removal and replacement 18

Oiling -.- 6

Other (non-organ )usage of the Leslie Speaker 7

Parts list 21

Phasing, multiple speaker installations 9

Power requirements 9

Preparing the speaker for use 1

Recording with the Leslie Speaker 7

Reflector replacements, horn 19

Replacement parts 16

Reverberation unit installation 7, 8

Screen voltage regulation 16

Servicing and technical information 16

Shipping 7

Speaker selector (echo) controls 10

Specifications 1

Transformer replacement 17

TREMOLO

Control, operation of 5, 16

Control in multiple installations 13

Control voltage, special handling 12

Effects, special 5

Rotor cycling 5

Rotor removal and replacement, bass 19

Rotor removal and replacement, treble 19

Speed adjustment 1

Tubes 6, 17

Voltage readings 17

Volume control setting, multiple speakers 9

Volume control setting, single speaker 5

THE LESLIE SPEAKER

Models 22H &22

The Models 22H and 22R Leslie Speakers are

expressly designed for use with the Hammond Organ.

Functionally the two cabinets, as shipped from the

Electro Music factory, are identical. However, the

22R has been prepared for easy installation of the

spinet-type Hammond reverberation kit. Procedures

for connecting the Leslie Speaker will vary according

to the model Hammond Organ which is involved. De-

tailed installation information is contained in this

manual.

The Leslie Speaker is highly efficient since it has

been created exclusively for organ usage. Broad

frequency response is obtained as the result of the

separate handling which is given to upper and lower

frequencies. The unique tremulant produced by the

Leslie Speaker is the result of moving elements, which,

by creating afully realistic tremulant, bring to the

organ atype of sound which is truly characteristic of

the pipe organ. Tremulant is controlled in the Leslie

Speaker simply by turning these moving elements on

or off.

The Leslie Speaker may be used on Hammond

two-manual models which are equipped with built-in

speaker systems, as well as on models without built-

in speaker systems. With the former models aspeaker

selector switch ("Echo") is used to enable the organist

to use the Leslie Speaker and the organ's built-in

speaker system either separately or together. An Echo

switch is also used with the larger Hammond consoles

—those without built-in speaker systems —in instal-

lations employing two or more speaker units.

Complete instructions, for avariety of Leslie Speaker

installations, and for all two-manual Hammond Organ

models, arc given in detail in this owners manual.

SPECIFICATIONS

Cabinet: Selected hardwood veneers with quality lac-

quer finish to blend with consoles.

Dimensions: 29" wide, 20y

2"deep, 41" high.

Speakers: Treble?—compression-type driver, permanent

magnet, 16 ohms impedance,

Bass —15-inch heavy duty, permanent mag-

net, 16 ohms impedance.

Amplifier: 40 watts output.

Power Supply: 117 Volt, 60 Cycle.

Power Consumption: 2.1 Amps, 190 Watts.

Weight—22H: 135 pounds net

152 pounds, boxed for shipment

22R: 138 pounds net

155 pounds, boxed for shipment

PREPARING THE SPEAKER FOR USE

After unboxing the Leslie Speaker:

1. Remove the upper and lower compartment back

covers; take out the box in the upper compartment

containing the 428 Tremolo Control, the B-f

Adapter, and the lubricating oil. If cabinet is a

22R, also remove the kit of materials for installing

reverberation unit.

2. Remove the wood shipping blocks from the upper

and lower motors and from the amplifier, so that

these units may float freely on their rubber mount-

ings. Save the wood blocks for possible future use

in shipping the cabinet. Also remove the rubber

bands, and in the case of the 22R, the tape used

to hold the upper rotor in position during ship-

ment.

3. Make sure the upper belt is in place on the rotor,

idler, and motor pulleys.

4. Select the groove on the upper motor pulley which

provides the desired tremolo speed. The center

groove is the one used most often; faster or slower

speeds may be obtained by use of the other pulley

grooves.

5. Replace the upper and lower compartment back

covers.

6. Remove shipping skid and place the cabinet so it

rests solidly on the floor. If floor is uneven use

snug-fitting wedges to keep cabinet from rocking.

7. Plug the speaker connecting cable into the Leslie

amplifier. This may be either the 5-conductor cable

(with 6-pole plug) as supplied by Hammond, or

the 6-conductor cable which is obtainable as an

accessory from Electro Music.

Note: Complete preparation of the 22R Leslie Speaker

may involve installation of the reverberation kit.

To make this installation, follow the instructions

given on page 7.

INSTALLATIONS

USING ASINGLE LESLIE SPEAKER

Those installations using asingle Leslie Speaker are

the most common, hence will be discussed first in this

manual. Installations using several Leslies, or com-

binations of Leslie Speakers and Hammond tone

cabinets will be explained in subsequent pages. The

method for connecting asingle Leslie Speaker will

vary according to the model Hammond Organ which

is being used. Complete details will be found in the

following several sections of this manual.

Connecting the Model 22H or 22Rto the Hammond

Spinet, Models L-100, M-l, M-2, M-3, or M-100

When the Leslie Speaker is to be connected to any

of the Hammond Spinet model organs, the Leslie 3-M

Echo Control Kit should be used. This kit contains

the needed connecting cable —in this case a30-foot

length of cable with appropriate connectors installed

at both ends. Also included in the kit is the switch

with associated equipment for the Echo Control, a

device that permits the organist to use either the

Leslie or the console speaker, or to use both speakers

at the same time. A428 Tremolo Control, furnished

with the speaker, provides the means for turning the

Leslie tremolo on and off.

Installation should be made as follows;

1. Attach the tremolo and echo control cases to the

wood rail directly in front of the lower manual

by choosing the two mounting holes in each con-

trol case which best center the wood screws in the

rail. Use the screws which are provided. Controls

may be located together at either end, or with one

at each end of the rail.

2. Pass the control cables into the interior of the con-

sole in one of the following ways

a. Push the cables through the felt dust seal found

underneath the manuals just above the knee

panel. (Use asmall screwdriver to push the felt

down to create an opening near the left end of

this seal.) Push the cables through this opening.

b. Run the cables down along the corner where

the knee panel and the end of the console join,

then underneath to the back of the console.

Bring the cables into the console from the rear.

3. Mount the tremolo and echo terminal boxes inside

the console at aconvenient point, making sure that

the connecting and control cables will reach.

Fasten the boxes in place using the wood screws

which are provided.

4. Connect the wiring exactly as shown in the follow-

ing diagrams. NOTE: In using the wire nuts be

sure to hold the wire ends parallel and together,

but do not twist them. Insert these ends into the

opening of the nut, pushing firmly and turning nut

in aclockwise direction until the connection is

made secure.

5. Secure the external speaker cable at the lower right

(treble) corner of the console, using the clamp

which is supplied. When all the indicated con-

nections have been made, the installation is com-

plete except for possible regulation of the volume

setting. This should be done, as needed, according

to the instruction given on page 5.

MODELS M-1, M-2, M-100, L-100 CONSOLE INSTALLATION

ECHO

CONTROL

CONNECT THIS BLACK WIRE TO

AMPLIFIER GROUND SCREW ON:

MCONSOLES WITH StRIAL

NUMBERS 8EL0W 3000

LEAVE THIS BLACK WIRE

DISCONNECTED AINSULATE

IT WITH TAPE ON:

M&U-2 C0NS0LL5 WITH

SERIAL NUMBERS ABOVE

3GGG

L-1CG CONSOLES

M-100 CONSOLES

BE SURE TO USE ALL

INSULATING SLEEVES

0R& WIRES FROM

VOICE COIL* TERMS

TREMOLO

CONTROL

MODEL M-3 CONSOLE INSTALLATION

IF TREMOLO CONTROL IS NOT

TO BE INSTALLED, CONNECT THESE

RED AND BLACK WIRES DIRECTLY TO

SCREW TERMINALS ON ECHO BOX.

CABLE AND CONNECTOR (6 POLE)

FOR EXTERNAL SPEAKER

CONNECT UNDER CONVENIENT LESUE ^ADAPTER

6M0. SCREW ON AMR IPLUG INTO AMP.

N^W, socket

L3f

BROWN WIRE NOT USED

CUT SPADE LUGS ON GRY4BLU

WIRES AND SOLDER AS SHOWN

CONSOLE

PREAMP

REI fiLK

®®

ECHO MATCH

COLORS

BRWW

CONNECT THIS BLACK VI RE

TO AMPLIFIER GROUND

SCREV OH

M-3 CONSOLES BELOW 107700

WITH AMPLIFIER CODED G,H,

or I

LEAVE THIS BLACK WIRE

DISCONNECTED AINSULATE

WITH TAPE ONi

M-3 CONS0UES SERIAL 4B000

hABOVE WITH AMPLIFIERS

CODED A^C.D.E, &F. (UN-

CODED AMP. DENOTES CODE A

M-3 CONSOLES SERIAL 107700

&ABOVE WITH AMPLIFIERS

COOED JAABOVE

ORGAN

CONSOLE

SPEAKER

3M-2 ADAPTER

INCLUDED IN KIT

BE SUftE TO USE

ALL INSULATING SLEEVES

TO SPEAKER SOCKET

ON AMPLIFIER

Connecting the Model 22H or 22R Leslie Speaker

to the Hammond Model A-100 Organ

When the Leslie Speaker is to be connected to the

Hammond Model A-100 Organ, the Leslie A-100 Echo

Control Kit should be used. The kit contains the re-

quired connecting cable assembly as well as the 3H

Echo Control. This control enables the organist to

channel the organ's output to the Leslie Speaker, to

the console speaker, or to both speaker systems at the

same time. A428 Tremolo Control, furnished with

the speaker, provides the means for turning the Leslie

tremolo on and off.

The Leslie Speaker is connected to the Hammond

Model A-100 Organ by following the steps described

below:

1. Attach the tremolo and echo control cases to the

wood rail directly in front of the lower manual

by choosing the two mounting holes in each con-

trol case which best center the wood screws in

the rail. Use the screws which are provided.

Controls may be located together at either end, or

with one at each end of the rail,

2. Pass the control cables into the interior of the

console in one of the following ways:

a. Push the cables through the felt dust seal

found underneath the manuals just above the

knee panel, (Use asmall screwdriver to push

the felt down to create an opening near the

left end of this seal.) Push the cables through

this opening into the generator compartment,

then reach behind the starting motor and pull

the cables through.

b. Kun the cables down along the corner where

the knee panel and the end of the console are

joined, then underneath toward the back of

the console. Remove the back of the console

and cut asmall notch in the bottom shelf to

provide access for the cables to the interior of

the console.

3. Mount the tremolo and echo terminal boxes inside

the console at aconvenient point, making sure

that the connecting and control cables will reach.

Fasten the boxes in place using the wood screws

which are provided.

4. Remove the jumper wires between the gray and

black terminals and between the blue and red

terminals on the console amplifier. These jumper

wires arc inside the amplifier, as indicated in the

schematic diagram.

10,

12.

Remove the red and black wires from the console

pre-amplifier "G-G" terminals which are located

near the tone control. Attach these two wires to

the "Main" terminals on the 3H Echo terminal

box, using the spade lugs which are provided.

Attach the red and black wires from the 3H Echo

terminal box to the "G-G" terminals just vacated.

Attach the 4-wire echo control cable to the 4-wirc

cable from the 3H Echo terminal box, matching

all the colors, and using the wire nuts which arc

provided. NOTE: In using the wire nuts, be sure

to hold the wire ends parallel and together, but do

not twist them. Insert these ends into the opening

of the nut, pushing firmly and turning nut in a

clockwise direction until the connection is made

secure.

Attach the wires from the 428 Tremolo terminal

box:

Red and Black wires to the "echo" terminals on

the 3H Echo terminal box.

Brown wire to the brown wire on the octal tube

adapter, using the spade lug connection, and

pushing the insulating sleeve over the terminal

after the connection has been made.

Yellow wire to aconvenient ground connection.

Remove the 5U4-GB tube from the console ampli-

fier, then insert the octal tube adapter into the

vacated socket. Finally, insert the 5U4-GB tube

into the adapter.

Using the blue and gray wires which are furn-

ished, make aconnection between the terminals of

the 428 Tremolo terminal box, and the blue and

gray terminals on the console amplifier.

Attach the 2-wirc tremolo cable to the 2-wire

cable from the 428 Tremolo terminal box, using

the wire nuts which arc provided. Be sure to

follow the previously explained procedure in using

the wire nuts.

Insert the plug of the 727-5 Adapter into the extra

speaker socket on the A-100 Amplifier, then insert

the connecting cable plug into the adapter. The

receptacle at the opposite end of the cable is to

be connected to the amplifier in the Leslie

Speaker. The installation is now complete except

for the regulation of the volume, as may be re-

quired. The volume control should be set accord-

ing to detailed instructions on page 5.

OCTAL TUBE

ADAPTER

TREMOLO

CONTROL

WIRE MJTS

HOLD WIRE ENDS PARALLEL AND

TOGETHER 9UT 00 NOT TWIST.

WHILE PUSHING WIRES FIRMLY

IfMTO MOUTH OF NUT, SCREW ON

WIRE NUT.

FURNISHED WITH LESLIE

A- 100 KIT —

INSULATING

SLEEVE

MATCH

COLORS

A-100 PREAMPLIFIER (UPSIDE D0WM)

RED

BLACK GROUND

BLACK

khov

K0RIG1IMAL WIRES TO PREAMPLIFIER G-G

428 TREMOLO TERMINAL 60/ o-H ECHO TERMINAL BOX

LESLIE

CABINET 727 CABLE

D-

(JJ

NPUT SPEAKER

A-100 POWER AMPLIFIER

Connecting the Model 22H or 22R

Leslie Speaker to Hammond Models

Without Self-contained Speakers

For Hammond Models A, B, C, D, E, BV, CV, B-2,

C-2, RT-2, B-3, C-3, RT-3, the connection is made

between the organ console and the Leslie Speaker by

means of the regular connecting cable which is furn-

ished with the Hammond console. A428 Tremolo

Control, furnished with the speaker, provides the

means for turning the Leslie tremolo on and off.

The Leslie Speaker is connected to any of the above-

named Hammond models by use of the following pro-

cedures :

1. Attach the tremolo control case to the wood rail

in front of the lower manual, choosing the two

mounting holes in the case which best center the

wood screws in the rail. Use the screws which are

provided. The Tremolo Control may be located at

either end, although the location at the left end,

directly in front of the pre-set keys, is generally

preferred.

2. Pass the control cable into the interior of the con-

sole in one of the following ways

a. Push the cable through the felt dust seal found

underneath the manuals just above the knee

panel. (Use asmall screwdriver to push the felt

down in order to create an opening near the left

end of this seal.) Push the cable through this

opening into the generator compartment, then

reach behind the starting motor and pull the

cable through.

b. Run the cable down along the corner where the

knee panel and the end of the console are

joined, then underneath toward the back of the

console. Remove the back of the console, and

cut asmall notch in the bottom shelf to provide

access for the cable to the interior of the con-

sole.

3. Mount the tremolo terminal box inside the organ

console at aconvenient point, making sure that the

connecting and control cables will reach. Fasten

the box in place using the wood screws which are

provided.

4. Connect the two-wire cable from the tremolo con-

trol to the two-wire cable from the tremolo terminal

box, using the wire nuts which are provided.

IMPORTANT: When using wire nuts be sure to

hold the wire ends parallel and together but do not

twist them. Insert these ends into the opening of

the nut, pushing firmly and turning nut in aclock-

wise direction until the connection is securely

made.

5. Remove the wires from the "G-G" terminals on the

pre-amplifier, and connect them to the screw term-

inals of the terminal box. NOTE: In the case of

Hammond models B-3, C-3, and RT-3 all con-

nections at the pre-amplifier are solder-type con-

nections.

6. Attach the red and black wires from the terminal

box to the "G-G" terminals on the pre-amplifier

which were vacated in step 5.

7. Attach the yellow wire from the terminal box to

any convenient ground screw.

8. The brown ivire from the terminal box is to be con-

nected on the basis of the Hammond model in-

volved:

Models A, B, C, D, E, BV, and CV only:

Attach to the pre-amplifier B-j- terminal along

with the wire (to the cable outlet box) already

connected there.

Models B-2, C-2, and B.T-2 only:

Attach to the brown wire on the Octal Tube

Adapter (Part No. 428-9) which is furnished as a

part of the 428 kit. Once the connection is made

push the plastic insulating sleeve over the terminal.

Remove the 6X5 tube from its socket on the pre-

amplifier chassis, plug the adapter into this socket,

and the 6X5 tube into the socket on the adapter.

Models B-3, C-3, and RT-3:

Attach to the brown wire on the 7-pin adapter

(Part No. 428-8) which is furnished as apart of

the 428 kit. Once the connection is made push the

plastic insulating sleeve over the terminal. Remove

the 6X4 tube from its socket on the pre-amplifier

chassis, plug the adapter into this socket, and the

6X4 tube into the socket on the adapter.

9. Complete the installation by connecting console

and Leslie Speaker, using the cable which is sup-

plied with the Hammond console. The plug at one

end of the cable is to be connected to the socket on

the outlet box in the console; the receptacle at the

other end of the cable plugs into the amplifier on

the Leslie Speaker. The installation is now com-

plete except for the regulation of the volume, as

may be required. The volume control should be

set according to detailed instructions on page 5.

TREMOLD

CONTROL

ATERMINAL

BOX

MOLD WIRE: ENDS

PARALLEL AMD

TOGETHER BUT DO

NOT TWIST. WHILE

PUSHING WIRE

FIRMLY INTO MOUTH

OF NUT, SCREW ON

WIRE NUT.

TYPE 2TREMOLO CONTROL

INSTALLATION IN CONSOLE

ORIS, WlttS

FROM GS

PREAMP

TERMINALS

LESLIE 6* ADAPTER TO BE INSERTED BETWEEN

INDICATED TUBE AND ITS AMPLIFIER SOCKET

6X5

6PIN

B2,C2, RT2

63 C3

RT3

ON MODELS B3. C3. RT3

LESLIE EQUIPMENT WIRES ARE

SOLDERED TO PREAMP TERMINALS.

OTHER MODELS USE LUG CONNECTORS

UNDER SCREW TERMINALS-

A. BX. D.E, BV. CV

%~1

GCKSOLE PREAMP.

AC &* GND G6

REMOVE ONIT WIRES FROM C- TERMS. OH PREAMP,

BROWN 4

VOLUME CONTROL SETTING

The Leslie amplifier is designed purposely to have

more gain than is normally required. Thus, abroad

volume range is available. Volume should be adjusted

on the basis of the console signal output as well as

for the particular acoustic environment.

The volume level should be set on the basis of

maximum demand, avoiding distortion or overload:

1. Using afull registration, that is, with one set of

manual drawbars and both pedal drawbars pulled

out to position eight, play apedal note and afull

chord, with the Swell Pedal fully "open".

2. Advance the volume control on the Leslie amplifier

from aminimum position up to apoint where

some distortion can be heard.

3. Back off the volume control setting just far enough

to eliminate all the distortion. This then is the

correct setting for maximum undistorted loudness,

and no further adjustment will have to be made.

CAUTION:Distortion, if continuous, can ser-

iously damage speaker components.

THE LESLIE TREMOLO

One of the unique aspects of Leslie Speaker design

is the method for producing tremolo, or tremulant.

Two rotary elements within the Leslie cabinet project

the sound afull 360 degrees in amanner which results

in arealistic acoustic tremolo. This patented system

adds important musical values to the tone of the

Hammond Organ, greatly enhancing its performance.

Tremolo Control

Tremolo in the Leslie Speaker is controlled by turn-

ing the power for the tremolo driving motors on and

off. This is accomplished by means of arelay which is

built into the Leslie amplifier. The two motors plug

into AC outlets located on the amplifier.

It will be noted that there are actually three AC

outlets, located together on the amplifier. However,

only two of the outlets are under on/off control.

The third outlet, located nearest to the volume control,

is not affected by the relay, but instead supplies power

whenever the organ and speaker are turned on. (Use

of this outlet will be explained in the section on

special tremolo effects.) The Leslie Speaker, as it is

shipped from the factory, has the two motors plugged

into the two controlled outlets.

Tremolo Rotor Cycling

When the Leslie speaker is first turned on, the

rotors which are plugged into the controlled sockets

will rotate for approximately 10 seconds and then will

stop. If the Leslie tremolo switch is "on" the rotors

will immediately start again, and will rotate con-

tinuously, so long as the switch remains "on".

This initial rotor cycling is completely normal and

occurs only during the warm-up period. After this

warm-up completely normal on-off control will be in

effect.

Special Tremolo Effects

Some intriguing musical possibilities result from

having the Leslie tremolo under only partial on/off

control. In this alternative arrangement the lower

(bass) rotor is kept constantly in motion, while the

upper (treble) rotor is controlled independently by

the Leslie tremolo on/off switch. To accomplish this

the power plug from the lower driving motor is

plugged into the third AC outlet previously mentioned.

This outlet, located nearest to the volume control, is

not affected by the Tremolo switch. It supplies power

to the driving motor continuously while the organ is in

operation.

The uncontrolled outlet in the 22R cabinet will be

used whenever this cabinet is equipped with Rever-

beration kit. Thus, when the lower rotor is to be

kept constantly in motion, this outlet should be

supplied with acube tap in order to accommodate

plugs from both the reverberation amplifier and the

lower tremulant rotor.

The unusual effects that can be obtained from this

partial tremolo control arrangement become apparent

when the Leslie tremolo switch is in "off" position.

The upper tremolo rotor (treble) will remain station-

ary while the lower (bass) rotor will continue to turn.

Through choice of registration and playing range,

some effects of considerable contrast may be obtained.

For example, notes played in the top two octaves

of the keyboard, using abrilliant registration such as

Strings, will be channeled mainly through the treble

rotor. With the tremolo "off" this rotor will not be

in motion, hence these notes will have practically no

tremolo. If at the same time (still with tremolo "off")

notes are played in the lowest three octaves of the

other manual, and using abland registration such as

"Tibia", the sound will be heard mainly through the

bass rotor which is revolving and which will thus pro-

duce afull tremulant. The "solo" part may be played

on cither keyboard, with the "accompaniment" on the

other. Due to the contrasting tremolo treatment

which is given to the two individual playing ranges,

with tremolo "off", the tonal difference between

"solo" and "accompaniment" parts is quite substantial.

Utilization of these special tremolo possibilities will

further be influenced by the vibrato system of the

particular console. Where the instrument is equipped

with electronic vibrato, the vibrato control knob

should be set at Number 1. If the vibrato is controlled

separately for the two manuals many combinations of

acoustical tremulant and electronic vibrato become

possible. Areasonable amount of experimentation

here will reveal many interesting musical possibilities.

Early model consoles were equipped with an ampli-

tude-type tremulant, and in many cases with achorus

generator as well. Both these devices alter the organ s

signal in such away as to make it incompatible with

the Leslie tremulant. Hence, on these early Hammond

consoles neither the tremulant nor the chorus gen-

erator system should be operated at the same time

that the Leslie tremulant is being used.

On Series 3consoles which are equipped with the

Hammond Percussion, the Leslie Speaker makes pos-

sible many interesting tonal combinations. Since the

electronic vibrato is not applied to the percussion out-

put, the only tremulant will be supplied by the Leslie.

The Leslie tremulant may be turned off for those

effects that are best without tremulant, or it may be

used to provide tremulant for such interesting effects

as the "Vibra-harp". Again, reasonable experimenta-

tion with the combination of percussion and Leslie

will result in the discovery of agreat many usable

new sounds.

CONNECTING CABLES

The "standard" type speaker-connecting cable, as

supplied bv Electro Music, contains six conductors.

Current models of lx>th the Hammond Orgsm and the

Ix^Iic Speaker actually use only five of the six con-

ductors in this cable/ However, all six conductors

are used with early consoles and speakers. Since these

units continue to be used in installations it seemed

advisable to standardize on cable which would Ik*

adequate for all installation requirements. Adaptation

to the individual speaker and/or organ model is then

amatter of selecting the proper terminal connectors,

as explained in the chart.

The ^conductor connecting cable is supplied in

standard 30-foot lengths complete with plugs and/or

connector terminals.

The cable with 6-pole connectors at both ends b

Leslie Ptart No. 727.

The cable with aplug at one end and "spade-lug*

connector terminals at the other end is I-eslte Part

No.3M-l«

To span distances between console and speaker of

more than 30 feet, the cable from the console may be

supplemented bv one or more 727 cable assemblie s

connected together in series, used as extensions.

In certain installation* ;i specific length of cable

other than 30 feet is required. In such cases bulk

cable should be ordered, along with the necessary

connectors, as Specified in the rents list. (Note: The

spade lugs should Ik? obtained from alocal radio parts

supplier.) lit attaching tin* cable tn the connectors or

to the "spade-lug" connector terminals be sure to

follow the color coding as shown in the cable chart

below. Special care should he given to the handling

of all connections involving AC.

DESCRIPTION

727 CABLE ,COVPtfTC

(INCLUDED IH A-100 KIT)

3W-I CABLE,- COMPLETE

(INCLUDED IN 3U KIT)

721-1 WU CABU tSPCCIFY LEKCTKJ

727*3 SOClCtT (e-CONUCT) AND C4f

727-4 PLUS (5-POU) AND CAP

727-1 BUU CABLE tSPCCIFY LERGTH)

MECHO CONTROL KIT INCLUDES:

727-3 SOCKET AMD CAP

SPADE LUGS

ASSEMBLY DETAIL USAGE

EARLY CONSOLE TO SPEAKER

EXTENSION -rROy CONSOLE

CABLE TO SPEAJCER

EXTENSION •fROM SPCACER

CABU TO ANOTHER SPEAKER

CURRENT HAifttiNO CONSOLE TO

CURRENT LESLIE SPEAKER

CURRENT CONSOLE TO

ICAIM SPEAKER

CURRENT CONSOLE TO

ECHO SPEAKER

SPEAKER TO SPEAKER

CONSOLE TO ECHO SPEAKER

RECOMMENDED

PERIODIC MAINTENANCE

The Leslie Speaker is carefully engineered for

durahilitv and minimum service. Periodic lubrication

and atew simple checks will result in efficient

operation.

Oiling

Oil the two tremulant motors bv placing 20 to 30

drops of the oil which is furnished (or sewing machine

oil) in each of the oil tubes at the back of tlie cabinet.

The motors should be oiled every six months for

normal usage, every three months for commercial

upper tremulant rotor should be oiled every

year under normal operating conditions, every six

months if in commercial usage. The oil hole is found

at the center of the hakelite tremulant assembly, and

is clearly marked. Place about five drops of oil in the

hole, allowing it to drop slowly so as to avoid over-

flow at the opening. Be very careful to prevent oil

from getting onto pulley grooves or driving belt.

Belts

For average service belts usually last several years.

However, since frayed or badly worn belts can cause

noise, tliey should be examined periodically, and re-

placed as necwary.

Tubes

Check periodically to see that all the tubes on th

amplifier are illuminated, and are functioning properly.

The weakening of tubes with long use is such agradual

process that the resulting sub-standard performance

may not at first be noticed. New tubes, if carefully

checked* will restore the speaker to its original oper-

ating efficiency. For best results it (s recommended

that the tubes be replaced before appreciable de-

terioration has occurred.

SPECIAL USES OF THE LESLIE SPEAKER

Broadcasting and Recording

To obtain full rich pipe-organ effects, the organ

should be played at afairly high volume, using alive

studio. The microphone should be placed ten to

fifteen feet away from the Leslie. For asmooth

tremulant, adjust the microphone height so that it is

either above or below the upper speaker louvres in the

cabinet,

Non-Organ Use of the Leslie Speaker

The Leslie Speaker is aproduct of superb quality,

designed solely and expressly for use with electric

organs. It does not function satisfactorily in other

applications. The unique musical characteristic of

the speaker is the result of electrical and acoustical

properties totally different from those found in "high-

fidelity" sound equipment. This specialized concept

upon which the Leslie Speaker is based restricts its

recommended usage to the electric organ.

SHIPPING

The Leslie Speaker may be moved or carried in any

position without special preparation. However, if it

is to be shipped, the cabinet should be in an upright

position, with shipping blocks in place to protect the

motor, rotor, and the power amplifier.

In the case of the 22R, tape should also be used to

hold the upper rotor down securely on its base. The

reverberation unit also should be "locked".

INSTALLATION OF REVERBERATION UNIT

IN THE MODEL 22R LESLIE SPEAKER

The Model 22R Leslie Speaker is functionally the

same as the Model 22H; as shipped from the factory

the 22R may be used in exactly the same way as the

22H. The 22R, however, is designed to receive the

Hammond Reverberation Kit. All mounting holes are

pre-drilled, and are properly located for easy in-

stallation of the major assemblies of the reverberation

device. While it is preferable to install the 6X9 rever-

beration speaker on the right side of the Leslie cabinet

(as viewed from the back), it may be that in the

placement of the Leslie, this side of the cabinet is so

close to the wall as to prevent the sound from radiating

properly. In such cases the 6X9 reverberation speaker

may be mounted in the left side of the cabinet, which

is also supplied with louvres and pre-drilled holes.

Complete installation details are provided for use of

both speaker locations.

The Hammond spinet-type Reverberation Kit, with

console-type speaker, includes all major assemblies as

well as some of the small parts for the installation.

The remainder of the parts are either contained in the

kit of materials supplied with the 22R speaker, or will

be found already in the cabinet. The following parts,

included in the Hammond kit, are to be used in the

installation —other parts may be discarded:

Reverberation amplifier with blue and black line cord

attached.

Reverberation unit with blue and black wires attached.

Reverberation unit guide bracket.

Console-type 6X9 speaker with volume control and

green and black wires attached. (Remove speaker

from the wooden console speaker box.

)

Amplifier shield base (aluminum foil.

)

Two #4 xsheet-metal type screws for guide

bracket.

Six #8 xsheet-metal type screws, for reverberation

unit (2) and for speaker mounting (4).

NOTE: In addition to the usual service tools, the

reverberation installation will also require use

of "stubby" screwdrivers for the regular

slotted-head screws and for the Phillips head

screws.

Installation of the Hammond Reverberation device

is to be made as described below. It is necessary that

all three back panels be removed in order to provide

unrestricted access to the interior of the cabinet.

Specific directions (left, right) will be oriented on the

basis of viewing the cabinet from the back.

1. Remove the four 10/24 x7

/8"machine screws from

the amplifier mounting holes in the left-hand side

of the upper shelf. Place the aluminum foil shield

on this shelf, aligning the holes in the shield with

the mounting holes in the shelf. Place the two

felt strips at the ends of the shield, again aligning

the holes in the felt with the mounting holes in

the shelf. Mount the reverberation amplifier over

the shield and the felts, with the terminal strip

facing the horn assembly. Fasten the amplifier in

place using the previously removed machine

screws. Fasten at three points, but not at the

right rear corner of the amplifier chassis. The

bracket for the volume control is to be installed

there, as will be explained in step number 8.

2. Take out right-hand wood speaker-cover box by

removing the wing nut and angle bracket which

hold it in place.

3. Mount the reverberation unit guide bracket as-

sembly on the shelf to the right of the bass

speaker, using the pre-drilled mounting holes.

Be sure that the springs in the assembly face away

from the side of the cabinet. Fasten the assembly

in place with two of the #4 x%" screws.

4. Insert two of the #8 x%" screws into the pre-

drilled holes midway in the right side panel of

the cabinet, and tighten them down to approxi-

mately 3/32" from the surface.

5. Insert the vertical channel of the reverberation

unit between the springs of the guide bracket,

then hang unit on the screws which were installed

in step 4. Check to be sure that mounting slots of

the reverberation unit are properly seated over the

mounting screws and that the vertical channel is

still in place between the springs of the guide

bracket. Finally, tighten the mounting screws.

6. After the 6x9 speaker has been removed from the

wooden console speaker box, it should be pre-

pared as follows for installation in the Leslie

cabinet

a. Cut the green and black wires leading to the

speaker volume control about 2l

zinches from

the speaker. Strip about l

/2inch of insulation

from the ends of the two wires leading to the

speaker.

10,

b. Using wire nuts, connect the green and black

jumper wires (furnished in the Leslie kit) to

the two wires from the speaker. Speaker is

now ready for mounting, (The volume control

assembly previously cut off will be used later

in the installation.) IMPORTANT: When

using wire nuts be sure to hold the wire ends

parallel and together but do not twist them.

Insert these ends into the opening of the nut,

pushing firmly and turning nut in aclockwise

direction until the connection is securely made.

To mount the 6x9 reverberation speaker on the

RIGHT-HAND side, simply locate it properly

over the pre-drilled mounting holes behind the

louvres on the right-hand side. Fasten in place

using four of the #8 x%" screws. Replace the

wood speaker-cover box, threading the green and

black speaker wires out through the slot in the

box. Secure box in place, using the mounting

bracket and wing nut removed previously. Should

it be desirable to mount the reverberation speaker

on the LEFT-HAND side, these steps should be

followed:

a. Remove the bracket and the long screw which

are used to secure the speaker-cover box in

position, and remount these in the left side of

the cabinet, using the pre-drilled holes.

b. Remove the wood cover behind the louvres in

the left side of the cabinet, and install on the

right side,

c. Remove the other cover from the left-side

panel and place it over the two holes in the

right side of the upper shelf, aligning the cover

with the pre-drilled holes in the shelf. Fasten

the cover in place with screws.

d. Mount the 6x9 speaker behind louvres on left

side of cabinet, using pre-drilled holes and

fastening in place with four of the #8 x%"

screws.

e. Replace the wood speaker-cover box, thread-

ing the green and black speaker wires out

through the slot in the box. Secure box in

place using the mounting bracket and wing

nut previously removed.

Mount the speaker volume control and wire as-

sembly (removed in step 6) on the metal bracket

which is furnished. Locate the control and

bracket assembly at right rear corner of rever-

beration amplifier, placing bracket base between

felt and foil. Use 10/24 x%" screw to secure both

the amplifier and the bracket.

Using wire nuts, connect the green and black

wires from the volume control to the green and

black (jumper) wires from the 6x9 speaker.

Attach the green and black wires (from the

volume control, and equipped with spade lugs)

to the "speaker" terminals on the reverberation

amplifier.

Connect the spade lugs on the ends of the black

and blue jumper assembly (furnished in Leslie

kit) to the driver terminals on the reverberation

amplifier. Connect the opposite ends of these

jumper wires to the black and blue input wires of

the reverberation unit, covering these connections

with the plastic sleeving which is also furnished.

12. Connect the shielded extension cable (from Leslie

kit) between the output wires of the reverberation

unit and the reverberation amplifier,

13. Connect the short brown wire (from Leslie kit)

across the "Switch" terminals on the reverberation

amplifier.

14. Remove the insulation covering the spade lugs at

ends of the red and black Leslie amplifier output

wires. (These wires come from the 2-polc con-

nector assembly located on the left side of the

bass speaker shelf. )Connect these wires, using

the spade lugs, to the "Signal Input" terminals on

the reverberation amplifier.

15. Attach the AC plug (from Leslie kit) to the blue

and black wires from the reverberation amplifier.

Plug into an AC socket on the Leslie amplifier,

using the socket which is nearest to the volume

control knob.

16. Dress all jumper wires together near the left side

of the bass speaker shelf. Snap the plastic cable

clip (from Leslie kit) around these wires and

fasten to the left side of the cabinet, using the

#8 xYi" screw. Thus secured, the wires cannot

vibrate and create noise.

17. Replace all three backs on the Leslie cabinet.

Unlock the reverberation unit by turning the lock

rod which is accessible under the metal cover

found near the right side of the center back cover

panel of the Leslie. To UNLOCK, turn the rod

Kturn to the right, bringing the slot of the rod

to avertical position. (To LOCK the reverber-

ation unit, the rod is to be rotated ^turn to the

left, so that the slot is horizontal. The unit

should always be LOCKED whenever the speaker

is being moved.)

18. Set the volume control for the 6x9 speaker so as

to provide the desired amount of reverberated

sound. The installation is now complete.

MULTIPLE SPEAKER INSTALLATIONS

When aparticular installation requires greater

volume than can be obtained without distortion from

asingle Leslie Speaker, additional units may be added.

Additional speakers bring an improvement in the

musical quality as well as an increase in the overall

volume. Adding speakers is like adding chests of

pipes in apipe organ: the sound is distributed over a

broad area. This effect of "bigness" is most pro-

nounced when the speakers in amultiple installation

are separated from each other by fifteen to twenty

feet. Also, the selection of adifferent pulley groove

(upper motor) for each speaker provides contrasting

tremolo effects, further enhancing the pipe organ

effect.

Amultiple speaker installation may include any

type of Hammond tone cabinet, and early model Leslie

Speakers along with the current Leslie models. Where

reverberation is involved special handling is required.

Although it is technically possible to pass the reverber-

ated Hammond signal through the Leslie Speaker, it is

not always the desirable course; in addition, the in-

stallation becomes extremely complicated. The prefer-

able course, where reverberation is desired, is to use

the Leslie Model 22R Speaker.

One of the principle differences between current

and early Leslie models is in the tremolo control

circuitry. Thus, where earlier Leslies are used in an

installation, special procedures must be followed, as

described on pages 12 and 13.

Tremolo, in amultiple speaker installation, may be

controlled for all the current model Leslie Speakers,

by asingle on-off tremolo control switch. However,

the use of two tremolo controls makes possible the

independent control of the two Leslie Speakers or two

groups of Leslies that may he used in the installation.

Power Requirements —Use of the 5A Relay

Although any number of speakers may be used to-

gether in an installation, the AC power requirements

must.be handled in such away as to avoid overloading

the console circuits. These circuits will quite easily

power one Leslie or Hammond speaker, but for each

additional speaker it is desirable to provide an outside

source of power. To accomplish this, and at the same

time to maintain complete on/off control through the

console power switch, the Leslie 5A Power Relay

should be used.

One of the 5A Power Relavs should be attached to

the input plug on each of the extra speakers. The

connector cable plugs into the 6-pole plug on the relay

and the AG cord from the relay is to be connected to

aconvenient electrical outlet.

Through use of the 5A Power Relay the console

circuits are not overloaded, although power for all the

speakers is turned on or off by the console switch.

POWER RELAY

TO 117 VAC

RELAY IS ENERGIZED

WHEN CONSOLE POWER

Wife; 15 ™NED 0H -

Volume Control Settings on Multiple Speakers

In amultiple installation, the volume control for

each one of the speakers should be set according to the

instructions given previously. (See page 5). If the

maximum levels thus obtained result in too much over-

all loudness further adjustments should be made.

It is most important that abalance be maintained

between the several speakers that may be used in an

installation. Each speaker should make approximately

the same contribution to the total sound. No speaker

should be allowed to overpower the others. Time

spent in achieving the "right" adjustment for each

speaker will greatly improve the final musical results.

Pedal Loudness

When two or more speakers are being used together

and are adjacent, they should be phased so that

with individual pedal notes the speakers reinforce

rather than cancel each other.

If improper phasing is suspected, try reversing the

red and black output leads in the two-pole plug at the

amplifier of one of the speakers. If louder pedal out-

put results from this change it should be made

permanent. However, if the pedal level is instead

reduced, the original connection should be restored,

and it may safely be concluded that the problem is

acoustical rather than one of phasing.

Connecting Cables —Multiple Installations

Cable, when supplied with aHammond console, is

the 5-conductor type, with a5-pole plug at one end

for the console connection, and a6-contact socket at

the other end of the cable for the speaker connection.

This cable may be used satisfactorily for any Ham-

mond cabinets and for current models of the Leslie

Speaker.

Early model Leslie Speakers and/or early model

Hammond Organs necessitate use of 6-conductor con-

necting cables. This standard Leslie cable is available

in bulk quantity (Leslie Part No. 727-1) or in 30-foot

lengths complete with 6-pole connectors at each end

(Leslie Part No. 727). The 6-conductor cable may be

used throughout an installation, for the Hammond

speakers and for all models of the Leslie Speaker.

Where only 5conductors are required a5-contact

socket is provided for the cable connection. The 6-pole

plug on the end of the connecting cable must then be

fitted with a5-to-6 Adapter (Leslie Part No. 727-5) to

permit the connection to be made.

Detailed information for handling specific cable

connections, and for preparing cables, will be found

in the chart on page 6.

Early Model Leslie Speakers

Tremolo rotors in the early model Leslie Speakers

are started and stopped by acontrol current which is

carried over the sixth (B-f-) wire in the connecting

cable. Tremolo control in the current model Leslie

Speakers is accomplished by means of aDC voltage

which is superimposed on the signal lines. This is

known as the "Type 2Tremolo Control system".

Special circuitry in current Leslie amplifiers uses

this superimposed DC voltage for control purposes,

yet isolates it from the signal input grids. Amplifiers

in early model Leslie Speakers and in Hammond tone

cabinets do not use this voltage, nor do they have the

necessary isolation circuitry.

Early Leslie Speakers are those with serial numbers

below 5200, Some of the 31 series Leslie Speakers are

in this category. However, most of the 31 series, as

well as all of the 21H, and the present 22H and 22R

models, are all categorized as "current" models. They

all utilize the Type 2Tremolo Control system, and are

easily recognized as current models since the serial

numbers are above 5200.

Tremolo control in installations involving early

model Leslie Speakers must be given special handling.

The DC voltage used for on/off control in the current

model Leslie Speakers will not provide the same con-

trol in the early Leslie. In fact, the DC voltage must

he completely isolated from the early Leslie, or hum,

low output, and distortion will result. Isolation of the

DC control voltage from the early Leslie is ac-

complished through use of the Type 2Adapter.

The Type 2Adapter prevents the DC control voltage

from reaching the early model Leslie Speaker ampli-

fier, yet at the same time keeps this voltage available

for additional current model Leslie Speakers, so that

they will have fully controlled tremulant operation.

The adapter doesn't affect amplifier operation in any

way. However, it does change the impedance value

on the amplifier's extra speaker socket. Therefore, any

additional speaker following the adapter must have

its cable connected to the socket on the adapter box,

rather than to the extra speaker socket on the amplifier.

The tremolo rotor operates continuously in any early

Leslie Speakers on which the Type 2Adapter is

used. Where full tremolo control is required for

the early Leslies, the console should be equipped

with a228 Tremolo Control. This would be in ad-

dition to the Type 2Tremolo Control (428) which

would still be required to control the current Leslies.

The Type 2Adapter must be used with earlier

Hammond tone cabinets in all cases where those units

are connected to the channel (Echo or Main) which

is supplied with the DC tremolo control voltage.

However, the Type 2Adapter should not be used

with Hammond tone cabinets Type PR and later. For

these units it is necessary to keep one of the channels

completely free of the DC tremolo control voltage;

by connecting the Hammond tone cabinets to this

channel the need for the Type 2Adapter is eliminated.

Such an installation, illustrated in Figure 2, page 12,

is actually preferable for all Hammond tone cabinets.

However^ it is mandatory for the PR (and later) series,

and is the only satisfactory arrangement for using these

particular tone cabinets in conjunction with current

model Leslie Speakers.

Modification of Early Leslie Speakers

Early Leslie Speakers may be modified and thus

made fully compatible with the current model Leslie

Speakers. The modification must be done at the

Electro Music factory, and since all changes are made

within the amplifier, this is the only part of the Leslie

Speaker that need be sent to the factory.

The Type 2Tremolo Control circuitry which is

installed at the time of modification is functionally

identical to that of the current Leslie models. The

same 428 Tremolo Control kit may be used, and the

Type 2Adapter is no longer necessary. Since the

428 Tremolo Control kit is not automatically supplied

as apart of the modification "package" it should be

ordered separately if required.

MULTIPLE INST

In the following several pages details are given for

the various types of multiple speaker installations.

The techniques for combining current model Leslie

Speakers with early model Leslies and/or Hammond

tone cabinets are fully explained and illustrated.

Finally, several typical installation layouts are pro-

vided, as ameans for summarizing principles which

must be followed in multiple installations:

1. To provide AC power for the second and all ad-

ditional speakers used in an installation, a5A Relay

should be used at the amplifier of all but the first

speaker.

Echo (Speaker Selector) Controls

The use of multiple speakers in an installation not

only results in greater sound volume, but also makes

possible improved sound distribution. To this end,

the several speakers that may be used in an installation

are usually separated from each other by areasonable

distance. Or, where the installation is quite sizeable,

the speakers are arranged together in groups which

are in turn separated from each other.

Since it is usually desirable that the organist be

able to use the speakers selectively, an "Echo Control"

is used to accomplish this purpose. The Echo Control

is in effect aswitching device that permits the

organist to select the speaker or speakers that will be

heard. For the purpose of convenient identification,

the speaker or speakers located nearest to the console

are usually designated as "Main'' speakers. The

speaker or speakers located at apoint more remote

from the console are then referred to as "Echo"

speakers.

Multiple speaker installations normally involve the

larger Hammond consoles —those without any built-

in speaker systems. Where an Echo Control is used

with these Hammond models, it should be the type

3H control. If, for reason of availability, it is desirable

to use some switching mechanism other than the

recommended Leslie 3H Echo Control, the circuitry

must be modified as necessary so that it is identical to

that of the 3H control. (See diagram page 15.)

Multiple installations with Hammond models having

built-in speaker systems will not afford the organist

the complete flexibility of speaker selection as will

be the case with the larger Hammond models. The

former Hammond Models, specifically the Models M

and A-100, employ an Echo Control (types 3M and

A-100, respectively) for the purpose of channeling the

sound either through the console speaker or through

the Leslie Speaker. Additional Leslie or Hammond

speakers may be connected to the first Leslie Speaker,

and wTill be heard simultaneously with it. Since one

position of the Echo Control switch is reserved for

the console speakers the other position will necessarily

activate all the external speakers. Further selective

channeling on these Hammond models with built-in

speakers becomes extremely complicated and there-

fore is not recommended.

DNS IN DETAIL

2. Early model Leslie Speakers and early Hammond

tone cabinets, when connected through the channel

that is affected by the 428 Tremolo Control, must

be connected by means of the Type 2Adapter, so

as to isolate the tremolo control voltage from these

particular units.

3. The Type 2Adapter need not be used with early

model Leslie Speakers and Hammond tone cabi-

nets, providing these speakers are connected to the

channel which does not at any time receive the

tremolo control voltage.

4. Full tremolo control for any early model Leslie

Speakers will result only from the use of the Type

228 Tremolo Control. Otherwise, the early model

Leslie Speakers will produce aconstant tremulant.

Installation of the Leslie 3H Echo Control

For Hammond Models: A, B, C, D, E, BV, CV,

B-2, C-2, RT-2, B-3, C-3, and RT-3

1. Attach the echo control case to the wood rail

directly in front of the lower manual, choosing the

two mounting holes in the control case which best

center the wood screws in the rail. Use the screws

which are provided. The echo control may be

mounted at the right end of the rail, or at the left

beside the tremolo control.

2. Mount the echo terminal box inside the generator

compartment near the pre-amplifier.

3. The echo control cable should be passed into the

interior of the console, using the same method as

was chosen for the tremolo control cable. In-

structions for the latter will be found on page 4,

item 2.

4. Provision for attaching the speaker connector cable

should be made in one of two ways

a. If an outlet box is provided in the console for

the speaker connection, remove one of the metal

knock-outs and install cither a5-contact socket

if Hammond cable is to be used, or a 6-contact

socket (furnished with the 3H kit) if the Leslie

727 cable assembly is used. (If the outlet box

is already equipped with asecond 5-contact

socket, use of the 727-5 Adapter makes it

possible to attach the 6-pole plug of the Leslie

727 cable assembly.

)

b. If the outlet box method of connection is not

used, the speaker cable may be fed into the

generator compartment through asmall notch

that can be made in the bottom shelf of the

console. In this method, the 3M-1 cable is

recommended for use. The 3M-1 is a30-foot

assembly, complete with the necessary con-

nectors. For cable lengths other than 30 feet,

bulk cable should be used. The needed con-

nectors (6-contact socket and spade lugs) are

regularly included in the 3H Echo Control kit,

Complete the remaining connections for the Echc

Control installation according to the diagram be-

low;

TREMOLO

CONTROL

FIGURE 1

MATCHI.

COLORS C^W^-DRED

BLACK

Ll_

CL.

rn NO

OCO

q: I

<LU

o£3

cc i

TWIST

CONNECT TO G-G TERMINALS ON PREAMP

FTREMOLO CONTROL IS NOT INSTALLED

MAIN \\

3H TERMINAL BOX

TWIST-

OUTLET BOX INSTALLATION

SEE PARAGRAPH "A"

NOT SUPPLIED \

INSULATING SLEEVES

NOT INSTALLED ON

ALTERNATE INSTALLATION

6X4*

7PIN

|AC 14

3CO

GND

CONSOLE PREAMP TERMINAL STRIP

ALTERNATE INSTALLATION USING 3IVH CABLE

SEE PARAGRAPH "8"

GRAY

AC BLUE

YELLOW

GND N.C. 2I

TO ECHO SPEAKER

RED BLACK

SIG. SIC

SOCKET

BACK VIEW

WIRE NUTS

HOLD WIRE ENDS PARALLEL AND TOGETHER BUT DO NOT TWIST-

WHILE PUSHING WIRES FIRMLY INTO MOUTH OF NUT.SCREW ON"

WIRE. NUT.

Special Handling of DC Tremolo Control Voltage

The installation shown in Fig. 1introduces the DC

tremolo control voltage at apoint in the circuit which

causes it to be present in both the Main and the

Echo speaker channels. For this type of installation

it is generally assumed that only the current model

Leslie Speakers will be used in the installation. How-

ever, in those installations where the speaker or

speakers on one of the channels are either Hammond

tone cabinets, or early Leslies, or both, the Tremolo

Control should be installed in adifferent manner.

Since it is desirable to keep the DC tremolo control

voltage out of the channel which includes Hammond

tone cabinets and/or early Leslies, the Tremolo Con-

trol should be connected into the circuit following the

Echo Control, as shown in the installation sketch be-

low. This particular arrangement assumes that the

current model Leslie Speakers will be connected to the

Echo channel, whereas the early Leslie Speakers

and/or any Hammond tone cabinets will be connected

to the Main channel. 7n this tony the Type 2Adapter

need not be used. However, if for any reason it be-

comes necessary to use earlv Leslie Speakers or

Hammond tone cabinets on the Echo channel, the

tremolo control voltage must be isolated through the

use of aType 2Adapter. The Type 2Adapter, when

used, is connected to the amplifier which is to be

isolated from the DC control voltage, the connection

being made at the plug which would otherwise receive

the cable from the console. This cable then plugs into

the Type 2Adapter. (Sec "Early Model ^Leslie

Speakers", page 9.)

FIGURE 2

TREMOLO

C0NTR0L

MATCH

COLORS

STRIP

ALTERNATE INSTALLATION USING >3M-

SEE PARAGRAPH "B" ON PAGE CABLE

GRAY

AC BLUE

YELLOW

GND. 3I

RED BLACK

SIG. SIG.

SOCKET

BACK VIEW

TO ECHO SPEAKER

WIRE NUTS

HOLD WIRE ENDS PARALLEL AND TOGETHER BUT 00 NOT TWIST-

WHILE PUSHING WIRES FIRMLY INTO MOUTH OF NUT, SCREW ON

WIRE NUT.

Multiple Tremolo Control

Tremolo for two Leslie Speakers, or for two groups

of Leslie Speakers, may be controlled independently

by the use of two tremolo controls, connected as

shown in the diagram below. Since both these con-

trols are the Tremolo Controls, the DC tremolo con-

trol voltage will be present in both the Echo and

the Main channels. As noted previously, the Type 2

Adapter must be used to isolate this DC tremolo con-

trol voltage from any early model Leslie Speakers or

early Hammond tone cabinets that may be used in

either channel. Hammond tone cabinets, series PR

and later, may not be used in this type installation.

When early model Leslie Speakers are used in an

installation and it is desirable to control the tremulant

on these units, a228 Tremolo Control must be used.

This control may be obtained from Electro Music,

together with complete instructions for its installation.

TREMOLO

CONTROL

"ECH0'J

FIGURE 3

ALTERNATE INSTALLATION USING 3M-I CABLE

SEE PARAGRAPH "0* QN PAGE II

GRAY

AG BLUE

YELLOW

GND NC 2I

QC viri

JLU

TO ECHO SPEAKER

RED

SfG BLACK

SIG

iSOCKET

IBACK VIEW

*WIRE NUTS

HOLD WIRE ENDS PARALLEL AND TOGETHER BUT DO NOT TWIST.

WHILE PUSHING WIRES FIRMLY INTO MOUTH OF NUT SCREW ON

WIRE NUT.

GENERAL GUIDE FOR MULTIPLE SPEAKER INSTALLATIONS

KEY TO ACCESSORY ANO CONNECTOR

2A- TYPE 2ADAPTER

5A- LESLIE POWER RELAY

5P- PLUG ,5 POLE

DESIGNATIONS

5S-SOCKET, 5POLE

6S- SOCKET, 6POLE

SLIE -SERIAL BELOW 52(

LESLIE "SER IA LABOVE 52(

(INCLUDES 21 HANO

LATE 31 H)

NTHIS INSTALLATION TREMOLO IN THE

EARLY LESLIE OPERATES CONTINUOUSLY

117 VAC 117 VAC

CONSOLE CURRENT

LESLIE

6EARLY

LESLIE

ORIGINAL CABLE

—

HAMMOND

H,HR AND

EARLIER SER-

IES ONLY

=Wi

WITH CONSOLE TO ADDITIONAL SPEAKER

ECHO TREM.

3H 426

NOTE; USE FIG ICONNECTION WHEN MAIN SPEAKER IS CURRENT LESLIE. TREMOLO WILL 8E FULLY CONTROLLED

USE FIG.2 CONNECTION WHEN MAIN SPEAKER IS EARLY LESLIE OR HAMMOND. TREMOLO IN EARLY LESLIE

WILL OPERATE CONTINUOUSLY.

ECHO SPEAKER

CURRENT

LESLIE

7VAC MAIN SPEAKER

TO ADDITIONAL SPEAKER

ORIGINAL CABLE WITH CONSOLE TO ADDITIONAL SPEAKER

ECHO

3H TREM.

428 TREM.

428

SEE FIG. 3

ECHO SPEAKER

CONSOLE CURRENT

LESLIE

17 VAC MAIN SPEAKER

TO ADDITIONAL SPEAKER J)

ORIGINAL CABLE WITH CONSOLE TO ADDITIONAL SPEAKER *0

ECHO

3H TREM

228 TREM

426 SEE FIG, 2. ALSO INSTALLATION INSTRUCTIONS SUPPLIED WITH 228 CONTROL

CONSOLE

7VAC 117 VAC

CURRENT

LESLIE

ECHO SPEAKERS

1EARLY

LESLIE

HAMMOND

ta 5AJs>, m*

117 VAC

ADDITIONAL

SPEAKER

MAIN SPEAKERS

EARLY

LESLIE

HAMMOND

TO ADDITIONAL SPEAKER

5POLE SOCKET "TO 6POLE PLUG ADAPTER REQUIRED ON SOME 31H LESLIES ORIGINAL CABLE WITH CONSOLE

*See Amplifier Schematic on page 23 for 22H Cabinets below Serial 22750, 22R Cabinets below 40900,

TYPE 3M ECHO COfNTROL

(3M KIT)

TO VOICE COIl >

TERMINALS RED

CW AMfLlFlEft >

rO 4MAIN

EN5EM&LE

ECHO

TO TYP£ 2

TREMOLO CONTROL

ECHO SPEAKtA

CABLE

TO CONSOLE

SPEAKER YELLOW

VOICE COIL 5>

CONNECT BLACK WIRE (GROUND )AS SHOWN IH

MODEL MINSTALLATION 01ASRAN ON PAGE 2

TYPE 3H ECHO CONTROL

(3H AND A-IOO KITS

)

I—

MAIN

ENSEMBLE

ECHO

RED

MAIN

SPKR.CA&U

BLAC\

BED

ECHO

SPKft. CABLE

>BLACK

TO PREAMP OR TREMOLO CONTROL

423 TREMOLO CONTROL

6X4

ADAPTER FOR USE

WITH CONSOLE

RECTIFIER

6X5

DC tt£T MoJl

TO ORGAN PREAMP

G6 TERMINALS

,i:i

isolation

TRANSE

TREMOLO

SWITCH

EXTERNAL

SPEAKER

CABLE

TO GROUND

TYPE 2ADAPTER

SERVICING AND TECHNICAL

INFORMATION

ON COMPLETE LESLIE SPEAKER CABINET

Replacement Parts for Servicing

Replacement transformers, filter chokes, and tremolo

relays, should be obtained from the Electro Music

factory. Standard type parts such as rubes, fuses,

sockets, resistors, and condensers, can be obtained

from radio parts supply stores. The detailed parts list

with this manual will give full parts replacement

information.

AMPLIFIER AND ELECTRICAL

Amplifier is removed from cabinet by taking out

the one screw that holds the front end of the amplifier

to the bottom of the cabinet. After the two motor plugs

and speaker plugs are removed, the amplifier may be

withdrawn. When pushing the amplifier back into

place, align the back end of the chassis in approxi-

mate position so that the amplifier guide and hold-

down clamp will engage the amplifier.

Fuse

The amplifier uses areplaceable Slo Bio V/

2amp.

fuse to protect the power supply against most short

circuits. Before replacing ablown fuse, determine the

cause of fuse failure. Do not substitute afuse having

ahigher current rating than that specified.

Screen Voltage Regulation on Power Tubes

This amplifier uses anew and relatively simple regu-

lating circuit to hold the output tubes screens at the

best operating voltage regardless of signal level varia-

tions. The result is maximum efficiency in getting the

greatest useful power output for the total power con-

sumed.

Gas regulator tubes will maintain aconstant voltage

drop regardless of current variations, within rated lim-

its. By proper choice of gas tube relative to the power

supply voltage, aclosely held voltage is made avail-

able for the screens. Parts used and functions are as

follows:

1. 0C3-VR105 Regulator tube provides constant volt-

age reduction in aseries circuit to the output tubes

screens.

2. 470 ohms 1/2 watt resistor—not critical in value.

Acts to suppress possible gas tube oscillations

caused by screen current variations. It also acts as

afuse in case of accidental screen circuit short.

Tremolo Control Malfunctions

Non-operation of the Leslie tremulant can be cor-

rected by checking the following:

1. Make sure the tremolo control is wired into the

circuit exactly as shown in the diagram for the

type installation which is being made.

2. Check the connecting cable for shorts or other con-

ditions which would alter the DC voltage super-

imposed on the signal line. It should be approxi-

mately 100 volts.

3. If anon-Leslie speaker selector (Echo) switch or

Hammond cabinet is included in the hook-up,

make certain the echo switch or cabinet connection

doesn't cause the superimposed DC voltage to be

grounded out.

4. Should none of the above reveal the non-operation

cause, then adetailed check of the Leslie tremolo

circuit components both in the console and Leslie

amplifier should be made against the wiring dia-

grams in this manual.

Operation of the Tremolo Control

The (428) tremolo control circuit superimposes a

DC controlling voltage on the signal line to the speak-

er cabinets. This is used to actuate atube operated

relay circuit for turning power on and off to the

tremulant motors without need of control wires from

the console to the speaker cabinets.

The tremolo control box installed at the console has

aDC isolation transformer in the signal line. Without

affecting the organ generator or amplifier circuits in

any way, apositive voltage can be applied to the

speaker signal line at the transformer center tap. A

10 mfd. condenser at the center tap puts the signal

line at low audio impedance to ground, and yet allows

changes in DC potential.

The relay control tube is one triode of a12AU7.

This triode has the relay coil and acurrent limiting

resistor in its plate circuit. The cathode is connected

to the cathodes of the output tubes and so is about 25

or more volts above ground. With the grid at ground

potential, this cathode potential cuts off the plate cur-

rent flow. With aDC potential on the signal line

greater than the biasing 25 volts, the grid is raised up

to the cathode potential and the triode draws plate

current to operate the relay.

The triode control grid has aone megohm isolating

resistor. This resistor prevents the grid from being

driven positive with respect to cathode, and also pre-

vents any effect on the operation of the audio on the

signal line. Because the resistor also acts as alimiter,

the DC control voltage is not critical and allows cir-

cuit operation over wide variations in B+ and AC

line voltages.

The furnished tube adapters used to obtain the con-

trolling voltage from the organ amplifier, have internal

dropping resistors which protect the power supply in

case of an accidental short circuit.

Distortion

Distorted sound is often caused by atoo high set-

ting of the Leslie volume control. Amplifier gain is

purposely greater than necessary, so low output con-

soles can still provide full sound power output from

the Leslie. Arbitrary setting of this volume control at

maximum will surely result in distortion when the or-

gan sw^ell control is fully opened. Instructions for

properly setting the volume control are given in an

earlier section of the manual.

Brilliance of Sound

Avariation in high frequency output from the Leslie

can be arranged. The amplifier includes a.001 mfd.

capacitor from grid to grid of the balanced input

stage. By changing the value of this capacitor, varia-

tions in brilliance of tone can be obtained

To increase brilliance, change the value to about

500 mmfd. or less. To decrease brilliance, shunt addi-

tional capacity across existing capacitor, or replace

with agreater value to obtain desired balance. Do

not change the output transformer primary shunting

condensers.

Voltage Readings

If the amplifier develops difficulties resulting in mal-

function or non-operaton that is not remedied by

tube or electrolytic condenser replacements, the vari-

ous voltages should be measured and compared to the

voltages shown on the circuit diagram. The voltages

indicated were measured with a20,000 ohms per volt

voltmeter, and differences in meter resistance and line

voltage variations as well as parts tolerances should

be kept in mind. If any abnormally high or low volt-

age is noted, it usually indicates adefective part in

the associated circuit.

Transformer Replacement

If the output transformer is replaced, the two plate

leads should be as short as possible and lie close to

the chassis.

Electrolytic Condensers

Practically all modern amplifiers contain electrolytic

condensers. These have adefinite life expectancy, and

must eventually be replaced. The Leslie amplifiers use

the finest electrolytic condensers obtainable, and ex-

perience has shown that many years of trouble free

service can be expected.

In view of the fact that they will eventually wear

our, most of the electrolytic condenser units on the am-

plifier^ are contained in asingle plug-in unit that can

be replaced as easily as a tube. The condenser is a

four section 30-30-30-10 mfd. 475 volt unit.

Tubes

Tubes are acommon source of amplifier difficulties,

although it must be recognized that certain mal-

functions which might at first appear to be caused by

tubes, are actually the result of other conditions.

Checking in atube tester will reveal certain tubes

to be defective. However, replacement is also recom-

mended for tubes which have been in service for a

considerable period of time, as their performance will

have deteriorated and the amplifier will not operate

efficientlv.

Tubes for replacement purposes may be obtained

from alocal source. However, for best operating re-

sults it is recommended that the 6550 power tubes

be replaced as apair, with units obtained from

Electro Music, These tube pairs have been carefully

tested and matched for use in the Leslie Speaker.

Line Voltage

Exceptionally low or high line voltage may cause

difficulties with amplifier operation. If the line voltage

falls below 100 volts, unsatisfactory performance will

result. Low line voltage can be caused by poor con-

tacts in the cable wiring or exceptionally long cable.

Adding the Leslie 5A relay is an easy way to overcome

low line voltage due to long cable.

Electric Brake

When the tremolo control switch is in off position,

braking of the tremulant motors is obtained by having

the control relay apply adirect current to the motors.

During the off time, the direct current flows through

the motors continually. No harm is done because the

current is substantially below normal running ratings.

The DC braking voltage is obtained through afull-

wave rectifier circuit in the primary of the power

transformer. Components and functions are as follows:

1. Silicon diode rectifier (two used)

2, 100 ohm, 3watt resistor

3, ,1 mfd, 400 volt filter condenser

4. Suppressor coil—prevents switching clicks

in speaker.

In the case of 22H cabinets with serial numbers

below 22750 and 22R cabinets with serial numbers be-

low 40900, asomewhat different brake circuitry will be

found. In these units the DC braking voltage is

obtained by means of rectifying and filtering a25 volt

tap on the power transformer primary. The com-

ponents used, and their functions, are as follows:

1. Silicon diode rectifier

2. 200 mfd, 50 volt filter condenser

3. 3ohm limiting resistor—protects silicon diode

rectifier from current surges

4. Suppressor coil—prevents switching clicks in

speaker.

LOUDSPEAKER SYSTEM AND DIVIDING NETWORK

The Leslie uses afull two way system with two

separate speakers. Pedal and midrangc tones are gen-

erated by aheavy duty 15 inch speaker with perma-

nent magnet. Its nominal impedance is 16 ohms.

Upper middle and highest tones are generated by a

compression sound chamber driver unit also using

permanent magnet. Its nominal impedance is 16 ohms.

The 15 inch speaker is mounted in amatched bass

reflex enclosure. It is therefore important that the cabi-

net back is in place and securely fastened. The high

frequency driver is loaded by means of arotary horn.

Only one of the horns in the upper rotor radiates

sound. The other horn dynamically balances the as-

sembly to eliminate vibration. Asmall cotton acoustic

filter is placed in the throat of the horn. It also pre-

vents dust from entering the driver unit. Do not re-

move this filter.

The two specialized range speakers are connected to

the amplifier via atwo half section Mderived fre-

quency dividing network (crossover). This network

electrically separates the bass and treble range output

of the amplifier, and directs the proper signal to each

speaker. The nominal separation occurs at 800 cps.

The impedances used in the loudspeaker system allow

adividing network design of extremely rugged and

electrically stable parts. It is very unlikely that trouble

will ever be experienced with this clement.

Speaker Problems

Because of the extremely strong permanent mag-

netic fields with both speakers, it is inadvisable to

attempt cone replacements or repairs involving dis-

assembly. The Electro Music factory will either repair

afaulty unit or supply areplacement.

Should the treble speaker become inoperative for

some reason, emergency operation of the cabinet can

be arranged. Unplug the bass speaker from the divid-

ing network and plug it direct to the amplifier output

socket. There will, of course, be alack in musical

quality until the complete system is restored.

Suspected low output from the dividing network

output can be checked by the same procedure as

above.

MECHANICAL MAINTENANCE

Motor

After several years of typical service, or areason-

ably long period in commercial use, the motors might

accumulate lint and dust. This accumulation interferes

with proper ventilation and oiling. Time invested in

cleaning the motors is well repaid by longer life. The

motors can be removed easily and cleaned with cleans-

ing solvent.

Upper Motor Removal and Replacement

Remove the motor power plug from socket, and

remove the two wing nuts. Then the motor can be

removed from the cabinet, IMPORTANT: The upper

motor must run counterclockwise when viewed from

the top or pulley end. Otherwise, the upper tremulant

rotor will not come up to speed. If the motor is dis-

assembled or another motor substituted, the rotation

should be checked to be sure it is counter-clockwise.

Lower Motor Removal and Replacement

Remove the motor power plug from the amplifier

socket and remove the two wing nuts that hold it to

the shelf. The motor will drop down for removal.

When replacing this motor, first position the belt on

the motor pulley before it is lifted into place onto the

mounting screws. Because the front wing nut controls

the tremulant drive belt tension, this must be adjusted

whenever the motor is replaced. See "Belt Tension

Adjustment" below.

Disassembly and Cleaning

For cleaning purposes, before a motor can be com-

pletely taken apart, the pulley, pulley support ring,

and oil tube assembly must be removed. When remov-

ing the end covers, be sure to note or mark the posi-

tion of the bottom end cover with respect to the lami-

nations. If this should be rotated relative to its original

position, bearing misalignment will result and the

motor will be noisy or even bind.

After reassembly, if there is some noise during mo-

tor operation, it's probably due to temporary bearing

unseating. Alight tap with afairly heavy tool on the

laminations side will shake the assembly into proper

position.

The mounting brackets used with the motors are

adjusted to obtain 5%" between centers of mounting

holes. If the brackets are bent, they should be straight-

ened to obtain this dimension. Upper and lower

motors are interchangeable if the proper pulley is

used. Motor pulley is held on to the shaft by the

center screw, and after this is removed, the pulley

may be pulled from the shaft. The metal three groove

pulley is for upper rotor and the single groove pulley

-is for lower rotor use.

Belt Replacement

For average service, the belts usually last several

years. In the event of any excessive belt wear, the

pulley and mountings should be examined for rough

surfaces or misalignment that might cause the wear,

Upper Belt Replacement

Remove the upper compartment cover and pre-

stretch the new belt by pulling it out to full length.

Place it over one horn and then the other alternately;

then on desired motor pulley groove and idler pulley.

Three tremulant speeds are available by choosing

one of the three grooves on the motor pulley. Center

groove provides standard tremolo, upper groove a

slow tremolo, and lower groove afast tremolo.

Lower Belt Replacement

Afrayed or worn lower belt can cause noise by

striking the lower shelf or belt guard and should be

replaced as follows: Remove the large center back and

lower compartment cover. Along the rim of the bass

speaker, remove the eight mounting screws. Remove

the connecting cable plug from the dividing network.

The bass speaker can now be lifted from the shelf and

out of the cabinet. To avoid possible cone damage, lift

straight up for ashort distance.

Pull the exposed rotor support from shaft. Place the

new belt on the large pulley and pass the rest of the

belt between the rotor and shelf towards the driving

motor.

Remove the (motor-holding) wing nut nearest the

cabinet back to partially drop the motor. Temporarily,

hook the new belt over the screw that had the wing

nut.

Replace the bearing support on the rotor shaft and

position the ends in the shallow locating channels at

the speaker opening hole. Align the holes in the sup-

port with the speaker mounting holes in the locating

channels.

Place the bass speaker back in position and install

the two screws that hold the speaker at each end of

bearing support. These screws should be just started

in position and then the other six screws started. After

all eight screws are in position, they may be tightened.

Place the new belt on the driving motor pulley and

put the motor back in position using the original hold-

ing wing nut.

Belt Tension Adjustment

Adjust the belt tension by first loosening the front

motor wing nut only, and pulling the motor assembly

to the left until the belt is stretched. Release the as-

sembly and the belt will assume its proper tension.

Tighten the wing nut with the motor at this position.

Do not stretch the belt tight and set the adjustment

at this maximum tension, as noise and hard starting

will result. Acorrectly adjusted belt will slip some

as the rotor first starts turning. This, however, is

anormal situation, and the slippage disappears after

the first few seconds' operation.

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