Toa KD-3 Operating Instructions Manual

Operating Instruction Manual

ELECTRONIC MUSIC AMPLIFICATION SYSTEM

Model KD-3

TOA Corporation

KOBE, JAPAN

Contents

Precautions

General Description

Features

Front Panel: Names of components & their usage

Rear Panel: Names of components & their usage

Block and Level Diagrams

Specifications

Appearance ...

Precautions

1

2

2

3

4

5

5~6

6

1. Power Supply

The KD-3 is designed to operate on local AC (50/60Hz) Mains, ±10%.

2. XLR Type Audio Connector

The connectors are wired as follows.
The pin 1 is ground (shield), the pin 2 cold (low, minus), the pin 3 hot (high, plus).

3. Phantom Power Supply

The phantom power switch on channel 1 input permits the user to supply 48V DC
through the input connector to a condenser microphone. If phantom power is not
required, the switch must be in the "off' position.

4. Description of components and functions of the KD-3

Various descriptions are applied, depending on each manufacturer. In our
Operating and Instruction. Manual explanation of components and functions is
made according to TOA's usage for them.

— 1 —

General Description

The TOA KD-3 is a complete electronic music amplification system in a single

portable package, consisting of a stereo mixer, spring reverberation unit, graphic

equalizer, power amplifier, and two-way speaker system.

The mixer section provides four input channels. Each input features 2-band active EQ,

an independent effects send, a clip LED indicator, a direct output, and a channel level

control with concentric balance control. Channel 1 features an electronically balanced
XLR mic input connector with switchable 48 volt phantom power, for use with
condenser-type microphones, and each input channel features input sensitivity

switches. In addition, channel four features an RIAA equalized phono input for direct

connection of magnetic cartridge turntables.

The master section contains an effects patching loop with crossfade and level controls,

5-band EQ stereo L&R controls, and a stereo headphone monitoring system.

The 220 watt RMS internal power amplifier features Auto Comp compression

circuitry, with an LED indicator, to ensure distortion-free performance and protection

for the internal speaker system. The two-way speaker system utilizes a heavy duty

15-inch woofer and a constant directivity horn with piezo electric driver.

The KD-3 is covered in a durable and attractive high tech gray vinyl fabric.

Features

System Features

Four input channels

•

220 watts/4-ohm, 150 watts/8-ohm power amplifier output

•

Auto Comp compression circuitry w/indicator

•

Power amplifier protection circuitry w/indicator

•

Built-in, heavy-duty two-way loudspeaker system of 15"(38cm) woofer and constant

•

directivity horn with piezo driver

Built-in spring reverberation unit

•

MIDI Thru circuitry

•

Each Input Channel

Two band EQ

•

Independent effect send is post-EQ/post-fader

•

Direct output on each channel, ideal for recording

•

Concentric balance control and channel volume control

•

LED clip indicator for best signal to noise ratio

•

Individual Input Level Selector switches

•

Input Channel 1 has electronically balanced XLR microphone input connector with

•

switchable 48 volt phantom power

Input Channel 4 has stereo phono (RIAA) inputs for turntable with magnetic

•

cartridge

Master Section

Stereo Left and Right outputs with both RCA and 1/4" phone jacks

•

Level and crossfade control for returning effects signals to stereo mixing busses

•

Two band EQ for internal reverberation unit

•

Headphone monitoring for Stereo L and R, SUM and EFF

•

Five band graphic equalizer w/bypass switch

•

Complete patch bay

•

— 2 —

Effect Control [EFF]

This control determines the
amount of post-fader/post-EQ sig­nal assigned to t he effect buss
from a given input channel, and
thus the level of effects for that
channel.

Clip LED Indicator [CLIP]

The LED indicator lights when
the pre or post EQ signal level
reaches 3dB below clipping, giv­ing a visual reference for opti­mum setting of the level control.
Under normal usage, the cl ip
LED's should only flash intermit­tently. A constant or steady LED
indicates that t he input level con­trol setting is too high, and
should be reduced.

Low Equalizer Control [LOW]

The low EQ control alters the low
frequency response of th e input
channel, providing ±15dB at

20Hz of continuously variable ac­tive shelving equalization. The
"0" detented position provides
flat audio response. Please no te
that excessive boosting of low
frequencies may cause th e input
clip LED to light. Under these
circumstances, it may be neces­sary to lower the input level

control in order to maintain prop­er headroom an d minimize dis­tortion.

High Equalizer Control [HIGH]

The hig h EQ control alters t he

high frequency response of the
input channel, providing ±15dB

at 20kHz of continuously variable
active shelving equalization. The
"0" detented position provides
flat audio response.

Balance Control [BAL]

This control adjusts the level ba­lance of the channel input signal
fed to the Stereo Left and Right
mixi ng busses.

Input Channel Level [LEVEL]

The level control provides con­tinuously variable adjustment of
the channel output to the Stereo
Left and Right mixing busses,
thus d etermin ing the level of the
channel in the main sound sys­tem mix. The nominal level of the
input level control is at the "0"
dB position.

Graphic Equalizer In/Out Switc h

[IN/OUT ]

The in/out switch enables com­parison between a flat response
(OUT) an d th e equalized re­sponse (IN ). The "out" position
completely removes the equalizer
from the KD-3 circuitry.

Graphic Equalizer Control
[GRAPHIC EQUALIZATION]

The graphic equalizer is 5 inde­pendent active bands (filter), pro­viding 15dB of boost or cu t at
each center frequency. The "0"
detented position provides flat
audio response.

Internal Reverb Equalizer-

Control [REV EQ HIGH/LOW]
These controls alter the frequency
response of the b uilt-in reverb
circuitry. The "0" detented posi­tion of both controls provide flat
audio response.

Cross-fade Control fo r Reverb
and Effect [REV/EFF X-FD]

When this control is in the center
position, the reverb signal (thus
the internal reverberation unit)
and EFF RET signals are equally
assigned t o th e Stereo m ixing
buss. Rotating the control
counter-clockwise decreases t he
EFF RET signal level, keeping the
original level of the reverb signal.
Rotating the control clockwise
decreases the reverb signal level,
keeping the original level of the
EFF RET signal.

Level Control for Reverb/Effec t

[REV/EFF LEVEL]

This control governs the amount
of reverb signal through the rever­beration unit (built in), and effect
signal returned through the effect
return jack (EFF RET) to the
stereo mixing buss. The signals of

reverb signal and EFF RET are
controlled simultaneously.

System Level Control
[SYSTEM LEVEL]

This control determines the over­all level of the KD-3 system.

Stereo Level Control
[STEREO LEVEL]

These concentric controls deter­mine the overall level of the
Stereo Left and Right output
(STEREO OUT L, R).

Aux Input Level Control

[AUXIN]

These concentric controls govern
the amount of Aux signals to
Stereo Left an d Right through the
Aux In jacks (AUX IN L, R).

Headphone Selector, Leve l
Control, and Ja ck [PHONES)

An outpu t jack, level control, and
3-position rotary switch are pro­vided for the use of headphones.
Any one of three signals can be
monitored through headphones
using the selector switch:
STEREO, SUM, or EFF. Al l moni­tored signals are in mono with the
exception of Stereo Left and Ri ght

which are monitored, of course,
in stereo. The level control ad­justs the volume of the head­phones, and the headphone jack
will accept a ny stereo head­phones with an impedance of 8
ohms or higher.

Clip LED Indicator [CLIP]

The Stereo and Sum cli p indica­tors light when their respective
signals reach 3dB below clipping,
giving a visual indication before
the onset of distortion.

Sum Pro/Post Select Switc h
[SUM SELECT]

The mono Sum (System) signal is
derived by summing the Stereo
Left and Ri ght signals. The Su m
Select switch determines whether
this summing occurs before or
after the Master Stereo faders.
When using the switch in the
Pre-position, the Sum (System)
outp ut level is indep endent of the
Master Stereo Le ft and Right level
controls. In the post-position, ad­justing the Master Stereo Left and
Right level controls will affect the
volume of the Sum (System) out-

put.

Power/Protect LED

Indicato

r

[POWER/PROTECT]

The LED indicator lights red and

remains lit for 3 seconds after the
power switch has been turned on,

and then turns to green when the

KD-3 is powered up. The LED
lights red when the p rotection
circuit is activated.

Power Amp Compressio n

Indicator [COMP]

The Comp LE D l ights when th e
internal compressor is activated.
The compressor is provided to

protect t he speaker system by

compressing the input signal

level of the power amplifier when

clipping occurs in the output

stage. Frequent flashing of the

LED is not reason for alarm.

However, a constant or steady

light indicates that the KD-3 is

being overdriven and that the

internal power amplifier is poss-

ibly "under powered" for that

particular application. The out-

put level of the KD-3 should be

decreased unt il the LED only

flashes intermittently.

MIDI LED Indicator [MIDI IN]

This LED indicates the presence

of MIDI data at the MIDI input

connector on the rear panel (M-

IDI

IN).

Stereo L&R Output Jack

[STEREO OUT L/R)

The unbalanced RCA pin jacks
and 1/4" phone jacks are wired in
parallel. The RCA pi n jack has a
nominal output level of —l0 dB
and an impedance of 1k ohms,
and the 1/4" phone jack has a
nominal output level of +4dB
and an impedance of 1k ohms.
All jacks may be used simul­taneously.

Graphic Equalizer Output Jack

[GEQ OUT]

This jack allows the KD-3 and the
internal graphic equalizer to be
used with an external power
amplifier, or in conjunction with
the GEQ in jack, to be used inde­pendently of all other KD-3 cir­cuitry. Nominal output level is
+4dB with an impedance of 1k
ohms.

Power Amplifier Input Jack-

[POWER IN]

The Power Amp Input jack allows
the internal power amplifier to be
used with external equipment.
When a plug is inserted, the
power amplifier is automatically
disconnected from the KD-3 mix­er section. The nominal input
level is +4dB with an input impe­dance of 10k ohms.

MIDI Input Connector [MIDI IN]

This connector w ill accept the
MIDI output of any synthesizer,
sequencer, or other M ID I device.
Use of non-MIDI-standard DIN
cables, or of cables longer tha n
5m (16ft.) may result in i mproper
operation and data loss.

AC Power Cord-

The power" cord is of the three­wire type with proper grounding
facilities built-in. (6ft.)
Caution — The ground pin
should not be removed under any
circumstances. If the KD-3 m ust
be used without proper ground­ing facilities, a suitable grounding
adapter should be utilized. Op­eration of the KD-3 with proper
grounding techniques will result
in less system noise and greatly
reduced shock hazard.

Graphic Equalizer Input Jack
[GEQ

IN ]

The GEQ input jack allows the
graphic equalizer to be used inde­pendently of the KD-3 with other
external equipment, or the inter­nal power amplifier and the
graphic equalizer with external
equipment. When a plug is in­serted, the main mix from the
system buss is disconnected from
the graphic equalizer and th e
power amplifier. The nominal in­put level is +4d B w ith an in put
impedance of 10k ohms.

MIDI Thru Connectors
[MIDI THRU]

The MIDI signal from the MIDI
Input connector (MIDI IN) is split
and sent unaltered to the four
MIDI Thru connects on the KD-3,
if used. Each of the MIDI Thru
connectors can be connected a
different synthesizer's MIDI Input
connectors, allowing one MIDI
keyboard or sequencer to control
up to four other MIDI devices.

RCA Phono (RIAA) Input

[PHONO]

These RCA pi n jacks have a
nominal level of -55dB and an
impedance of 50k ohms, and in­clude RIAA phono equalization.

Input Level/Sourc e Selector

[PAD]

When using the RCA Phono In­puts, select th e "PHONO" posi­tion of this switch.

Earth Terminal [GND]

This terminal can be used to
ground other devices su ch as tap e
decks and turntables to the KD-3
to reduce hu m and shock hazard.

Effect Send Jack [EFF SEND]

This 1/4" phone jack is used in
conjunction with the Effect Re­turn jack to connect an outboard
effects device (i.e. delay or re­verb) to the KD-3. The Effect Send
jack should be connected to th e
input of the Effect. Nomi nal out­put level is -10dB w ith an impe­dance of 1k ohms.

Effect Return Jack [EFF RET]

This 1/4" phone jack is used in
conjunction with the Effect Send
jack to connect an outboard
effects device (i.e, delay or re­verb) to the KD-3. The Effect
Return jack should be connected
to the output of the effect. Nomin­al input level is —20dB with an
impedance of 10k ohms.

AC Fuse

Warning : To avoid possible
equipment damage and/or per­sonnel injury, the fuse should
always be replaced with same
type and rating. Using improper
fuses wil l also void the warranty.
The KD-3 should always be dis­connected from AC outlet prior to
changing fuses. If fuse repeatedly
fails, the unit should be referred
to qualified personnel for repair.

Power Switch [POWER]

The power switch is a three­position type wi th the mid dle

position being the "off position.
The KD-3 should be operated in
the switch position which pro­duces the lowest amount of sys-

tem

hum.

Internal Speaker Input Jack
[INT. SP INPUT]

This jack is provided to drive the
KD-3's built-in speaker system
with an external power amplifier.
Its maxi mum program input pow­er capacity is 240 watts, with an
impedance of 8 ohms. When a
plug is inserted i n t he jack, the
built-in speaker system is auto­matically switched out of the KD­3's built-in amplifier.

Power Amplifie r Output Jack
[POWER AMP OUT]

The power output jack delivers
220 watts into a minimum 4-ohm
load, and is used to connect with
external speaker system.
Note: Do not connect to an exter­nal speaker system with less t han
8 ohms when the internal speaker
system is used simultaneously.

Aux Input Jack [AUX IN L/R]

The unbalanced 1/4" phone jack
have a nominal input level of

-20dB and an impedance of 10k
ohms.

Input Level Selector [PAD ]

The slide switch provides adjust­ment of the sensitivity of the 1/4"
Inpu t Jacks, and RCA pi n Input
Jacks, providing 30dB of attenua­tion at the "30dB" po sition. The
correct setting should be made
according to the output level of
the equipment connected.

Sum Output Jack [SUM OUT]

The Sum Output jack has a
nominal output level of +4dB
and an impedance of 1k ohms.

-1/4" Phone Channel Inp ut
[INPUT L/R]

These connectors arc unbalanced,

standard 1/4" phone jacks with an
input impedance of look ohms,
and an input level o f—30dB.
When a plug is inserted i nto the

1/4" input jack, the corresponding

XLR microphone input or RCA

pin (TAPE IN) channel input is

automatically switched out of the

input circuitry.

Note : Connect to "INPUT L"

when an instrument has a stereo
(Tip-Ring-Sleeve) output from a
single balanced 1/4" phone plug.
The instrument's Stereo Left and
Right channels are automatically
assigned to the Stereo Left and
Righ t busses, respectively.
Connect to both "INPUT L & R"
(2-cables) w hen on instrument
has a stereo output from t wo
unbalanced 1/4" phone plugs
(Tip-Sleeve). The instrument's
Stereo Left and R ight channels
are t hen assigned to the Stereo
Left and Right busses, respective-

ly.

Connect to "INPUT R" whe n the
instrument has a mono-output.
The mono signal will automati­cally be assigned to both Stereo
Left and Ri ght busses.

Phantom Power On/Off switch

[PHANTOM]

This switch alternately turns
"on" and "off the phantom pow­er (48V DC) for th e XLR connector

assigned to Chan nel 1. T his
switch should remain in the
"OFF" position when a mic­rophone requiring external power
is not connected.

Balanced XLR Microphone Input

[MIC]

The XLR-type microphone input
connector (channel 1 only) is
electronically balanced with a

nomi nal level of —6 0dB and an

input impedance of 1k ohms.

Phantom powering is provided

for use with condenser-type mic-

rophones (see PHANTOM). The

microphone input is automatical-

ly disconnected whe n either the

corresponding RCA Pin jack or

the 1/4" phone jack is used.

RCA Tape Input [TAPE IN L/R]

The RCA pin input jack is unba­lanced, with a nominal level of
— 30dD and an impedance of 100k
ohms.

Direct Output

[DIRECT OUT L/R]

The Direct Outputs on each chan­nel utilize an unbalanced RCA
pin jack with an impedance of 1k
ohms and a level of -10dB. T he
Direct Outputs are post-EQ/post­fader, and are useful both for
recording and for sending indi­vidual instruments to a main PA
mixer through direct boxes.

Front Panel

Rear Panel

— 3 —

— 4 —

Block and Level Diagrams

Specifications

MIXER SECTION

Frequency Response

+0, -3dB 20Hz to 20kHz (INPUT to STEREO OUT)

Total Harmonic Distortion

Less Than 0.03% +4dB* 1kHz (STEREO OUT)

Hum and Noise (STEREO OUT: Open 20Hz to 20kHz)

All Level Control M in im um —8 5dB

One INPUT Level Control Maximum —68dB

Equalization

LOW ±15dB 20Hz Shelving

HIGH ±15dB 20kHz Shelving

POWER AMPLIFIER SECTION

Power Output

150 watts minimum sine wave continuous average power output

monaural driving 8-ohms over a power band from 20Hz to 15kHz.

The maximum Total Harmonic Distortion (THD) at any power
level from 250 milliwatts to 150 watts shall be no more than 0.3%.
150 watts continuous average sine wave power into 8-ohm wi th
less than 0.02% THD at 1kHz.

220 watts minimum sine wave continuous average power output

monaural driving 4-ohm over a power band from 20Hz to 15kHz.

The maximum Total Harmonic Distortion (THD) at any power

level from 250 milliwatts to 220 watts shall be no no more than

0.3%.
220 watts continuous average sine wave power into 4-ohm with

less than 0.02% THD at 1kHz.

— 5 —

Frequency Response

+0dB, -1dB 20Hz to 20kHz

Total Harmonic Distortion

Less than 0.02% at 150 watts into 8-ohm at 1kH
Less than 0.02% at 220 watts into 4-ohm at 1kH

Hum and Noise

-67dB below rated output (IHF-A weighted)

SPEAKER SECTION

Speaker

15"(38cm) woofer, CD horn and piezo driver

Sensitivity

97 dB (1 watt 1 m et er ),

Frequency Response

70Hz to 20kHz

GENERAL SPECIFICATIONS

Power Consumption

450 watts maximum

Dimensions (WxHxD)

490mm x 719mm x 341mm

19¼"x28¼"xl33/8"

Weight

30kg (66.1 lbs)

z
z

Specifications

INPUT SPECIFICATIONS

Input

CHANNEL INPUT (L, R)
CH1~CH4

TAPE IN CH1~CH4

MIC CH1

PHONO CH4

AUX IN L,R

EFF RET

GEQ IN

PA IN

INT. SP INPUT

OUTPUT SPECIFICATIONS

Output

STEREO OUT (L ,-R)

SU M OU T

EFF SEND

PHONE S

DIRECT OUT (L.R)

GE Q OU T

POWER AMP OUT

Stereo phone jack is wired:

Tip=Left, Ring=Right, Sleave=Common.

The XLR type connector is electronically balanced.

Actual

Load

Impedance

Actual
Source

Impedance

1k

1k

1k

100

1k

1k

—

For Use

With

Nominal

For Use

With

Nominal

1k OR HIGHER IMP. LINES

1k OR HIGHER IMP. LINES

1k OR HIGHER IMP. LINES

8 O R HIGHER

1k OR HIGHER IMP. LINES

1k OR HIGHER IMP. LINES

8

The XLR type connector is wired as follows

PinNo.l-Ground
PinNo.2-Cold(Low)
Pin No.3-Hot (High)

Nominal

-30dB (24mV)

-30dB

(24mV)

-60dB (0.78mV)

-55dB (1.4mV)

-20dB (78mV)

-20dB (78mV)

+4dB (1.23V)

+4d B (1.23V)

—

Output Level

Nominal

+4dB (1.23V)

-l0d B

(245mV)

+4dB (1.23V)

-l0d B

(245mV)

+4d B (1.23V)

-l0d B

(245mV)

+4d B (1.23V)

(220W/4n)

Input Level

MAX. Before Clip

0dB (0.775V)

0dB (0.775V)

-30dB (24mV)

-25dB (44mV)

+ 10dB (2.45V)

+ 10dB (2. 45V )

+ 20dB (7.75V)

—

(240W)

0dB is referenced to 0.775V RMS.

MAX. Before Clip

+ 20dB (7.75V)

+ 6dB (1.5V)

+ 20dB (7.75V)

+ 20dB (7.75V)

+ 20dB (7.75V)

+ 20dB (7.75V)

+ 20dB (7.75V)

—

0dB is referenced to 0.775V RMS.

Specifications are subject to change without notice.

Connector

STEREO PHONE JACK
PHONE JACK

RCA PIN JACK

XLR-3-31 TYPE

RCA PIN JACK

PHONE JACK

PHONE JACK

PHONE JACK

PHONE JACK

PHONE JACK

Connector

PHONE JACK

RCA PIN JA CK

PHONE JACK

PHONE JACK

STEREO PHON E J ACK

RCA PIN JACK

PHONE JACK

PHONE JACK

Appearance

— 6 —

Printed in Taiwan

133-02-840-7A