Shure M63 AUDIO MASTER Techical Data

PRODUCTS

DATA

GENERAL

The Shure Model M63 AUDIO

MASTER@ is designed
to give maximum flexibility in the control of volume,
bass response, treble response, and high and low
frequency

rolloff. The Model M63 works ideally as a

Master Control Center when used in conjunction with

the Shure Model M68 series of microphone mixers.

The M63 provides a means to equalize sound sys­tems for correction of room acoustics, to reduce
feedback, to provide special sound effects, to reduce
stand and stage noise and for tape recording.

AUDIO MASTER features:

m

Five types of outputs

-600 ohms balanced line level

-High impedance, high level

-High impedance, microphone level

-Low impedance, microphone level, balanced

-Headphone jack for monitoring

=

Inputs for two driving sources

=

VU meter to monitor audio level

=

Continuously variable high-pass and low-pass
6 dB per octave filters

Bass and treble tone controls

SPECIFICATIONS

(At 120 volts ac, 60 Hz line voltage)
Frequency Response

-t2 dB, 20 to 20,000 Hz (all controls flat)

Voltage Gain (outputs terminated as noted, others

open; volume and level control max.)

Line Output: 38.5 dB (600-ohm load)

Aux. Output: 39.0 dB (47k load)

Hi-Imp. Mic. Output: -1.0 dB (33k load)
Lo-Imp. Mic. Output: -21.0 dB (150-ohm load)

Tone Controls

Bass:

+

14, - 19 dB at 100 Hz Typical

Treble: + 16, - 19 dB at 10k Hz Typical

Filters

Hi-Cut and Lo-Cut 6 dB per octave, continuously

variable -3 dB point
Noise Output (Line with 600-ohm load)

Volume Control min.:

76 dB below

+8 dBm, 20 Hz -20 kHz

81 dB below

+8 dBm, 300 Hz -20 kHz

Volume Control max.,

4.7k source:

68 dB below

+8 dBm, 20 Hz -20 kHz

71 dB below

+8 dBm, 300 Hz - 20 kHz

Distortion

Under 1% THD at

+8 dBm output

Clipping Level

+18

dBm (600-ohm load)

VU

Meter (Calibrated for 600-ohm line termination)

0 VU = +8 dBm

tl

dB fixed; or

0 VU = +4 dBm; output may be attenuated by

20 dB

Inputs

Two, mixing. Impedance 50k nominal. No amplifica­tion precedes VOLUME control, so that high-level
input signals cannot cause overloading.

Outputs

600-ohm line: Balanced and floating, 150 ohms

minimum load, 125 ohms actual internal imped­ance. Will operate with up to 100

mA dc through

transformer for driving telephone lines.

Auxiliary Hi-Imp.: Unbalanced,

4.7k internal imped­ance. For driving high-level, high impedance
inputs.

Microphone Hi-Imp.: Unbalanced,

I

k internal imped­ance. For driving medium-level high impedance
microphone inputs.

Microphone Lo-Imp.: Balanced, 0.5-ohm internal

impedance. For driving low-level 25- to 250-ohm
microphone inputs.

Headphone: Two-level, for 600- to 2,000-ohm head-

phones. Crystal headphones may be used.

Operating Voltage

AC Operation:

108-132 volts, at

50160 Hz

DC

Operation: 30 volts, 20 mA maximum drain for

+8 dBm output

Overall Dimensions

See Figure 2

Weight

1.4 kg (3

Ib 2 oz)

Operating Temperature

-7°C to 57°C (20" to 135°F)

Certifications

The M63 is Listed by Underwriters' Laboratories, Inc.
and is listed by Canadian Standards Association as
Certified.

Copyright 1981, Shure Brothers Inc.
27A8024 (Al)

Printed in

U.S.A.

CONTROLS, CONNECTIONS AND OPERATION

WARNING

To reduce the risk of fire or electric shock, do
not expose this appliance to rain or extreme
moisture.

1

INPUTS

The two high impedance inputs (phono jacks)
marked HlGH LEVEL INPUTS are designed to accept
high level signals from a microphone mixer (such as
the Shure M68, etc.), tape recorder, AM-FM tuner, or
output from a Shure Model

A68P Phonograph Pre-

amplifier (accessory).

To use with the Shure M68 Microphone Mixer
series, connect the AUX. HlGH LEVEL OUTPUT on
the mixer to the input of the M63 with a shielded
cable having a phono plug on each end. Set the
MASTER volume control on the mixer to approximately
6 and use the VOLUME control on the M63 to adjust
the overall level.

Although not specifically designed for use with the

Shure M67, it may be used in conjunction with the

M67 in the following manner: connect a shielded

single conductor cable with a

%"

phone plug on one

end and

a phono plug on the other from the head-

phone output of the M67 to the M63 input. To obtain

good volume control action from the M63, install a

180-ohm resistor from tip to sleeve in the phone plug
and use the M63 volume control to adjust the output

to the desired level.

OUTPUTS

Microphone

The receptacle marked MICROPHONE LEVEL OUT-

PUT is a dual impedance output selected by the

switch above the receptacle. This output is designed
to work into a balanced 25- to 250-ohm input, or, with
the MICROPHONE IMPEDANCE selector switch in the
Hi position, into an unbalanced high impedance mi­crophone input on an amplifier or tape recorder. The

receptacle is a professional three-pin audio con-

nector designed to mate with Cannon XL series,
Switchcraft A3 (Q.G.) series or equivalent connector.
See Figure

1

for output receptacle connections.

WELDD_

10

.

-

-

SHIELD

-

- -

- -

!T"-

e3

;

\------A/

\

I

,-------I

MIC. OUTPUT MIC. OUTPUT

HlGH IMPEDANCE

LOW IMPEDANCE

(BALANCED LINE)

MICROPHONE OUTPUT PLUG CONNECTION

FIGURE

1

Line

The line output (binding posts) is on the rear panel

and is designated 600 OHM BALANCED

LINE OUT-

PUT. These terminals are numbered

"3" and

"2"

and

are in

phase with correspondingly numbered pins in

the microphone output connector. The adjacent

ground terminal corresponds to pin 1. While the line

output may be used to drive lines of various imped-

ances (150 ohms or greater), the VU meter is cal­ibrated for use with a 600-ohm terminated line.

OVERALL DIMENSIONS

FIGURE

2

Auxiliary

The phono jack marked AUXILIARY HI IMP OUT­PUT is a high-impedance, high-level output designed
primarily to feed a power amplifier requiring

.5

to 2
volts, or the auxiliary or tuner input of an amplifier
or tape recorder.

NOTE: The microphone, line and auxiliary outputs

may be used simultaneously if desired, to
provide an isolated PA feed or to drive dif­ferent pieces of equipment.

Headphone output

The headphone output on the rear panel is desig-

nated HEADPHONES. A two-circuit phone jack is used

to provide a choice of level for different headphone

impedances. Normally, a single-circuit plug should be
used. If inserted only partially (to the first detent),
the available voltage is approximately 0.25 volts; the
second position will provide approximately 0.50 volts
across 1000-ohm headphones at

+4

dBm (0 VU) line
output. Crystal headphones may be used, but the level
will be the same in either jack position.

If stereo phones are used, the two-circuit plug may
be inserted completely (to second position) and the
output will appear in both phones.

VU METER

When the METER SENSITIVITY switch (on rear

panel) is on the

0 VU =8 dBm FIXED position, an

output of 8

dBm on the 600-ohm line output (loaded

with 600 ohms), reads

0 VU on the meter. When the

METER SENSITIVITY switch is in the

0 VU VARIABLE

position and the

0 VU LEVEL ADJUST control is

maximum (fully clockwise), an output of

4

dBm on the

600-ohm line output (loaded with 600 ohms) reads

0

VU on the meter; at minimum position of the 0 VU
LEVEL ADJUST, fully counterclockwise, an output of
approximately -20

dBm on the 600-ohm line output

(terminated in 600 ohms) reads

0 VU on the meter.

The variable position on the METER SENSITIVITY
switch allows the VU meter to read

0

VU for outputs

ranging from -20

dBm to

-I-

4

dBm (600-ohm line

terminated), by adjusting the

0 VU LEVEL ADJUST
(screwdriver adjustment on rear panel). To calibrate
the VU meter properly in applications where a level
other than the fixed level is needed, set the VOLUME
control on the M63 until the meter deflects to the

0

VU position on the

loudest

peaks, then adjust the
0 VU LEVEL ADJUST control for the desired output
signal level. The LEVEL ADJUST control attentuates
all outputs simultaneously (except HEADPHONES),
while the internal circuitry operates at the proper
level to insure good signal-to-noise ratio.