Shure m63 schematic

222 HARTREY AVE., EVANSTON, IL. 60204 U.S.A. • AREA CODE 312/328-9000 • CABLE: SHUREMlCRO

General: The Shure Model M63 Audio Master is a

unit designed to give maximum flexibility in the con­trol of volume, bass response, treble response, and high
and low frequency roll-off. 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.

The Model M63-2E Audio Master is similar to Model
M63 except that it is designed to be connected to a
220-260 volt AC power line.

All information on the data sheet for the Model
M63 applies, except for those references to AC
operating voltage and power line cord.

The Audio Master features:

l 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

l Inputs for two driving sources
l A VU meter to monitor audio level
l Continuously variable high pass and low pass

6 db per octave filters

l

Bass and treble tone controls

Controls, Connections and Operation
INPUTS

The two high impedance inputs (phono jacks) marked

HIGH LEVEL INPUTS are designed to accept high

level signals from a microphone mixer such as the
Shure M68, M68RM, etc.), tape recorder, AM-FM
tuner, or output from Shure Model A68P Phonograph
Preamplifier (accessory).

To use with the Shure M68 Microphone Mixer
series, connect the AUX. HIGH LEVEL OUTPUT on
the mixer to the input of the M63 with a shielded
cable having a male phono plug on each end (such as
the Shure A68SC). 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 ¼” 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 M63, install a 180-ohm

resistor from tip to sleeve in the phone plug and use
the M63 volume control to adjust output to desired level.

Copyright 1973, Shure Brothers Inc.
27A909 (MH)

OUTPUTS

Microphone

The receptacle marked MICROPHONE LEVEL
OUTPUT 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 male audio connector de­signed to mate with Cannon XL series, Switchcraft
A3 (Q.G.) series or equivalent connector (Shure
Part 95A548). See Figure A for output receptacle
connections.

Line

The line output (binding posts) is on the rear panel
and is designated 600 OHM BALANCED LINE
OUTPUT. 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 I. While
the line output may be used to drive lines of various
impedances (150 ohms or greater), the VU meter
is calibrated for use with a 600 ohm terminated
line.

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 desig­nated 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
output will appear in both phones.

Printed in U.S.A.

MICROPHONE OUTPUT PLUG CONNECTION.

FIGURE A

SPECIFICATIONS

Specifications at 120 volts AC (M63) or 240 volts

Frequency Response: ±2 db from 20 to 20,000 Hz

Voltage Gain: (outputs terminated as noted, others

Line Output: 38.5 db (600 ohm load)
Aux. Output: 39.0 db (47 K ohm load)
Hi-Imp. Mic. Output: -1.0 db (33 K ohm load)
Lo-Imp. Mic. Output: -21.0 db (150 ohm load)

Tone Controls: Bass: +14, -19 db at 100 Hz Typ.

Filters: Hi-Cut and Lo-Cut 6 db per octave, con-

Noise Output (Line with 600 ohm load):

Volume Control min.:

74 db below +8 dbm, 20 Hz - 20 K Hz

81 db below +8 dbm, 300 Hz - 20 K Hz

Volume Control max., 4.7 K ohm source:

68 db below +8 dbm, 20 Hz - 20 K Hz
71 db below +8 dbm, 300 Hz - 20 K Hz

Distortion: Under 1% T.H.D. at +8 dbm output
Clipping Level: +18 dbm (600 ohm load)
VU Meter: Calibrated for 600 ohm line termination.

0 VU = +8 dbm ± 1 db fixed; or
0 VU = +4 dbm; output may be attenuated

Inputs:

Two, mixing. Impedance 50 K ohms 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 imped-

AC (M63-2E), 60 Hz Line Voltage.

(all controls flat)

open; volume and level control max.)

Treble: + 16,

tinuously variable -3 db point.

by 20 db.

-19 db at 10 K Hz Typ.

ance. Will operate with up to 100 ma. DC
through transformer for driving telephone lines.

Auxiliary Hi-Imp.: Unbalanced, 4.7 K ohms internal

impedance. For driving high-level, high imped­ance inputs.

Microphone Hi-Imp.:

ternal impedance. For driving medium-level high

impedance microphone inputs.

Microphone Lo-Imp.:

impedance. For driving low-level 25 to 250 ohm

microphone inputs.

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

headphones. Crystal headphones may be used.

Unbalanced, I K ohm in-

Balanced, 0.5 ohm internal

Operating Voltage:

MODEL M63:
AC Operation: 108-132 volts, at 50 to 60 HZ.
DC Operation: 30 volts, 20 ma. maximum drain
for +8 dbm output.

MODEL M63-2E:
AC Operation: 220-260 volts, at 50 to 60 HZ.

DC Operation: 30 volts, 20 ma. maximum at
+8 dbm output.

The Model M63-2E is supplied with a three­conductor power-line cord, but no plug. The
power-line cord plug should be installed by a
qualified person. The brown lead should be con-

nected to the “live” or “hot” terminal of the
plug, and the blue lead to the neutral terminal
of the plug. The green/yellow lead is the ground­ing conductor and should be connected to the
ground or earth terminal of the plug.

UL and CSA:

The M63 is listed by Underwriters’ Laboratories,

Inc. and is listed by Canadian Standards Associ­ation as certified.

Overall Dimensions: See Figure “B.”
Weight: 3 Ibs. 2 ozs. (1.4 kg)
Operating Temperature:

-7°C (20°F) to 57°C (135°F)

Guarantee: This Shure product is guaranteed in

normal use to be free from electrical and mechanical
defects for a period of one year from the date of
purchase. Please retain proof of purchase date. This
guarantee includes all parts and labor.

Shipping Instructions: Carefully repack the unit

and return it prepaid to the factory. If outside
the United States, return the unit to your dealer or
Authorized Shure Service Center for repair. The unit
will be returned to you prepaid.

OVERALL DIMENSIONS

FIGURE B

2