Shure M66 Schematic
222
HARTREY
AYE
MICROPHONES
AREA
CODE
AND
312/328.9000
EVANSTON.
ILL.
(60204)
ELECTRONIC
COMPONENTS
CABLE
SHUREMlcRo
U
S
A.
DATA
SHEET
BROADCAST STEREO EQUALIZER
MODEL M66
Broadcast
Stereo Equalizer
I
GENERAL:
the recorded frequency to a choice of three
istics-the standard RIAA, the flat, and a roll-off.
The M66 Equalizer, also, matches the impedance of the cart-
ridge to the low impedance of the line transformer giving the ad-
vantage of no high frequency losses and minimum insertion loss.
The M66 Broadcast Stereo Equalizer compensates
playback character-
SPECIFICATIONS:
Circuit:
g;ound and a 4 terminal two channel output. See Figure A for
circuit diagram.
Frequency Response Characteristic:
sign is based on the Shure M3D and M7D Stereo
having an average inductance of 365 millihenries and a DC resistance of 330 ohms. A three position switch selects different compensations. The M66 Equalizer matches and complements the frequency response within
each of the following three switch position response characteristics.
(See Fig. B)
Flat-For flat playback of recordings made without
quency pre-emphasis.
RIAA-Standard
Roll-Off-For standard recordings to reduce abnormal surface
noise.
The
impedance stereo cartridges (around 500 millihenries) and will
compensate the frequency response as shown in Figures B and
within % Idb from 30 c.p.s. to 20,000 c.p.s. but with the overall
output level down 3db. The M66 Equalizer can, also, be used with
low impedance monaural cartridges (around 175 millihenries) and
will compensate the frequency response as shown within
from 50 c.p.s. to 20,000 c.p.s. but with an increase in the overall
output level of
A
3 terminal two channel input with a common shield
The equalizer de-
Dynetic Cartridges
2
Idb from 30 c.p.s. to 20,000 c.p.s. in
high fre-
RIAA curve.
M66 Broadcast Stereo Equalizer can also be used with high
I
2db
I
db.
Output Impedance:
C
output impedances available. The unit is supplied wired for a 250
ohm output.
by a simple one wire change on a convenient terminal board located
inside the shield can.
150 ohm and 500 ohm output impedances are available
Channel Separation:
from 30
c.p.s. to 20.000 c.p.s.
The M66 Stereo Equalizer has three
Better than 30db over the entire range
Copyright
27A153 (3-67)
1960.
Shure Brothers,
Inc.
FIG.
I5O
Capacitance
CHANNEL
in
Microfarads
"A"
Resistance in Ohms
l
Watt
A
K=
55%
1000
Printed
Output Level:
M7D Stereo
12-5-71A. (Output measured with 250 ohm output impedance.)
Insertion LOSS:
"output level." The insertion loss may vary with different output
load impedances.
Hum Shielding:
designed steel case for maximum shielding.
Physical Size:
5%" deep. The panel plate is
INSTALLATION:
is designed to be mounted on a control panel with the switch
shafts coming through the
(supplied), for permanent installation where the switch shafts need
not be accessible.
The following steps are recommended for mounting to a con-
trol panel.
Using the panel plate of the Equalizer as a template, locate
I.
and mark the
switch shaft clearance holes.
2. Drill 3/16 diameter holes to clear the mounting screws and
25/64 diameter holes to clear switch shafts.
3. Mount equalizer case and panel plate to the panel using the
#8-32 machine screws. In this case, use the angle bracket
as a spacer between the equalizer case and the panel. This
allows clearance for the switch mounting nuts.
4.
Cut switch shafts to proper length and install switch knobs.
Approximately -67dbm using Shure M3D or
Dynetic Cartridge from the RCA Test Record No.
28db measured with conditions as outlined in
The M66 Equalizer is enclosed in an especially
The Equalizer case is
5"
wide and
The Model M66 Broadcast Stereo Equalizer
an el
2
mounting screw clearance holes and the 2
3%"
wide, 3" high, and
35/16"
high.
or to be mounted on a bracket,
CONNECTIONS:
use with a balanced line output or with an unbalanced line output.
For a balanced line output connection, the "high" side of the
line should be connected to the terminal marked
side of the line should be connected to the
(not coded). The shield or ground should
terminal marked GND.
For an unbalanced
the line should be connectdd to the OUT terminal marked
the ground side of the line should be connected to both the adjacent OUT terminal and the GND terminal.
used, this may, also, be connected to the GND terminal.
The two channel input (terminals marked IN) has a common
ground, as indicated on the terminal board.
In the "MONO" switch position, the two channel inputs are
shorted together for monaural operation.
GUARANTEE:
teed to be free from electrical and mechanical defects for a period
of one year from date of shipment from the factory, provided all
instructions are complied with fully. In case of damage,
sential that you carefully repack the unit and return
tory for repair. Our guarantee is voided
been
subiected to unreasonably rough handling.
The Model M66 Equalizer is designed for
+
and the "low"
adiacent "out" terminal
be connected to the
line,output connection, the "high" side of
+
and
If
a separate shield is
This Shure Broadcast Stereo Equalizer is guar-
it
is es-
it
to the fac-
if
the basic assembly has
e
24
:
LO
W
LT
W
2
%
Y
+10
.PO
+lo
0
20
M
90
FREQUENCY IN CYCLES
COMPENSATED FREQUENCYRESPONSE
FIG.
8,000
PER
SECOND
B
5POO
IOPOO
a0W
FREQUENCY IN CYCLES PER SECOND
FREQUENCY RESPONSE
FIG.
C
Loading...