2 2 2 HARTREY AVE
E V A N S T O N , ILL. ( 6 0 2 0 4 )
AREA CODE 312/328-9000
U.S.A.
CABLE SHUREMICRO
MODEL RM930C
CUSTOM MAGNETIC
CARTRIDGE
with
SPHERICAL STYLUS
(Stylus Model N75C)
DATA SHEET
SPECIFICATIONS
RM930C CARTRIDGE AND N75C STYLUS
From 20 to 20,000 Hz.
9.0 millivolts per channel a t 1,000 Hz. a t
F R E Q U E N C Y RESPONSE:
OUTPUT VOLTAGE:
5 cm/sec.
STYLUS:
Model N75C
Spherical Radius: ,0006 (.016 mm)
Grip Color: Blue
TRACKABI LITY:
RM930C a t 3 gram stylus force
400 H z . - 17 cm/sec.
1,000 Hz. - 25 cm/sec.
10,000 Hz. - 11 cm/sec.
(Higher stylus forces within specified range improveTrackability.)
5 ,,
0 40
"
20
t
85
I
' lI
o
p
+
e
4
,
I
.
6 d I
s
IRIOC+*C,
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,
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ID
YI
TRACKABILITY CHART
T R A C K I N G FORCE: 3 to 5 grams optimum.
C H A N N E L S E P A R A T I O N : More than 20 db a t 1,000 Hz.
47,000 ohms per channel
720 millihenries
D.C. RESISTANCE: 630 ohms
MOUNT1 NG: Standard 1/2" (12.7 nun) mounting center using
new "Easy-Mount" snap-in bracket.
W E I G H T : 5 grams
T E R M I N A L S : 4 terminals
O P E R A T I O N : The RM930C Dynetic phonograph cartridges have
been developed f o r use with all high Adelity amplifiers having
ma~not.icand constant velocitv i n ~ u t s Recommended
.
needle force
i s - ~ ~ - - ~ o - 5 ~ ~for
~ &optimuTm
~&s
results. Forces greater than 5
grams should not be used.
RECOMMENDED LOAD IMPEDANCE:
I N DUCTANCE :
CONNECTlONS
Connect "hot" lead of right
channel to terminal "R" and shield or ground lead of right channel to terminal "RG." Connect "hot" lead of left channel 49 terminal "L" and shield or ground lead of left channel to LG."
T o prevent "ground loops" and hum, no common connection
should be used a t cartridge terminals.
M O N A U R A L CONNECTION : F o r single channel reproduction of
Monaural 01. Stereo recordings, connect "hot" lead to both "R"
and "L" terminals and connect ground or shield lead to both
ground terminals marked "RG" and "LG".
M O U N T I N G : The cartridge bracket has standard $5" mounting
centers. Hardware is provided for mounting purposes. (The brass
screws have British threads.)
1. Remove stylus guard and stylus from cartridge. (See paragraph on stylus replacement.)
2. Remove cartridge from "Easy-Mount" snap-in bracket. (See
Figure 1)
3. Start mounting screws into tone arm head or plug-in shell.
4. Slip "Easy-Mount" bracket under heads of mounting screws
and tighten screws securely.
5. Connect leads to phono-cartridge. ,Note color code for proper
connection to terminal "L,
"R, "LG" and "RG" a s indicated in tone-arm instruction manual.
6. Insert cartridge into "Easy-Mount" snap-in bracket. (See
Figure 1)
7. The top of the "Easy-Mount" bracket should be flush against
the top of thc tone arm head f o r proper playing position,
unless other mounting instructions are supplied by the
record changer/tonc, arm manufacturer.
8. Reinsert stylus.
4 - L E A D STEREO CONNECTION:
SHIELD OF CARTRIOQE MUST B E PLACED
UNDER TAB OF BRACKET BEFORE LOCKING
IN FRONT HOLE OF BRACKET.
OARTRIDBE BUMP I N
HOLE OF BRACUET.
7
FOR REMOVAL OF BRACKET.
CARTRIDGE AND BRACKET ASSEMBLY
FIGURE I
Do not make solder
connections to cartridge terniinals. Make all solder connections
to terminal jacks provided before
slipping them over the terminals.
CAUTION:
TERMINAL DIAGRAM
FIGURE 2
STYLUS REPLACEMENT
FIGURE 3
Suggestions for Cleaning Your Stylus
To clean the stylus, use a camel's-hair brush {No. 2 size or
smaller) dipped lightly in alcohol. T h e alcohol will remove a n y
sludge deposlts w h ~ c hrnay have coated the stylus tlp. T h e brush
brlstles should be trirrnned to a length no longer t h a n
inch.
A l w a y s brush the stylus with a forward movement from t h e rear
(terminal end of the cartridge) to the front. Never brush o r wipe
the stylus from front to back o r slde to s ~ d e .
EASY STYLUS REPLACEMENT
Grasp molded housing of stylus between thumb a n d forefinger.
Gently withdraw stylus by pulling forward out of cartridge. Grasp
replacement stylus between thumb a n d forefinger and insert Into
stylns socket. P r e s s stylus into socket until t h e molded houslng
of the stylus mates with the cartridge case. Care must be taken
riot to allow the finger to s h p off the molded houslng of the
stylus, resulting i n darnage to the stylus tip o r shank.
S P E C I A L N O T E : T h e Dynctic stylus assembly used in these cartridges is the rnost critical component. T o maintain t h e original
performance standards of you^' cartridge, be certain t h a t a n y replacement styius you buy bears the fol!owing certlficatlon on the
packagc: "This Stereo Dynetic stylus is precision manufactured
by Shure Brotbers Iric."
Avoid inferior imitations. They will seriously degrade the perforriiance of your cartridge. All genuine "Dynetic" styli a r e
manufactured by S h u ~ , eBrothers Inc.
L A B O R A T O R Y T E S T F I N D I N G S : (Note: T h e following stylus
test findings of the Shure N3D stylus a r e a n example of the close
scrutiny Shure pays to all irnitation Shure Dynetic Styli.) Shure
laboratory tests show t h a t the irnltation stylus assemblies labeled
a s replacements for the Shure blodel N3D Stylus Assembly vary
dr.astically in important performance characteristics. F o r example,
the compliance varied froni a low of 0.9 to a higll of 11.5, requiring
9.0 grams to track a record with a low compliance stylus, and 2
grarns with a high compliance stylus. T h e high comp1,iance stylus
retracted a t 4 grams needle force, allowing the cartridge case to
d r a g on the record surface, thereby becoming inoperative. Response a t high frequency (relative to the l k c level) ranged from a
5.5 d b peak to a drop of 7.5 db. Separation varied from "good"
(27 d b ) t o "poor" (16.5 db) a t 1 kc. These figures reveal t h a t there
is very little consistency in performance charactenstics of the
irnitation Dynetic Styli.
I n each of t h e categories shown above, t h e results ranged
from good to poor. As a matter of fact, only 10% of the samples
ruet the Shure performance standards for the Shure N3D Stereo
Dvnetic Stvlus.. I n addition to our test findings, our Service
r ) & n a r t m ~ n records
f
show t h a t a n increasing number of Dvnetic
cartridges a r e using irnitation Dynetic Styli.
C O N C L U S I O N : Obviously, if any imitation Dynetic Stylus is used,
we cannot guarantee t h a t the pertormance of Shure Dynetlc
cartridges will meet the published Shure specifications. Accept no
substitute.
Guarantee
T h e Stereo Dynetic Cartridges and Stereo Dynetic Styli a r e
guaranteed to be free from electrical and mechanical defects f o r
one year from the date of shipment from the factory, provided
all instructions a r e complied with fully. The Guarantee does not
cover stylus wear, nor does it cover damage to the stylus assembly froni abuse or mishandling.
P A T E N T N O T I C E : Cartridge and stylus manufactured under one
or niore of the follon.ing U. S. Patents 3,055,988, 3,077,521, 3,077,522
and 3,463,889.
Copyright 1970. Shure Brothe1,s I n c
27A689 (5-70)
Printed in U.S.A.