Shure RM930C User Manual

222

HARTREY

AVE

AREA

CODE

EVANSTON,

312/328-9000

ILL.

(60204)

CABLE

SHUREMICRO

MODEL RM930C

CUSTOM MAGNETIC

CARTRIDGE

with

SPHERICAL STYLUS

(Stylus Model N75C)

SPECIFICATIONS

RM930C CARTRIDGE AND N75C STYLUS

FREQUENCY RESPONSE:

OUTPUT VOLTAGE:

5

cm/sec.

STYLUS:

TRACKABI LITY:

RM930C at 3 gram stylus force

Model N75C
Spherical Radius: ,0006 (.016 mm)
Grip Color: Blue

(Higher stylus forces within specified range improveTrackability.)

0

40

5

,,

"

20

t

85

I

lo

'I

p

e

+

4

,

TRACKING FORCE:
CHANNEL SEPARATION:
RECOMMENDED LOAD IMPEDANCE:
I

N DUCTANCE
D.C. RESISTANCE:
MOUNT1 NG:

WEIGHT:

TERM I NALS:
OPERATION:

been developed for use with all high
ma~not.ic and constant velocitv in~uts. Recommended needle force
is-~~--~o-5~~~&~&s for optimuTm results. Forces greater than 5
grams should not be used.

720 millihenries

:

Standard
new "Easy-Mount" snap-in bracket.

5

grams

4

terminals

The RM930C Dynetic phonograph cartridges have

From 20 to 20,000

9.0 millivolts per channel at 1,000 Hz.

Hz.

400

1,000

10,000

I . 6dI

TRACKABILITY CHART

3

-

Hz.

-

Hz.

-

IRIOC+*C,

to 5 grams optimum.

More than 20 db at 1,000 Hz.

630 ohms

1/2"

(12.7 nun) mounting center using

CONNECTlONS

4-LEAD STEREO CONNECTION:

channel to terminal

nel to terminal

"L"

minal
To prevent "ground loops" and hum, no common connection
should be used at cartridge terminals.

MONAURAL CONNECTION

Monaural
and "L" terminals and connect ground or shield lead to both
ground terminals marked "RG" and "LG".

MOUNTING:

centers. Hardware is provided for mounting purposes. (The brass
screws have British threads.)

1. Remove stylus guard and stylus from cartridge. (See para-

2. Remove cartridge from "Easy-Mount" snap-in bracket. (See

3.

4.

5. Connect leads to

6.

7.

8.

and shield or ground lead of left channel to LG."

01. Stereo recordings, connect "hot" lead to both

graph on stylus replacement.)
Figure

Start

mounting screws into tone arm head or plug-in shell.

Slip "Easy-Mount" bracket under heads of mounting screws

and tighten screws securely.
connection to terminal

dicated in tone-arm instruction manual.

Insert cartridge into "Easy-Mount" snap-in bracket. (See

Figure

The top of the "Easy-Mount" bracket should be flush against
the top of

unless other
record

Reinsert stylus.

"R"

"RG."

and shield or ground lead of right chan-

Connect "hot" lead of left channel

:

For single channel reproduction of

The cartridge bracket has standard

1)

phono-cartridge. ,Note color code for proper

"L,

1)

thc tone arm head for proper playing position,

mounting instructions are supplied by the

changer/tonc, arm manufacturer.

DATA SHEET

Hz.

17 cm/sec.
25 cm/sec.

11

cm/sec.

s

,

G.80

ID

X*.

Connect "hot" lead of right

"R,

YI

47,000 ohms per channel

Adelity amplifiers having

$5"

mounting

"LG"

and "RG" as in-

49

ter-

"R"

U.S.A.

at

SHIELD OF CARTRIOQE MUST BE PLACED
UNDER TAB OF BRACKET BEFORE

IN FRONT HOLE OF BRACKET.

LOCKING

OARTRIDBE BUMP IN
HOLE OF

BRACUET.

7

CARTRIDGE AND BRACKET ASSEMBLY

CAUTION:

connections to cartridge
nals. Make all solder connections
to terminal jacks provided before
slipping

Do not make solder

them over the terminals.

TERMINAL DIAGRAM STYLUS REPLACEMENT

FIGURE

2

FOR REMOVAL OF BRACKET.

I

FIGURE

ternii-

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. The alcohol will remove any

deposlts wh~ch rnay have coated the stylus tlp. The brush

sludge
brlstles should be trirrnned to a length no longer than inch.

Always

the stylus from front to back or slde to s~de.

brush the stylus with a forward movement from the rear

(terminal end of the cartridge) to the front.

Never

brush or wipe

EASY STYLUS REPLACEMENT

Grasp molded housing of stylus between thumb and forefinger.

Gently withdraw stylus by pulling forward out of cartridge. Grasp

replacement stylus between thumb and forefinger and insert
stylns socket. Press stylus into socket until the molded houslng
of the stylus mates with the cartridge case. Care must be taken
riot to allow the finger to
stylus, resulting

SPECIAL NOTE:

tridges is the rnost critical component.
performance standards of
placement
packagc: "This

by Shure

Avoid inferior imitations. They will seriously degrade the per­forriiance of your cartridge. All genuine "Dynetic" styli are
manufactured by

LABORATORY TEST FINDINGS:

test findings of the Shure N3D stylus are an example of the close
scrutiny Shure pays to all irnitation Shure
laboratory tests show that the
as replacements for the Shure
dr.astically in important performance characteristics. For 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
grarns with a high compliance stylus. The high comp1,iance stylus
retracted at 4 grams needle force, allowing the
drag on
sponse at high frequency (relative to the

5.5 db peak to a drop of 7.5 db. Separation varied from "good"

(27 db) to "poor" (16.5
is very
irnitation

from good to poor. As a matter of fact,

ruet the Shure performance standards for the Shure N3D Stereo
Dvnetic
r)&nartm~nf records show that an increasing number of Dvnetic

the record surface, thereby becoming inoperative. Re-

little

In each of the categories shown above, the results ranged

Stvlus.. In addition to our test findings, our Service

in

The Dynctic stylus assembly used in these car-

styius you buy bears the fol!owing certlficatlon on the

Stereo

Brotbers Iric."

Shu~,e Brothers Inc.

consistency in

Dynetic Styli.

shp off the molded houslng of the

darnage to the stylus tip or shank.

you^'

cartridge, be certain that any re-

To maintain the original

Dynetic stylus is precision manufactured

(Note: The following stylus

irnltation stylus assemblies labeled

blodel N3D Stylus Assembly vary

Dynetic Styli.) Shure

cartridge

lkc level) ranged from a

db)

at 1 kc. These figures reveal that there

performance

charactenstics of the

10% of the samples

only

Into

case to

2

cartridges are using irnitation

CONCLUSION:

we cannot guarantee that the pertormance of Shure
cartridges will meet the published Shure specifications. Accept no
substitute.

The Stereo Dynetic Cartridges and Stereo Dynetic Styli are
guaranteed to be free from
one year from the date of shipment
all instructions are complied with fully. The Guarantee does not
cover stylus wear, nor does it cover damage to the stylus assem­bly froni abuse or

PATENT NOTICE:

or niore of
and 3,463,889.

Copyright 1970. Shure

Obviously, if

mishandling.

the

Cartridge

follon.ing U. S. Patents 3,055,988, 3,077,521, 3,077,522

Brothe1,s Inc

Dynetic Styli.

any

imitation Dynetic Stylus is used,

Guarantee

electrical

and mechanical defects for

from the factory, provided

and stylus manufactured under one

Printed in U.S.A.

Dynetlc

27A689 (5-70)