Shure 901D User Guide

SHURE

Micro-honnc and Acou-tic Devices

225

WEST HURON STREET

PHONE

DElaware

BROTHERS

INCORPORATED

7-4550

::

CHICAGO 10, ILLINOIS

::

CABLE: SHUREMICRO

I

DATE:

SUBJECT:

I

MAY

1949

Model

'lTurnover1'

graph

901D

Pickup

Verfical

Crvs+al

P

h

Drive

o

n o

-

MODEL

Ver+iea!

General:

designed to reproduce standard records and the various types
of fine-groove
over

mecl?ar~ism an2 the new Shure two-sided "Vertical Drive"

crystal cartridge. The crystal element is

Salt unit.

This dual-purpose cartridge utilizes the "Vertical Drive" con­struction which results in a needle-point compliance in the order
of 1.0 x

highly compliant cartridge and the Shure die-cast aluminum
pickup arm, an extremely low needle force for proper record

tracking has resulted. The dual purpose cartridge has a Shure

Model
for playing standard records at 78
A65MG sapphire tipped needle (.001" tip radius) for playing
Columbia, R.C.A. and similar fine-groove records at
or 45 r.p.m. These needles are separately replaceable. The Pick­up performs equally well on the

Model
high output and extremely low tracking force. The design of
the pickup provides record reproduction with low surface noise,
low needle talk, end low needle hiss.

LOW record wear is assured
maintains the horizontal projection of the needle

I

gent to the groove et all times), by high needle point compli­ance, and low needle pressure of 6 grsx:

An adiustment screw is provided for the swivel to protect cable is suitable for this purpose.
the

needie against damdge'due to accidental touching 'of the

'

turntable when recoid is removed.

Model
shielded lead. An arm
motor-board.

Applica3ierns:

perimenter and for

table equipment, and record demonstrators. This pickup is

especially suited for

.

well as pickups used in modern installations.

Because of low needle

I

may be used with open-type phonograph players with a mini­mum of arrnaying side tone.

The output voltdge of the pickup (see ~~ecificafions) is suf-

ficient to produce full output from audio stages of modern

radio receivers and from moderate gain amplifiers.

Bns+rril!a4ioas:

board so that the oifset needle furnished with the pickup has
an arc of travel approximately

turntdble spindle. (See Fig.

heavy and well isolated from vibrations of the motor and the

loudspeaker.

After the
dure rnay be followed to install and adjust the needle protec-

tion screw.

a. Lift the tone arm. Assemble one hex nut on the

needle protective screw and insert screw into the hole
provided in the swivel assembly bracket with the head of
the screw toward the inside oi the arm. Assemble other
hex nut to the portion of the screw
bracket. The screw and two hex nuts are provided jn the
accessory box.

b.

With a screwdriver adiust the screw until the needle knob at the front of the pickup so that the letters STD are at
point, upon lowering the tone-arm, Is maintained
mately

Copyright 1949, Shure Brothers, Inc.

Model 901D "Turnover" Phonograph Pickup is

long playing records. Model 901D uses a turn-

10-6 centimeters per dyne. By combination of this

A52A osmium tipped needle (.003" needle tip radius)

901D will give an excellent frequency response with

901D "Turnover" Pickup is provided with a 14" before making connections, so that the pickup may rotate freely

resf is included for mounting on the obout its vertical axis.

-

Model 901D is ideally suited for the ex-

use in high quality home ~hono~raphs, por-

replscunent of older, heavy ~ickups as

talk and needle hiss, the model 901D

The Pickup should be mounted on the motor-

pickup is securely mount~d the following proce-

1

/32"

above the turntable surface.

Drive

r.p.m. and a Shure Model

lo",

7".

by +he curved tone-arm (which

y4"

beyond the center of the

C).

The motorboard should be

'Turnover"

a

bimorph, Rochelle

33-55 r.p.m.

or 12" size records.

closely tan- with the playing of a 12" record.

(?$

ounce).

l/z"

extendins thro~lgh the

approxi-

2-7wr-

long

981D

Crystail

the motor-board in such a manner that

siderebly without excessive output loss.

Leads (or cable) should be allowed to extend several inchtr

the ambient temperature about the pickup at the lowest pos­sible value.
not be allowed to exceed
will result to the Pickup below

Conaeefisns:

method of connecting the leads to the cartridge.
the crystal unit is connected to ground through the shield.
this instance, the pickup may be connected
amplifier of the type using a single grid input circuit. The cen­ter conductor should be connected to the grid or "hot" lead:
the shield should be connected to the ground or chassis.
ure A shows the circuit. The chassis should be securely grounded
to eliminete shock hazard to the user.

-.

Q)per~*ig311:

the top. To play microgroove and R.C.A. slow speed records,
turn knob in the direction of the arrow until the letters

Phonograph

i

.

-

- -

c. Tighten the locking nuts securely.
The arm rest

If

necessary, the length of the leads can be increased con-

Nothing should interfere with the free motion of the Pickup.

Suificient cabinet ventilation should be provided to keep

3

MII Radius Needle

I

Mil

Pig.

should be mounted in any convenient place on

For best results the ambienf temperature should

~odel 901D pickup utilizes the pin-jack

A6iA

PPNO

On

~cd

us

Needle

(Red)

A. For Amplifiers Using a Single Grid lnpuf.

To play standard (78 r.p.m.) records, set the

Pickgap

..

-

100' Fahrenheit, although no damage

56467

~oid Tern~nol

-

-

it

Low-capacity shielded

125' Fahrenheit.

Pdn

PNo

56467

Pin

On

JOC~

Sdver Termmot.

does not interfere

directly into an

Printed

A

One side of

Arnptil,er

Chossls

MG

in

Fig-

are

U.S.A.

In

-

at the top. The knob may be used as a convenienf handle to
set the pickup on the record.

The needles may be

(which holds
serted in
curelv ~tsina the thumb and fore-finner. Care should be taken

,t

to deform the contour of the needle when the knurled nut

tightened.

Model 901D uses the Shure "Muted Stylus" needles which
may be procured in any record
at any Shure distributor. The
(.003" tip radius) precious metal tip needle which is of natural
stainless steel color and the
tip needle which is dyed red. Instead of
phire tip
graphs, when pickup is not in use nsedles can be
against accidental damage by rotating the turnover mechanism
90".

Record

impedance (resistance to side-to-side motion of the needle)
are achieved through an unique system of
ing the crystal unit. These features permit the
through the record-groove with a minimum of thrust and wear
on the side
off-set
tion of the needle closely tangential to the record grooves
throuqhout the
trackinn error, dnd' in- maximum fidelitv of reoroduction at all
frequencies. The pickup should be carefully located as specified
under "Installation"

thc needle)

the hole provided and the knurled nut tightened se-

need!* may be used for longer life. In portable phono-

Wear:

wal!s. Record wear is still further reduced by the

{earl of the pickup, which keeps the normal axis of rota-

plavinq time of the record. This results in low

rzmoved by loosening the knurled nut

l/z

turn. A new needle should be in-

shop throughout the country or

pickup is supplied with the A62A

AhSMG (.001" tip radius) sapphire

LOW needle pressure and low needle point

to derive full benefit from this feature.

A62A, an A61A sap-

protected

mounfing and coupl-

ncedle to ride

Fr'g.

C.

Physiec! Dimensions of

Vo!.kalle Sensi)i\ri*y:

the individual recording. etc. Model 90iD has an outpuf of
approximately .94 volt

No. 281 and

output on commercial records may reach 10 volts.

1.1

volts on Audiotone test record. Peak voltage

!mfertid Ipnpedance:

The output voltage depends upon

at

1000 cycles on Columbia test record

Equivalent to 650 mmf condenser.

Mode!

901D.

i'+~q~enf~ Response:

the model
cord No. 281 and Audiotone test record No.

figure
quality reproduction of records without ihe use of compensating
circuit:. Ton­and
response to suit the individual listener. FINISH GRAY HAMMER ENAMEL

I

n

v

$+I0

z

0

a

W

2

5

IlJ

a

,

The
depends upon the termination resistance. The user can thus
adjust the low-frequency response over wide limits
choice of resistance of the input potentiometer or grid resistor.

A

value of I to 2 niegohms will be satisfactory in most cases.
The
termindtion resistance. Shure patents allowed and pending.

901D obtained on Columbia micro-groove test re-

B.

This type of response

radio receivers may be employed to alter this frequency

I,

-10

50 100

Fig.

low-frequertcy response below approximately 500 cycles

high frequency response is not affected by the value of the

con:ro!s provided in the maiority of amplifiers

AFSPOHSE

-Audlorone

------CclurnSa

R.

FREQUENCY-CYCLES PER SECOND

Test

I

I

VoIxs

Output

Test

94

Volts

0ufi)ut At 1000 C l?S

Typical

Response

The frequency response curves of

I

is

very satisfactory for high

FREQUEhLY

Record

A1

1000

Rccrd

CHARACTERISTIC

COO0

No 1, 0027

Needle

C

PS

No281.001

Needle

Gharacterisfics

Tap

1

lp

Rod~u,

Rodtur.

are shown in

l0,OOO

of

904D.

p:oper

by

-

-

Recommended Load impedcifice:

depending upon the response curve desired.

I

I

CODE WORD RtJZEL

LEAD LENGTH 14"

ARM

NET WEIGHT

-

-

Guaranfee:

from electrical and mechanical defects for one year from date
of shipment from the factory, provided all instructions are com­plied with fully.

License

licensed under patents of the Brush Development Company.

NEEDLES

SHIPPING WEIGHT I2

Nofice:

MODEL

--

REST

-

Every Shure Pickup

Shure Crystal Record Reproducers are

901D

--

REPLACEABLE,

INCLUDED

4

LIFE, INCLUDED

is

guaranteed to be free

I/,

n-egohm or more.

-1

02.

LONG-

02.

I

j

27~42

(5-49)