Shure m 60 owners manual

Page 1

SHUHE

222 HARTREV AYE EVAHSTOH. |LL - CABLE SHUREMICRO

MICROPHONES AND ELECTRONIC COMPONENTS

EVANSTON PHONE DA-fl-Slil'lfl CHICAGO PHONE SH 3-160

MODEL M60

DATA SHEET

Stereo Preamplifier

STEREO PREAMPLIFIER

GENERAL: The Shure M60 Stereo Preamplifier is a high
quality, llat amplilier de gned primarily to allow the phono cart-
ridge to be used at a distance lrom the control preamplilier.

The M60 preamplilier matches the impedance ol the phono
cartridge and has dual input and dual low impedance outputs so
that up to 50 (15.2 m) leet ol cable (30MMF0 per toot) can be
used between the M60 preamplilier and the main control center
with no noticeable devia on in the entire audio lreouency response.
The M60 has l1db gain (per channel) to overcome any losses in
signal transmission. The additional gain by use ol the preamplilier,
also. reduces the hum and noise very olten present in certain high
fidelity systems.

The M60 preamplilier has a chrome plated chassis that lits under
most turntables and record changers. it is shock mounted to reduce
microphonics and acoustic feedback. The preamplilier has its own
power supply and is equipped with an ON-OFF switch.

The M6!) Stereo Preamplilier can be used as a general purpose
llat amptilier having a gain oi 17db per channel (stereo) or aadb
gain (monaural) with microphones, headsets, test equipment. etc.

Output voltages ol approximately 2 volts RMS are obtainable
betore a 10% harmonic distortion ol wavetorm is noted.

SPECIFICATIONS:

Gain: l7db per channel-s mitlivolts input produces 35 milli-
volts output.

Frequency Response: tldb lrom 30 to 00,000 c.p.s.
Equalizalian: None.

lnpul lmpedances: 47,000 ohms.

Oulpul lmpedances: 5,000 ohms.

Hum and Noise Level: aadh below rated output.
Disloriion: Less than 0.14%. 1000 c.p.s. at rated output.
Separalion Belween Channels: 30db.

Channel Balance: i 1 db.

Tubes: One dual lunction E0583112AX7.

Reclifier: Selenium-Full wave rectilication lor minimum ripple

Power Requiremenls: 111 volts 50 c.p.s. 4 watts.
Finish: chrome plate.
Overall Dimensions: Length 6-9/15 (165.7 mm); Width 2%

(57.2 mm); Height 3-3/0 (05.1 mm).

Copyright 1950. Show Brothers Inc.
27A159 (7760)

INSTALLATION: The M60 Stereo Preamplilier may be
mounted under most turntables or record changers. Rubber insola<
tion mounts are provided to reduce microphonics and acoustic
leedbaek. Figure A shows how the rubber shock mounts are in-
stalled. Machine or sell-tapping screws can be used through the 4
corner mounting holes in the preamplilier base.

WASHER SCREW
RUBBER SHOCK

CHASSIS % MOUNT

(

J b
EYELET
HEX NUT "" MOUNTING
(IF Rt-:OUlRl-:D)-\L BOARD

F I G . A

For minimum hum pickup and best operating conditions, the
preamplilier should be placed as lar away lrom the turntable motor
as conveniently possible.

Printed in U

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CONNECTIONS:
in Figure B.

To place the M60 preamplifier in operation as a two channel
stereo preamplifier, connect the signal leads from the cartridge into
the channel A and B (phone jacks marked "IN"). The output at the
preamplifier (phono jacks marked OUT") should be connected to
the main control preamplifier of the stereo system. Attention must
be given to all of the information contained in the cartridge or
phono arm data sheets regarding phasing, grounding, etc. If it is
tound necessary to ground" the M60 preamplifier chassis, a wire
can be connected to one of the screws holding the bottom plate
on to the chassis.

The internal wiring connections are shown

5RA

T. l30V m

ll7VAC

60 CPS S,

4,5 9

Capacitance in Microfarads
Resistance in Ohms

Resistors - 1/2 Watt, 110%
except R5 3. Rs, :5%

-.--..--,- _..- _----
4 I,

>

>

I
t
K;
I
I
-
Q.
I
I
I

R41:
R43

.---.§{.---.
l
03
FIG. C

FIG. 5

90V

our
CHANNEL
"All
IN
- / IN
geocaa/
l2AX7 CHANNEL
"8
90V
03 25

Voltages shown should be measured to
chassis ground using VTVM.

It the tull 17db gain is not required, lower output voltages and
lower impedances are possible with the use at a simple resistor net-
work at the output of the preamplifier. This circuit change is shown
in Figure C tor a 1/3 or a 2/3 reduction in amplitier output.

CAUTION: The electrical plug should be removed from the
power outlet before the chassis is opened or
any changes are made.

For 1/3 Reduction (2/3 output)
Replace each 5600 ohm Resistor (R3 and R.) with two Resist-
ors (R33 and Rab, R.a and R.b) having the following values:
Raa and R.a-3900 ohms, V2 watt, 110%.
Rab and R.b-1800 ohms, V2 watt, 210%.

For 2/3 Reduction (1/3 output)
Replace each 5600 ohm Resistor (R3 and R,) with two Resist-
ors (Raa and Rab, R.a and mm having the following values:
Raa and R.a-1800 ohms, V2 watt, 110%.
Rab and R4b-3900 ohms, V2 watt, 210%.

GUARANTEE: This Shure High Fidelity Component is guar-
anteed to be tree from electrical and mechanical detects tor a
period of 90 days trom date at shipment trom the tactory, provided
all instructions are complied with tully. In case ot damage, it is
essential that you caretully repack the unit and return it to the
factory tor repair. Our guarantee is voided if the basic assembly
has been opened or subjected to unreasonably rough handling.