222 HARTREY AVE., EVANSTON, IL, 60204 U.S.A.
AREA CODE 312/866-2200 • CABLE: SHUREMlCRO
DATA SHEET
TWX: 910-231-0048
TELEX: 72-4349
MODELS M64 AND M64-2E
M I C R O P H O N E S A N D E L E C T R O N I C C O M P O N E N T S
STEREO PREAMPLIFIERS
GENERAL
The Shure Models M64 and M64-2E Stereo Pre-
amplifiers are designed to furnish the voltage gain
and equalization necessary to operate magnetic
phono cartridges (such as the Shure DYNETIC
®
Cartridges), and tape playback heads with audio
amplifiers that have no equalization. In addition, the
units may be used without equalization for micro-
phones or as buffer amplifiers.
Typical Applications:
l
Conversion of stereo record playing systems
from ceramic to magnetic cartridges.
l
Preamplifier for microphones.
l
Low gain buffer amplifier where long cable
lengths are extended to a preamplifier input.
Advantages include complete freedom from micro-
phonics, extremely low noise, the ability to use
15m (50 ft) or more of output cable, and years of
maintenance-free performance. The operating tem-
perature range is from 7°C (20°F) to 57°C (135°F).
The Model M64 operates on 108-132 volts, 50/60
Hz power line, or from an auxiliary 24 to 36 volt dc
supply such as the Shure Model A67B Battery Power
Supply. The M64-2E is identical to the M64 except
that it operates on a line voltage of 216-264 volts,
50/60 Hz.
The Model M64 and M64-2E feature a single 3-
position slide switch for selecting equalization for
Phono, Tape, or Flat. The Phono position provides
the Standard RIAA Equalization for phono records.
The Tape position provides the Standard 7½ IPS
NAB Equalization for tape, and the Flat position
provides a flat amplifier for microphones or as a
buffer amplifier for magnetic phono cartridges when
long lines or switching systems are necessary
between the turntable and main equalized pre-
amplifier. (NOTE: When used as a buffer amplifier,
the Low Level Outputs should be used). The input
and output jacks will accept standard phono plugs.
There are input jacks for Channel 1 and Channel 2;
output jacks for Ch. 1 High Level, Ch. 1 Low Level,
Ch. 2 High Level, and Ch. 2 Low Level.
Copyright 1984, Shure Brothers Inc.
27A2076 (DB)
SPECIFICATIONS
Gain
Gain measured at 1 kHz with input through 680
ohms and output terminated in 47 kilohms.
Equalization
High Level
Low
Level
Switch Position
output
output
Flat
+27.5 dB
+ 4.0 dB
Phono
+34.5 dB
+11.0 dB
Tape
+37.0 dB
+13.5 dB
Frequency Response
Flat:
± 2 dB from 20 Hz to 20 kHz
Phono:
± 2 dB of the Standard RIAA curve from
40 Hz to 15 kHz
Tape:
± 2 dB of the 7½ IPS NAB curve from
50 Hz to 15 kHz
TYPICAL FREQUENCY RESPONSE
FIGURE 1
Distortion
Under 1% total harmonic distortion for an output
of 2 volts at 1 kHz in Phono, Tape or Flat positions.
In the Phono position the total harmonic distortion
is less than 1% at 30 Hz with 2 volts output.
Clipping Level
The minimum input clipping levels at 1 kHz are:
Flat: 250 mV
Phono: 100 mV
Tape: 80 mV
Channel Separation
50 dB or better at 1 kHz
Channel Balance
Channels matched within 2 dB at 1 kHz
Printed in U.S.A.
