Shure PS1A User Manual

The Shure Model PS1A is an AC power supply that provides
phantom power for one or two Shure SM81, SM82, SM85, or other
condenser microphones. The PS1A can be used with either
balanced or unbalanced low-Impedance microphone inputs, and is
designed to handle both microphone and line-level signals. It
features extremely low noise, hum and RF susceptibility. The PS1A
will operate over a wide range of AC voltages, and provides short-
circuit-proof-operation.
The PS1A contains a power switch, power-on indicator, two each
male and female XLR connectors, and an internal voltage selector
switch for 240-volt, 50/60 Hz operation.

FEATURES

• Phantom powers one or two Shure condenser microphones or
similar condenser microphones
• Use with balanced or unbalanced microphone inputs
• Low noise, hum and RF susceptibility
• Short-circuit-proof operation
• Operates with both microphone and line-level signals
• Usable over wide ac voltage ranges
• Three-pin XLR audio connectors
• Lightweight
• Rugged Construction

SPECIFICATIONS

Type
All-silicon-transistor power supply
Open Circuit Supply Voltage
21.5 ± 1.5 Vdc, regulated (see Figure 1)
Supply Voltage Polarity
Positive (+) on three-socket microphone connector pins 2 and 3;
negative (–) on pin 1 and case
2006, Shure Incorporated
©
27A8087 (Rev. 1)
Typical Supply Operating Conditions (each channel)
20 V at 1.5 mA (with Shure SM81 or SM85); 15 V at 8 mA (with
Shure SM82)
Power Supply Resistors
1.69 k ± 1% (two per channel; see Figure 1)
Frequency Response
+0/ –0.2 dB, 20-20,000 Hz (with SM81 or SM85 and 1k load)
Maximum Operating Level
Greater than ±24 dBm
Short Circuit Supply Current
25 mA each channel (pins 2 and 3 to pin 1)
Hum and Noise (20 Hz-20 kHz, unweighted)
Common Mode: –90 dBV maximum
Differential Mode: –115 dBV maximum
Noise (300 Hz-20 kHz, unweighted)
Common Mode: 100 dBV maximum
Differential Mode: –115 dBV maximum
A-weighted, measured with true rms voltmeter
Differential Mode: –131 dBV maximum
Crosstalk
–115 dB or less
Phasing
Corresponding pins of all connectors are in phase
Operating Voltage
90-132 VAC, 50/60 Hz or 180-264 VAC, 50/60 Hz (internal
switch-selectable); power consumption 3 watts maximum
Temperature Range
Operating: –7° to 57° C (20° to 135° F)
Storage: –29° to 71° C (–20° to 160° F)
Connectors
Professional audio (XLR): male (Output) and female (Micro-
phone)
Dimensions
72 mm H x 156 mm W x 150 mm D (2-27/32 in. x 6-5/32 in.
x 5-29/32 in.)
Weight
1.25 kilograms (2 lb 12 oz)
Construction
Aluminum front panel with steel cover; finished in gray enamel
Certifications
Listed by Underwriters Laboratories, Inc.; listed by Canadian
Standards Association as Certified
Model PS1A User Guide
Printed in U.S.A.