Shure Models 315 and 315S Gradient
bi-directional ribbon microphones

Hear the sound of this mic.

General
The Models 315 and 315S are compact and rugged ribbon microphones combining wide range response and a bidirectional pickup pattern. The bidirectional pattern reduces noise and reverberation providing the same control as an equivalent cardioid microphone. The Models 315 and 315S are ideal for high-quality public address, theater stage sound systems, and recording applications. Due to the bidirectional polar pattern, they may be used for either single performer, a dialogue or group, solo or orchestra, and other individual or chorus applications.

The Models 315 Gold and 315S Gold feature a gold-colored finish.
Specifications in other respects are the same as for the standard models.

Microphone Features

• Wide-range front and rear response
  
  
• Bidirectional polar pattern, effective over wide frequency range
  
  
• Convenient impedance selection
  
  
• A strong detachable cable especially selected for good shielding from “hum” pickup
  
  
• A self-adjusting swivel permits aiming microphone at source of sound
  
  
• Rugged mechanical design with special ribbon protection

The Models 315 and 315S are multi-impedance for connecting into microphone inputs rated at 25 to 50 ohms, 150 to 250 ohms, or into high impedance microphone inputs. The low impedances are recommended where long cable lengths are required or under conditions of severe hum disturbance. The permissible cable length is practically unlimited, since neither response nor level is appreciably affected. For use with high impedance amplifiers, the Shure Model A95UF Line Matching Transformer is available for coupling the low impedance line to the amplifier input.

Impedance Selection
Selection of the various impedances is accomplished by removing a plate and changing the position of the switch at the rear of the microphone. The switch positions are marked “L” for low impedance (25-50 ohms), “M” for medium impedance (150-250 ohms), and “H” for high impedance (35,000 ohms).

• Frequency response: 50 to 12,000 Hz (see Figure B)
  
  
• Polar Pattern: Bidirectional, equally sensitive at front and back. Response at sides down 15 to 20 dB from front and rear responses (see Figure C)
  
  
• Switch: Model 315 none, Model 315S built-in “ON-OFF” switch to control microphone circuit. The switch is an integral part of the receptacle assembly and is a slide-to-talk locking type switch
  
  
• Case: Chrome-plated die cast
  
  
• Net Weight: 1 pound (454 grams)
  
  
• Introduced: 1952
  
  
• Discontinued: 1977

Photographs courtesy of Dennis Schrank

The following three photos are also courtesy of Dennis Schrank,
and portray the Shure 315S microphone. Note the switch.

Download the Data Sheet for these mics.