Operating Instruction Manual TOA PROFESSIONAL GRAPHIC EQUALIZER Model E 131 TOA ELECTRIC CO., LTD.
Contents Precautions . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 1 General Description . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Features . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 2 Specifications . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . . 3 Appearance . . . . . . . . . . . . . . . . . . . . . . . . . . . . . .
General Description The TOA E 131 is a single channel, 1/3 octave active graphic equalizer designed to allow clean, accurate audio equalization for stage, studio, or commercial applications. The E 131 provides 12 dB of boost or cut at each of its 28 frequencies, which are centered at ISO 1/3 octave increments from 31.5 Hz to 16 kHz. Its signal to noise ratio is over 120 dB making the E 131 one of the quietest equalizers on the market.
Specifications Frequency Response ±ldB, 20Hz to 20kHz Indicators A red LED for output clipping A green LED for equalizer IN A green LED for power ON Controls Equalizer Sliders ±12dB Input Level Control ±12dB High Pass Filter 18dB per octave Adjustable Cutoff Frequency: 15Hz to 120Hz Low Pass Filter 12dB per octave Adjustable Cutoff Frequency: 8kHz to 25kHz Total Harmonic Distortion Less than 0.2% at 1kHz, all sliders at 0 position, rated output Equalization Center Frequencies 31.5Hz to 16kHz 31.
Performance Graphs Frequency Response (Each slider is set at a max or min position) Frequency Response (All sliders are set at a max position) Frequency Response (ex.
Front Panel Peak Indicator LED The peak indicator LED will glow when the output level reaches 6dB below clipping. It is quite common for the LED to flash on and off during high level operation. However, if the LED remains steadily lighted, the input level control or the output level of associated equipment should be lowered until the LED only flashes at the highest peaks. High Pass Filter Control This shelving-type filter provides an 18dB per octave rolloff between 120Hz and 15Hz.
Rear Panel Power Fuse (Fuse 0.5A, 0.3A) Fuse for 220/240V AC operation should be 0.3A and 0.5A for 120V AC. AC Inlet The power cord must be plugged into it. * Power Cord Clamp A plastic covered metal clip is provided to prevent accidental disconnection of the AC power cord. Ground Lift Switch The ground lift switch is effective to avoid ground loops that are often caused in connection with other equipment and that may induce hum.
Input / Output Connections Mixing Console (RX-7) E 131 (L) E 131 (R) Power Amplifier (P 150D) Speaker System (38-SD×2) -7-
Installation Precautions Ground Loops In any audio system, there are numerous ways by which ground loops can be created. For example, they may occur when the E 131 is mounted in a rack cabinet, or through AC ground when the E 131 is connected with preamps, mixers, etc. These ground loops may cause hum and noise if care is not taken during connection. An increase in noise from ground loops may be minimized by breaking the ground loop.
Applications Feedback Prevention When the overall gain of a sound system is increased, feedback will occur at frequencies where the system response has peaks. Suppose the system has an uneven frequency response like that shown in the following diagram. The frequency at which feedback will occur when gain is increased is about 500Hz. In this case, feedback may be prevented by attenuating levels at 500Hz by 3dB to 5dB with the E131.
Applications Equalization for music The Graphic Equalizer is designed not only for use in preventing feedback and equalizing uneven room frequency response to be flat, but also for equalizing frequency response to your tastes and producing favourable sound for you. Fig. 1 shows each frequency band and its corresponding auditory feeling. Fig. 2 and table 1 show the relation between each musical instrument and its frequency band. They can be of great help in the equalizer operation.
TOA ELECTRIC CO., LTD.
