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Operating Instruction Manual
TOA PROFESSIONAL GRAPHIC EQUALIZER
Model E 131
TOA ELECTRIC C O . , LTD.
KOBE, JAPAN
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Contents Precautions ................................................ 1 General Description ........................................ 2 Features ................................................... 2 Specifications ............................................. 3 Appearance ................................................ 3 Performance Graphs ....................................... 4 Front Panel ................................................ 5 Rear Panel ..........................................
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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. The E 131's active bandpass/bandreject filters are designed f
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Specifications Frequency Response Indicators ±ldB, 20Hz to 20kHz A red LED for output clipping A green LED for equalizer IN Total Harmonic Distortion Less than 0.2% at 1kHz, all sliders at 0 position, rated A green LED for power ON output Controls Equalization Center Frequencies Equalizer Sliders 31.5Hz to 16kHz ±12dB 31.5Hz, 40Hz, 50Hz, 63Hz, 80Hz, 100Hz, 125Hz, 160Hz, Input Level Control 200Hz, 250Hz, 315Hz, 400Hz, 500Hz, 630Hz, 800Hz, 1kHz, ±12dB 1.25kHz, 1.6kHz, 2kHz, 2.5kHz, 3.15kHz, 4kHz,
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Performance Graphs Frequency Response Frequency Response (Each slider is set at a max or min position) (All sliders are set at a max position) Frequency Response (ex. 800Hz slider) High pass & Low pass Filters – 4 –
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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. It is especial
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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. Sliding the ground lift switch from a NORM position to the LIFT po
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Input / Output Connections Mixing Console (RX-7) E 131 (L) E 131 (R) Power Amplifier (P 150D) Speaker System (38-SD×2) - 7 -
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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. Generally, the chassis ground of the signal line should be bro
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Applications Feedback Prevention When the overall gain of a sound system is increased, prevented by attenuating levels at 500Hz by 3dB to 5dB with feedback will occur at frequencies where the system response the E131. If the overall gain is again gradually increased, has peaks. Suppose the system has an uneven frequency feedback will occur next at about 125Hz. It may be stopped by response like that shown in the following diagram. The attenuating the levels 2dB to 3dB at that frequency. In this
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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. (They are refe
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TOA ELECTRIC CO., LTD. KOBE, JAPAN Printed in Japan 133-02-674-8
