Introduction
The Jieotwice EQ-888 is a 2U dual 31-band digital audio equalizer designed for professional sound reinforcement applications. It features advanced circuit design, high-quality components, and an intuitive interface for precise audio control. The EQ-888 offers a wide frequency response of 10Hz-50KHz, a signal-to-noise ratio greater than 90dB, and total harmonic distortion less than 0.005%, ensuring clear and accurate sound processing. Its built-in DSP memory allows for saving up to 10 custom equalization modes, and balanced inputs/outputs minimize noise for optimal performance.
Safety Information
Please read and understand all safety instructions before operating the EQ-888. Retain this manual for future reference.
- Electrical Safety: To prevent fire or electric shock, do not expose this equipment to rain or moisture. Do not open the casing; there are no user-serviceable parts inside. Refer all servicing to qualified service personnel.
- Power Supply: Ensure the unit is connected to a grounded power outlet with the correct voltage (AC 100-240V). Disconnect power before making any connections or adjustments.
- Ventilation: Ensure adequate airflow around the unit. Do not block ventilation openings, as this can lead to overheating.
- Placement: Place the unit on a stable surface or mount it securely in a standard 19-inch rack. Avoid placing it near heat sources or in direct sunlight.
Product Overview
Front Panel
The front panel provides access to all primary equalization and control functions, including volume, gain, frequency band adjustments, and preset management.
Figure: Front view of the EQ-888 with approximate dimensions (480mm width, 180mm depth, 100mm height).
Figure: Detailed view of the EQ-888 front panel controls.
- CONTROL Knob (Left): Used for volume adjustment and menu navigation.
- GAIN Knob (Right): Used for adjusting the level of selected frequency bands and overall gain.
- Frequency Band Display: LED indicators show the level for each of the 31 frequency bands.
- Digital Display: Shows current volume level, preset number, or mode.
- Function Buttons (Right): Includes buttons for PRESET, RECALL, BYPASS, and SAVE.
Rear Panel
The rear panel houses all audio input and output connections, along with the power input and switch.
Figure: Rear view of the EQ-888 showing input/output ports and power connection.
- Power Switch: Toggles the unit's power on or off.
- AC Power Input: Standard IEC power connector for AC 100-240V power supply.
- Input 1 (RCA): Unbalanced stereo audio input.
- Input 2 (XLR): Balanced mono audio input.
- Input 3 (TRS): Balanced mono audio input.
- Output 1 (RCA): Unbalanced stereo audio output.
- Output 2 (XLR): Balanced mono audio output.
- Output 3 (TRS): Balanced mono audio output.
Setup
- Unpacking and Inspection: Carefully remove the EQ-888 from its packaging. Inspect the unit for any physical damage that may have occurred during shipping.
- Placement: Position the equalizer on a stable, flat surface or mount it into a standard 19-inch equipment rack. Ensure there is sufficient space around the unit for proper ventilation.
- Power Connection: With the power switch in the OFF position, connect the supplied AC power cable to the AC power input on the rear panel of the EQ-888. Then, plug the other end into a suitable, grounded AC power outlet.
- Audio Connections:
- Connect your audio source (e.g., mixer, media player) to the desired input ports (RCA, XLR, or TRS) on the rear panel.
- Connect the outputs of the EQ-888 to your amplifier, powered speakers, or the next audio processing device in your signal chain using the corresponding output ports (RCA, XLR, or TRS).
- For optimal noise reduction, use balanced XLR or TRS cables for connections where possible.
- Initial Power On: Once all connections are secure, switch the power button on the rear panel to the ON position. The unit will undergo a brief two-second power-on delay before becoming fully operational.
Operating Instructions
1. Volume Adjustment
To adjust the overall output volume of the EQ-888:
- Rotate the left CONTROL knob clockwise to increase volume or counter-clockwise to decrease it.
- The digital display will show the current volume level.
- Press the CONTROL knob once to switch from volume adjustment mode to frequency band adjustment mode.
Figure: Volume Adjustment. Rotate the left knob to change the volume level.
2. Frequency Band Adjustment
To adjust specific frequency bands:
- From the volume adjustment state, press the left CONTROL knob. The blue light under the frequency band display will flash, indicating that you are in band adjustment mode.
- Turn the left CONTROL knob to scroll through and select the desired frequency band (e.g., 1KHz). The selected band's indicator will flash.
- Turn the right GAIN knob to increase or decrease the level of the selected frequency band.
- Press the GAIN knob again to confirm the adjustment and exit band adjustment mode.
Figure: Frequency Band Adjustment. Use the left knob to select a band and the right knob to adjust its level.
3. Recall/Restore Presets
To load a previously saved equalization preset:
- Press the RECALL button. The digital display on the right will flash, showing a number from 1 to 10, representing the available preset modes.
- Turn the left CONTROL knob to select the desired preset mode (1-10).
- Press RECALL again to load the selected preset. The equalizer settings will instantly change to the stored configuration.
Figure: Recalling Presets. Select and load one of the 10 stored equalization modes.
4. Channel Switching (Spectrum Mode)
The EQ-888 supports different channel display modes:
- Press the SELECT button (located near the right knob). The digital display will cycle through modes 1, 2, and 3.
- Display 1: Corresponds to the first single channel mode.
- Display 2: Corresponds to the second single channel mode.
- Display 3: Corresponds to dual-channel mixed mode, showing both channels simultaneously.
5. EQ Direct Connection (Bypass)
To bypass the equalization effect:
- Press the BYPASS button. The audio signal will pass through the unit directly without any equalization processing. This is useful for A/B comparisons or when no equalization is desired.
Figure: EQ Bypass and Save Function. The BYPASS button allows the signal to pass without equalization.
6. Save Custom Presets
To save your current equalization settings as a custom preset:
- Adjust the equalization settings to your desired configuration.
- Press the SAVE button. The digital display will flash, showing a number from 1 to 10, indicating the available preset slots.
- Turn the left CONTROL knob to select the desired preset slot (1-10) where you want to store your current settings.
- Press SAVE again to confirm and store the settings. The settings are now saved and can be recalled later.
Maintenance
- Cleaning: Use a soft, dry cloth to clean the exterior surfaces of the EQ-888. Do not use liquid cleaners, abrasive materials, or solvents, as these can damage the finish or internal components.
- Ventilation: Regularly check that the ventilation openings on the unit are clear of dust and debris to ensure proper airflow and prevent overheating.
- Storage: If the unit will not be used for an extended period, disconnect it from the power supply and store it in a cool, dry environment, away from direct sunlight and extreme temperatures.
Troubleshooting
| Problem | Possible Cause | Solution |
|---|---|---|
| No power | Power cable not securely connected; Power switch is off; Faulty power outlet; Defective power connector contact. | Ensure the power cable is firmly plugged into both the unit and the wall outlet. Turn the power switch ON. Test the power outlet with another device. If the power connector feels loose or intermittent, contact support. |
| No sound output | Incorrect audio connections; Input source not active or muted; Output device (amplifier/speakers) off or muted; EQ bypass is active. | Verify all audio cables are correctly connected to the appropriate inputs and outputs. Ensure your audio source is playing and the receiving device is powered on and not muted. Check if the BYPASS function is engaged. |
| Sound distortion or hum | Improper gain staging (input/output levels too high); Ground loop interference; Damaged audio cables; Extreme frequency band settings. | Adjust input and output gain levels to prevent clipping (indicated by red LEDs). Ensure proper grounding and use balanced cables (XLR/TRS) to minimize hum. Inspect all audio cables for damage. Reduce extreme boosts on frequency bands. |
| Equalizer settings not applying | EQ bypass is active; Incorrect operating mode selected. | Deactivate the BYPASS function by pressing the BYPASS button. Ensure you are in the correct mode for active equalization, not just volume adjustment. |
| Display shows same information for both channels (not true stereo) | Unit operating in mono or mixed display mode; Potential internal fault. | Press the SELECT button to cycle through channel display modes and ensure dual-channel mixed mode (Display 3) is selected if stereo operation is desired. If the issue persists, contact customer support. |
Specifications
- Model Number: EQ-888
- Manufacturer: Jieotwice
- Part Number: JOT-230321-10
- Packaging Dimensions: 52.6 x 28.1 x 15.2 cm
- Packaging Weight: 3.96 kg
- Frequency Response: 10Hz-50KHz
- Signal-to-Noise Ratio: >90dB
- Total Harmonic Distortion: <0.005%
- Channel Isolation: >90dB
- Power Supply: Built-in, AC 100-240V
- Memory: Built-in DSP memory for 10 preset modes
- Batteries Included: No
- ASIN: B0BZ42CP7L
- First Available Date: March 21, 2023
Warranty and Support
This Jieotwice EQ-888 Digital Audio Equalizer comes with a standard manufacturer's warranty. For specific details regarding warranty coverage, duration, and terms, please refer to the warranty card or documentation included with your purchase. It is recommended to retain your purchase receipt as proof of purchase for any warranty claims.
For technical support, troubleshooting assistance beyond this manual, or service inquiries, please visit the official Jieotwice website or contact their customer support team directly. Contact information can typically be found on the product packaging or the manufacturer's website.