1. Introduction
The Alctron HA-18 is a compact and lightweight active volume amplifier designed for personal in-ear monitoring applications. It features an amplify circuit to boost audio signals, a BAL/STEREO mode switch for versatile input handling, and a volume control knob that also serves as the power switch. Its durable plastic construction and battery-powered operation make it highly portable for musicians, performers, and audio professionals.
2. Features
- Personal monitor with integrated volume control.
- Designed specifically for in-ear monitoring applications.
- Power status indicator LED.
- BAL (Balanced) mode for balanced signal sources.
- STEREO mode for unbalanced sources such as headphone outputs or stereo devices.
- Lightweight and durable plastic construction.
- Powered by two AAA batteries for portability.
3. Setup
- Battery Installation:
- Locate the battery compartment on the HA-18 unit.
- Insert two 1.5V AAA batteries, ensuring correct polarity (+/-).
- Close the battery compartment securely.
- Input Connection:
- Connect your audio source (e.g., mixer output) to the XLR 1/4" combo input jack on the HA-18. This input supports both XLR and 1/4" TRS/TS connectors.
- Headphone Connection:
- Plug your in-ear monitors or headphones into the 1/8" (3.5mm) headphone output jack.
- Mode Selection:
- Set the BAL/STEREO switch according to your input source:
- BAL: Select this mode for balanced signal sources (typically from a mixer's balanced output via XLR or TRS).
- STEREO: Select this mode for unbalanced stereo sources, such as a headphone output from another device.
4. Operating Instructions
- Power On/Off:
- To power on the unit, rotate the volume knob clockwise from the 'OFF' position. The green power LED will illuminate.
- To power off, rotate the volume knob counterclockwise until it clicks into the 'OFF' position and the green LED extinguishes.
- Volume Adjustment:
- Adjust the output volume to your headphones by rotating the volume knob. Start with a low volume and gradually increase to a comfortable listening level.
- Monitoring:
- Ensure your audio source is active and sending a signal. Listen through your connected headphones.
- If using a balanced source, ensure the BAL/STEREO switch is set to BAL. If using an unbalanced stereo source, set it to STEREO. Incorrect setting may result in phase issues or missing audio channels.
5. Maintenance
- Cleaning: Use a soft, dry cloth to clean the exterior of the unit. Do not use liquid cleaners or solvents.
- Battery Replacement: When the power LED dims or the audio output becomes weak or distorted, replace the AAA batteries. Always replace both batteries at the same time with new ones.
- Storage: If storing the unit for an extended period, remove the batteries to prevent leakage and damage. Store in a cool, dry place.
- Handling: The HA-18 features a lightweight plastic construction. Handle with care to avoid physical damage.
6. Troubleshooting
- No Sound:
- Check if the unit is powered on (green LED illuminated).
- Ensure batteries are correctly installed and not depleted.
- Verify all audio cables are securely connected to both the HA-18 and the audio source/headphones.
- Confirm the volume knob is turned up.
- Check the BAL/STEREO switch setting matches your input source.
- Test with different headphones or audio source to isolate the problem.
- Distorted Sound:
- Reduce the input level from your audio source.
- Check battery level; low batteries can cause distortion.
- Ensure cables are not damaged.
- Only Sound in One Ear:
- Verify the BAL/STEREO switch is set correctly for your input source. A stereo source connected with the switch in BAL mode may result in mono or partial audio.
- Check headphone connection and cable for damage.
7. Specifications
| Parameter | Value |
|---|---|
| Input channel | stereo/bal |
| Analog input | 1 x XLR 1/4'' combo (line in) |
| Analog outputs | 1 x 1/8'' (headphone) |
| Frequency response | 20~20kHz |
| Input impedance | XLR~20K, TRS~10K |
| Magnification | 1.3x |
| Gain | 2dB |
| Output power | @16Ω, 30MWx2; @32Ω, 20MWx2; @100Ω, 10MWx2 |
| Distortion | ≤1% |
| Noise | ≥-70db |
| Power | 2*1.5V AAA battery |
8. User Tips
- Always start with the volume knob at its lowest setting before connecting headphones to prevent sudden loud sounds.
- For optimal performance and battery life, use high-quality alkaline or rechargeable AAA batteries.
- When using the HA-18 with a mixer, it's often best to send a balanced mono signal to the HA-18 and set the switch to BAL for a clear, focused monitor mix.
- The integrated belt clip allows for convenient attachment to clothing or instrument straps, keeping the unit accessible during performances.
9. Warranty and Support
For warranty information, technical support, or service inquiries, please contact your authorized Alctron dealer or the manufacturer directly. Keep your purchase receipt as proof of purchase for any warranty claims.
