Electronics / AV Switchers
User Manual for av:link 128.425UK/128.428UK Loudspeaker Selector
Quick guide for the av:link 128.425UK and 128.428UK loudspeaker selectors. Learn how to install, connect speakers, use the impedance protection circuit, and understand technical specifications.
Table of contents
Manual images
Click an image to enlargeQuick guide from the manual
The av:link loudspeaker selector allows you to distribute a stereo amplifier signal to multiple speaker zones. Key features include heavy-duty push-button activation for each zone and a built-in impedance protection circuit. The device is designed for 4-16 ohms speakers.
Installation
Before connecting, ensure your amplifier is powered off. Use 14-gauge to 18-gauge speaker wire for connections. For behind-the-wall installations, use UL Class 3 (CL3) approved cable to comply with building regulations.
- Strip the wire: Remove 3/8 inch of insulation from the ends of the cable and twist the strands to prevent fraying.
- Connect to the unit: Press the push-pin on the rear terminal to reveal the eye, insert the exposed wire, and release the pin to lock it in place.
- Maintain Polarity: Always connect the positive (+) terminal on the speaker to the positive (+) terminal on the selector, and the negative (-) terminal to the negative (-) terminal. This applies to both amplifier inputs and speaker outputs.
Operation and Impedance Protection
The unit features a Single Pair Direct switch on the front panel. This activates an impedance protection circuit.
- ON: Use this setting to prevent the impedance presented to your amplifier from dropping below an unsafe level of 5 Ohms, regardless of the number of speakers connected.
- OFF: This setting can be used if you are utilizing a planned system of impedance-matching volume controls.
Technical Specifications
The following specifications apply to the 128.425UK (4-way) and 128.428UK (8-way) models:
- Listening zones: 4 (128.425UK) or 8 (128.428UK)
- Power handling (Protection ON): 70W per channel (128.425UK) / 100W per channel (128.428UK)
- Power handling (Protection OFF): 140W per channel (128.425UK) / 200W per channel (128.428UK)
- Protection circuit: 10 Ohm/15W resistors per channel
Safety Warnings
- Do not immerse the device in water or expose it to damp conditions.
- Ensure there is sufficient space above the unit for heat dissipation from the ventilation grilles.
- Do not attempt to repair or disassemble the device, as this will invalidate the warranty.
- If the device is damaged, do not use it.
Practical help
Common problems
Impedance drops below safe levels
Turn ON the 'Single Pair Direct' impedance protection circuit to keep impedance above 5 Ohms.
Sound distortion or amplifier overheating
Ensure proper ventilation above the unit and verify that the impedance protection setting is appropriate for your speaker configuration.
No sound from a specific zone
Check that the corresponding push-button on the front panel is engaged and verify the cable connections at the rear terminals.
Before use
- Ensure amplifier is turned off before connecting
- Check speaker impedance (designed for 4-16 ohms)
- Prepare 14-18 gauge speaker wire
- Verify polarity (+/-) for all connections
- Ensure adequate ventilation space above the unit
Specs in practice
- Listening zones
- The number of independent speaker sets that can be connected and controlled.
- Power handling (Protection ON)
- Maximum power capacity when impedance protection is active, providing a safer load for the amplifier.
- Power handling (Protection OFF)
- Maximum power capacity when impedance protection is bypassed; requires impedance matching volume controls.
Images and diagrams
- Front panel: Features push buttons for zone selection and the Single Pair Direct switch.
- Rear panel: Features spring clip terminals for amplifier inputs and speaker outputs.
Model compatibility
- Designed for 4-16 ohms speakers.
- Compatible with 14-gauge to 18-gauge speaker wire.
- For behind-wall installations, use UL Class 3 (CL3) approved cable.
Manual page author
Michael Turner
Technical manual editor
Reviews PDF manuals for structure, safety notes, and practical product details so readers can find the right information quickly.