Monoprice 138162 70V Rotary In-Wall Volume Control 25W 11 Positions

In-wall 70V volume control

The Monoprice 138162 is a rotary in-wall volume control designed for 70V distributed audio systems. It provides 11 discrete volume positions using make-before-break contacts for smooth adjustment. The unit handles a maximum load of 25 watts and mounts in a standard single gang junction box. It suits installers needing simple zone level management for background music or paging systems.

Check system voltage and load

Verify that your speaker line operates on a 70V constant-voltage topology before ordering. Confirm the total speaker tap wattage on the zone does not exceed 25 watts, as this is the control's maximum rated load. Ensure the wall cavity can accommodate a single gang box and that wiring follows local code for in-wall low-voltage installations. Two units fit side-by-side in a dual gang box if multiple zones are required.

Passive operation with no fan noise

The control contains no active electronics, so it draws no power and produces zero audible noise during use. Heat dissipation is negligible at or below the 25 watt rating, requiring no special ventilation. Insertion loss is minimal thanks to the make-before-break contact design. Long-term reliability depends on staying within the specified load and voltage limits.