18V AC-AC Power Adapter, 1000mA (1A) Wall Transformer, 2.1mm x 5.5mm Plug | AC-181A

18V AC-AC Linear Wall Transformer — 1000mA (1A) |

Part AC-181A

The AC-181A is a linear wall-mount AC-to-AC power adapter delivering 18V AC output at 1000mA (1 Amp). This is a specialty adapter for devices that specifically require 18VAC alternating current (~) — most commonly professional audio equipment, security alarm transformers, and HVAC/smart home controllers. If your device's label shows 18V~ or 18VAC, this is the adapter you need.

⚠️ Critical Note: This is an AC-AC adapter. It outputs alternating current (~), NOT DC (⏳). Using an AC-AC adapter on a DC-only device can cause permanent damage. Verify your device requires AC output before purchasing.

Technical Specifications

• Model: AC-181A
• Input: 120V AC, 60Hz (standard US wall outlet)
• Output: 18V AC @ 1000mA (1 Amp)
• Connector: 2.1mm (ID) x 5.5mm (OD) straight barrel plug
• Type: Linear wall-mount transformer (non-regulated)

Common Use Cases & Compatible Devices

• Audio Equipment: Professional pre-amps, mixers, guitar multi-effects pedals (certain legacy Digitech, Line 6, Rocktron rack units)
• Security Systems: 18VAC alarm control panels, door chimes, and CCTV camera heaters
• HVAC & Smart Home: Specialized thermostats, zone controllers, and irrigation system controllers requiring 18VAC
• Networking: Certain older modems and industrial routers that use AC voltage

Common Replacement Compatibility

Frequently used as a direct replacement for 18VAC 20VA/40VA alarm transformers and OEM adapters for Alesis, Digitech, and Rocktron audio gear. Always verify your device's rated current draw does not exceed 1000mA (1A).

Frequently Asked Questions

Q: How do I know if my device needs AC or DC?
A: Check the power input label on your device. AC is indicated by the ~ symbol or the letters VAC. DC is indicated by ⏳ or VDC. If it says DC, this adapter will not work.

Q: Why does my voltmeter read higher than 18V?
A: Linear transformers are non-regulated. The output voltage reads higher under no-load (nothing plugged in) and settles to the rated 18V when a load is applied. This is normal behavior.

Q: Is this compatible with international voltages?
A: No — this unit is designed for 120V AC 60Hz (US/Canada only).

Q: What if I need a different voltage?
A: See our full AC-AC adapter line for 6V, 9V, 12V, 14V, and other voltages.