⚡🔌 9V DC Power Supply (Center‑Negative)

This adapter delivers 9V of regulated DC power using a barrel connector with center-negative polarity. It’s commonly used in guitar pedals, audio gear, and select legacy electronics that require reverse polarity. Available in multiple plug sizes to match device input jacks.
 
🔧 Charger Form
Input: 100–240V AC, 50/60Hz
Output: 9V DC @ 1A to 2A (varies by model)
Polarity: Center-negative (⊖●⊕) — outer positive, inner negative
Voltage: Regulated 9V DC
Common aliases: “9V reverse polarity adapter,” “center-negative barrel supply,” “guitar pedal power supply”
 
🔧 Plug Variants
1️⃣ 5.5mm × 2.5mm Barrel Plug
Use Case: Standard for many pedalboards, effects chains, and legacy AV gear
Example Devices: BOSS-style pedals, Digitech, Behringer, Zoom, older cassette decks
Notes: Slightly deeper socket than 5.5/2.1mm; verify fit before use
2️⃣ 3.5mm × 1.3mm Barrel Plug
Use Case: Compact gear with smaller DC jacks
Example Devices: Mini pedals, analog synth modules, IR blasters, portable audio accessories
Notes: Lower current capacity; ideal for devices under 500mA
 
🖥️ Compatible Devices
🟦 Guitar & Audio Equipment
BOSS DS‑1, TU‑3, DD‑7
Electro‑Harmonix Nano series
Digitech RP and BP series
Behringer FX pedals
Zoom G1X, A1X
Pedalboards with daisy-chain power inputs
🟦 Legacy & Embedded Electronics
Mini radios and cassette players
Barcode scanners and IR modules
DIY synth kits and analog gear
Portable speakers and AV accessories
 
✅ Common Uses
🔌 Powering guitar pedals and effects chains
🧩 Replacing lost or damaged OEM 9V center-negative adapters
🧪 Running audio gear without batteries
🧵 Essential entry for musicians, audio techs, and pedalboard builders
 
🧠 Signal Format
⚡ Input: Universal AC (100–240V)
🔋 Output: Regulated 9V DC, center-negative
🔌 Barrel connector: 5.5×2.5mm or 3.5×1.3mm
🔁 Not interchangeable with center-positive 9V adapters
 
⚠️ Things to Watch Out For
🔄 Polarity matters — center-negative is not standard for most consumer electronics
🔌 Do not use with center-positive devices — risk of damage
🧯 Always check the polarity symbol on the device or manual
📏 5.5/2.5mm may not fit snugly in 5.5/2.1mm jacks — test before use
📉 3.5/1.3mm plugs have lower current capacity — avoid overloading
 
🛠️ Quick Tips for Beginners
🧭 Look for the polarity symbol: ⊖●⊕ (center-negative)
🔌 Match both voltage and polarity exactly
🧪 Use with daisy-chain cables for multiple pedals
🧯 Label clearly to avoid mix-ups with center-positive 9V supplies
🧵 Keep both plug sizes in your toolkit for maximum compatibility