Power Supply Isolation Explained

The Voltage Rule (The Kill Switch)

This is the most important rule in pedal power. Voltage must match the pedal's rating exactly (or be slightly lower if the pedal allows it). Never exceed the stated voltage.

This isn't a suggestion. If you plug an 18V cable into a 9V digital pedal, it doesn't just sound bad—it permanently dies in a cloud of smoke. The magic smoke escapes, and there's no getting it back.

Water Analogy: Voltage is the pressure in the pipe. Current (mA) is the water reservoir. If the pressure is too high, the pipe bursts. If you have a huge reservoir but the pedal only needs a small amount, that's perfectly fine.

The Current (mA) Reality

Current is where most beginners worry for no reason.

Important: A pedal only draws what it needs. If a pedal draws 10mA, and you have a 500mA output available, that's perfectly safe (and actually runs cooler, since the supply isn't maxed out).

Pro Tip: Digital pedals like delays, reverbs, and modulation effects demand high current (often 100-300mA each). Analog pedals are lightweight (10-50mA). If you're planning a digital-heavy board, you need a supply that can handle it. The Cioks DC7 is the pro choice because it delivers high, stable current across multiple isolated outputs.

Isolation: The Game-Changer

Daisy chaining (connecting pedals in a series with one power cable) creates a shared ground. This is where the hum comes from.

Isolation means each output has its own isolated circuit. No shared ground = no ground loop hum.

The Digital vs. Analog Problem (The "Noisy Neighbors")

This is where isolation becomes non-negotiable.

Digital pedals (delays, reverbs, modulation effects) generate clock noise—a high-frequency digital artifact that bleeds into every shared ground.

If you daisy chain a digital delay with an analog overdrive, the delay's clock noise will bleed directly into your dirt pedal. You'll hear a digital comb-filter artifact behind your tone—sometimes subtle, sometimes obvious depending on the pedals.

Isolation is the only fence that keeps those neighbors apart.

The Rule: If you have even ONE digital pedal (like a Boss DD-8 delay or Strymon Timeline), you need isolation. Period. Daisy chaining will cause noise.

Brand Distinctions (This Matters)

Truetone 1-Spot: Two Different Products

There's massive confusion here, and it causes real problems.

1-Spot Combo Pack ("Daisy Chain"): A $30 wall-wart with 6-outlet daisy chain string. This is the "starter." It works fine for 3-4 pure analog pedals. Add a digital delay? Prepare for hum.

1-Spot Pro (CS6/CS7/CS12): A fully isolated power supply that competes directly with Voodoo Lab. The CS12 has 12 isolated outputs. This is NOT a daisy chain—it's a professional-grade isolated brick.

Don't confuse these two. The naming is confusing on purpose (marketing).

Cioks DC7: The Pro Secret

The Cioks DC7 is NOT "budget." At $230+, it's arguably the most expensive and powerful compact supply on the market. It's the Ferrari of power supplies.

Why pros love it: Slim form factor that fits under any board, incredibly stable current delivery, and enough mA to power digital-heavy rigs without noise or sag.

Voodoo Lab Pedal Power 3+: The Industry Standard

For 25+ years, Voodoo Lab has been the go-to. It's not flashy, but it's bulletproof. If you want zero noise and don't care about cost, buy this.

Budget Alternatives (For Real)

If you want true isolation at a lower price point than Cioks DC7:

• Harley Benton ISO-1 Pro: ~$60-80. Entry-level isolation. Works for small boards.
• Vitoos AD10: ~$100. Compact, fully isolated, decent current capacity.

Neither matches Cioks DC7 in power or stability, but both beat daisy chaining hands down.

Polarity: The Silent Killer

Most guitar pedals are center-negative (center pin is negative, outer ring is positive). Some exceptions exist (pedals designed in other regions, some vintage gear).

Wrong polarity = instant death. The magic smoke escapes. Don't guess—always check the pedal's specs before plugging in.

The Pro Setup

1. Measure the total mA draw of your board (add up every pedal's current draw)
2. Choose a supply that provides at least 20% headroom above your total
3. Plug high-current digital pedals (delays, reverbs) into isolated outputs
4. Keep isolated outputs available for each pedal if possible
5. If you must share outputs, pair only analog pedals together

Do this right, and your board will be dead silent. Do it wrong, and you'll be troubleshooting hum for years.