Your pedalboard hums — which fix actually works

If the hum appears when you add a digital pedal to a daisy chain, or changes when you unplug one pedal's power, you have a ground loop. The only real fix is galvanic isolation, and that means a supply with a separate transformer winding per output rather than one rail split many ways.

Strymon publishes one custom transformer per channel across nine outputs, every one rated 500 mA at 9 V, with two switchable to 12 V or 18 V. That is enough current per output that you never have to think about which pedal goes where, which removes a second class of problem.

The cons: it is the most expensive item on this page by some margin, it has no courtesy outlets or sag feature that some rivals offer, and 500 mA per output still will not run an HX Stomp, which asks for 3 A. If that unit is on your board it needs its own supply regardless — powering an HX Stomp covers that.

A gate does not remove noise. It mutes your signal when you are not playing, which is a genuine fix for high-gain hiss between phrases and no fix at all for a hum you can hear underneath a held note. Knowing which of those you have is the whole point of the diagnostic above.

The send/return loop is the feature worth buying this for and the one most owners never wire up. Put your dirt pedals inside the loop and the gate listens to your clean guitar signal to decide when you are playing, while muting the output of the noisy chain. Used as a simple in/out pedal instead, it has to make that decision from an already-distorted signal, which is why it then chops your sustain.

The cons: BOSS is explicit that it suppresses rather than removes, so a constant hum survives it. The simple configuration audibly cuts sustain. And it is one more box plus two more patch cables in a chain you are already trying to quieten.

Before you buy a power supply, swap the patch cables. A failing solder joint or a cracked plug produces crackle, intermittent buzz and noise that changes when you nudge a pedal, and it is far more common than a genuine ground loop because patch cables are the most-flexed, cheapest part of the board.

Molded plugs have no solder joint to fail, and the flat right-angle profile sits close to the pedal so you save depth between rows. On a tightly packed board that is a practical gain as well as an electrical one.

The cons: fixed lengths mean you buy a set and live with the spacing it gives you, and there is no field repair — a molded plug that fails is a dead cable rather than something you resolder at a gig. Solderless kits solve the length problem and introduce a new failure mode; best patch cables is blunt about that trade.

The complaint about cheap gates is that they cut the end of every sustained note. ISP's approach tracks the envelope of the note rather than comparing it to a fixed level, so the gate follows the decay down instead of slamming shut at a threshold.

One Threshold knob is the entire interface, which on a dark stage is a feature rather than a limitation.

The cons: the base model has no send/return loop, so the detector listens to the already-distorted signal — the two-unit G String version is the one to buy if you want it watching your clean guitar. ISP publishes no current-draw or impedance data at all, so you cannot budget a supply output for it without measuring.

We are not recommending this as a hum fix, and it is a genuinely good product that we recommend elsewhere for small analog boards.

Truetone publishes exactly what it is: 9 V DC, 1,700 mA, from a single non-isolated output intended for daisy-chaining. That is a lot of current and it is fine when every pedal on the chain is analog and low-draw. Add one digital delay or reverb and every pedal on the chain now shares a ground with a digital circuit, which is the textbook way to manufacture the hum this page is about.

If your board is all-analog and quiet, keep it. If you added a digital pedal and the hum arrived at the same moment, the supply is the cause and no gate will fix it. Isolated vs daisy chain covers exactly where that line sits.