The 10 Best Hum Eliminators & Ground Loop Killers (2026)
Gear Guides · Meshplugins.com
That 60-cycle buzz in your monitors isn't a broken cable — it's electricity taking two paths to ground and turning the difference into sound. The fix costs from $21, once you know which box to buy.
The diagnosis
IT'S A GROUND LOOP
Two paths to ground = hum. Break the loop, keep the safety
Ten picks, ranked and priced, with the honest logic behind each one.
Related: every piece of studio gear, ranked - The Bibles, the 10 best pedalboard patch cables and the 10 best power conditioners.
The 10 best hum eliminators
1. Morley Hum Exterminator — the ground-loop classic
The plug-between box that kills ground-loop hum at the AC connection without lifting safety ground — the fix for the buzz that appears the moment you connect amp and interface to different outlets.
Check the price at Sweetwater → · $81.97
2. ART DTI 2-channel — the isolation workhorse
A passive dual transformer isolator: put it in any stereo line connection and ground-loop hum disappears, because the transformers break the electrical path the hum rides on. Every studio should own one before it owns a second compressor.
Check the price at Sweetwater → · $72.89
3. Behringer MicroHD HD400 — the $21 problem solver
The famous little box that has rescued a thousand live streams: two channels of transformer isolation for twenty dollars. Keep one in every gig bag — the day the PA hums, you're the hero.
Check the price at Sweetwater → · $20.90
4. Electro-Harmonix Hum Debugger — the pedalboard hum surgeon
EHX's pedal strips mains hum from a guitar signal in real time — the tool for single-coil players under fluorescent lights. It targets the hum itself, not the loop, which makes it the companion to isolators rather than a substitute.
Check the price at Sweetwater → · $161.50
5. Morley MHE 2-channel Stereo — the stereo rig protector
Morley's dual-channel isolator for stereo pedal rigs and keyboard setups — both channels isolated, hum gone, tone left alone.
Check the price at Sweetwater → · $108.99
6. ART T8 8-channel — the rack-scale cure
Eight channels of transformer isolation in one rack unit: the fix for whole-studio ground-loop nightmares — multi-output interfaces feeding monitors, headphone amps and video rigs at once.
Check the price at Sweetwater → · $184.99
7. iFi GND Defender — the audiophile take
iFi's compact defender detects and breaks ground loops on the mains side with hi-fi-grade parts — a favorite in listening rooms and mastering-adjacent setups.
Check the price at Sweetwater → · $99.00
8. Morley Humno — the compact standalone
Morley's little Humno tackles noisy single lines in a box small enough to velcro anywhere — tidy solution for one stubborn connection.
Check the price at Sweetwater → · $109.00
9. iFi iDefender+ CC — the USB-loop killer
Half of modern studio hum arrives over USB. The iDefender+ breaks the USB ground path between computer and interface — the fix nobody thinks of because the cable looks digital and innocent.
Check the price at Sweetwater → · $59.00
10. ISP Hum Extractor + Decimator G — the high-gain system
ISP's rack system pairs hum extraction with their famous Decimator noise reduction — built for high-gain guitar rigs where hum, hiss and noise all need killing at once.
Check the price at Sweetwater → · $466.00
Quick compare
| Box | Where it works | Channels | Price |
|---|---|---|---|
| Morley Hum Exterminator | AC/mains side | 1 | $81.97 |
| ART DTI | Line/signal side | 2 | $72.89 |
| Behringer HD400 | Line/signal side | 2 | $20.90 |
| EHX Hum Debugger | Guitar signal | 1 | $161.50 |
| Morley MHE Stereo | Line/signal side | 2 | $108.99 |
| ART T8 | Line, rack scale | 8 | $184.99 |
| iFi GND Defender | AC/mains side | 1 | $99.00 |
| Morley Humno | Line/signal side | 1 | $109.00 |
| iFi iDefender+ CC | USB ground | 1 | $59.00 |
| ISP Hum Extractor rack | Guitar system | 2 | $466.00 |
How to find your hum in five minutes
Unplug things until it stops. Start with everything humming, then disconnect one cable at a time — the cable that silences the room is the loop path. If it's an audio line, a transformer isolator (DTI, HD400) goes there. If it only stops when a whole device leaves the wall, treat the mains side (Hum Exterminator, GND Defender). If pulling USB kills it — the iDefender is your fix.
The rule that keeps you alive: never solve hum with a ground-lift adapter that removes the safety pin. That pin is what stands between a fault and your hands on a live chassis. Every box on this list breaks the loop while keeping the safety ground intact — that's the entire reason they exist.
The honest part
Half of home-studio hum cases are solved free: plug everything into one outlet strip so ground potential is identical everywhere. Do that first. Buy the box when the free fix isn't enough — and keep an HD400 in the bag anyway, because someone else's rig will hum at the worst moment.
FAQ
What causes ground loop hum?
Two pieces of connected gear grounded through different outlets create a loop; tiny voltage differences between the grounds drive current around it, and your audio lines pick it up as 50/60Hz hum.
How do I get rid of ground loop hum cheaply?
First plug all connected gear into one power strip. If hum remains, a $21 transformer isolator like the Behringer HD400 in the offending line usually kills it completely.
Is it safe to use a ground lift adapter?
No - removing the safety ground pin turns a hum problem into an electrocution risk. Use transformer isolation or a proper AC-side eliminator that preserves the safety ground.
Why does my guitar hum but stop when I touch the strings?
That's typically single-coil pickup hum plus your body acting as a shield, not a ground loop. Shielding the guitar cavity or a hum-stripping pedal like the Hum Debugger addresses it.
Sources
Sweetwater hum eliminator search · Sound on Sound — ground loops explained · Radial — grounding and isolation notes
Love the data? Steal the sound.
The Vocal Chain Bible breaks down 88 real vocal chains from 70+ artists — exact plugins, signal order, and free alternatives. 5+ years and 100+ Grammy interviews in one PDF.
Get the Vocal Chain Bible →More real talk → Meshplugins.com · every piece of studio gear, ranked - The Bibles
— IvanFromRnD
Prices and availability are accurate at the time of writing and can change — the links go to the live product page. Affiliate disclosure: Meshplugins.com is a participant in the Sweetwater affiliate program. If you buy through the links on this page we may earn a commission at no extra cost to you. This never changes which gear we recommend — every pick here is chosen on merit.
Who's behind this
Ivan Meshcheriakov · IvanFromRnD
5+ years ago I moved to LA with zero connections and started building from nothing — 14-hour days, meeting people and interning at studios. It took me 5+ years to meet and interview 100+ Grammy-winning engineers — then I turned it all into the Vocal Chain Bible.
Read my full story →