NGD: Electro-Harmonix Hum Debugger – Review

Electro Harmonix Hum Debugger - amazing voodoo magic for eliminating hum.

I decided to scrap my original post and provide a properly written review.

Since I picked up my Blackstar HT-5, and got rid of my Zoom G7.1ut I’ve been having to deal with noise issues related to electrical interference in my house.

My parents were on a trip overseas, finishing up in Hong Kong, so I thought I would do some research on noise reduction devices, and see if my parents could pick me up a pedal to take care of the noise without breaking the budget.

My suggestions were the MXR Smart Gate and the Electro Harmonix Hum Debugger.

My parent’s came back with the Hum Debugger, and the experiment began as to where I should place it in my rig for the best results.

For starters lets look at the controls for the EHX Hum Debugger. It really couldn’t get any simpler with this unit, there is a 2 way toggle switch labelled “Normal” and “Strong”, and the foot switch to engage the unit. A green LED lets you know that the device is on, and it runs on a 7.5 Volt AC adapter, so no batteries or daisy-chaining to your regular 9 Volt adapter.

It’s a little bit annoying that the pedal is powered by a non-standard power supply, but once you fire up the unit and see it in action you get over this.

The Hum Debugger is not a noise gate as such, so it doesn’t cut everything out that’s making a sound, and kill sustain at higher levels. It is designed to cut out 60 cycle hum and the like from your signal. That’s the hum you get from standard single coil pickups, and the sort of noise you can get from other electrical devices in your circuit.

Essentially it looks for the harmonic frequencies occupied typically from this sort of hum and noise and kills them. The normal setting knocks out the odd harmonics in the hum, and the strong setting takes out both odd and even.

I found that there are two ways you could use the Hum Debugger, the way recommended in the manual, and the way I discovered. Both work in different ways.

The manual recommends that you place your Hum Debugger in front of your amp, and first in the chain from your guitar. This works great if you are the sort of player who loves vintage type single coils (like in a Strat or Tele) and predominately played with a clean or slightly dirty amp tone. The pedal does a brilliant job of killing off that nasty single coil hum.

This is all well and good, but if you are like me and prefer to crank up the gain a bit more issues with your tone start to emerge.

With the gain cranked right up at 3 o clock on my Blackstar HT-5 the Hum Debugger introduced a nasty electronic-like reverb sound to my tone. I liken it to the effect used for the Darleks in Doctor Who. Very cool for crazy sounds and mucking around, but extremely undesirable when you want your nice pure high gain tone. The strong setting made the effect even more pronounced.

I was starting to think that I made the wrong choice of pedals, and was starting to regret getting my parent’s to hunt this down.

In last ditch attempt to find a positive outcome I hooked up the Hum Debugger in the effects loop, and discovered a far better result. On the normal setting at high gain the hum was for the most part wiped from my sound, and my tone seemed to not be affected at all. The Hum Debugger might have lowered the amp’s volume just a fraction, but my tone was there, and sounded much stronger and clearer in the moments of silence as I played riffs.

There was still the slightest hint of the hum on the normal setting, so I tried switching over to the strong mode, and wiped the last little bit of hum out. This setting did slightly colour my tone, but not in an absolutely horrible way like the pedal did in front of the amp.

I believe that because the Hum Debugger was sitting outside of the pre-amp section, the gain created from here was not getting filtered through the pedal. I think that the gain created by a cranked pre-amp section probably covers the same sort of harmonic territory as 60 cycle hum, and this is why the strange reverb type effect occurs with the pedal in front of the amp.

I decided that the normal setting was fine as what was left of the hum was barely noticeable anyway.

The only down side with using the Hum Debugger in the effects loop is that it does not take care of the hum from your single coils so much. But in reality most players that utilise a predominately high gain tone don’t really use single coils too often. It certainly isn’t really an issue for me. If I’m playing around with single coil tones I’m either using my EMG equipped guitar, or using positions 2 and 4 on my H-S-H axes.

So at the end of the day I think the Electro Harmonix Hum Debugger is a fantastic pedal when used in two different ways: In front of the amp for those players preferring vintage type single coil sounds with clean or low gain tones, and in the effects loop for those players preferring high gain tones predominately using humbuckers.

Either way I suggest you head down to your local Electro Harmonix dealer and try the pedal out yourself, I think you will be pleased with the results with either style.

I have also reviewed this on Jemsite’s comparison shopping. Go check it out for more reviews on this product, and prices at different online stores.