EHX Hum debugger

[John A.]

I've been playing a P90-equipped guitar a lot lately, and really digging the tone, but the buzzing has been close to unbearable in some rooms. So after some googling for remedies, I decided to give the Electro-Harmonix Hum Debugger a whirl. It's a noise reducer that works on the same principle as noise-cancelling headphones, as opposed to a noise gate (a form of compressor)

So far, so (amazingly) good. I've only tried it at home (where the buzz is not hugely loud), but it completely zaps the hum (on its lower setting), with no noticeable effects on tone. Some reviews say there are audible artifacts (especially with high gain tones), but I didn't hear anything at all. I'll try to get to a more real world test in the next couple of days and report on that.

Buzz has also been limiting my strat use somewhat, so this looks to be a solution for that as well. Assuming it works well outside the home, this looks to be a very useful bit of gear. The only negative is it’s (non standard voltage) wall wart powered.

John

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[Max405]

John,
l’ve heard good things about this device. Vinny likes it so that’s good enough for me. But it’s nice to hear another positive review of the hum debugger.
The noise reducer in my Zoom G3 kinda doesn’t work so good. You can actually hear the bits of tone that get clipped out of the signal.
One day I will try a hum debugger!
Joe D

[neatomic]

that's because most pedal and interface amp devices use a noise gate...which works on volume threshold..so you are going to hear a breathing type noise effect in the spaces between your notes

the other way to do it is to cut the frequency...since most electric hum peaks at 60hz..they apply methodology to cancel that particular frequency...

much like a humbucker does vs a single coil!

since the low e string on guitar is 82.4hz...the hum can be removed/filtered/notched without affecting the actual fundamental

cheers

[Max405]

Neatomic, you continue to absolutely blow me away with the stuff you know.
JD

[neatomic]

thank you Joe D...the admiration is completely mutual!


cheers

[John A.]

that's because most pedal and interface amp devices use a noise gate...which works on volume threshold..so you are going to hear a breathing type noise effect in the spaces between your notes

the other way to do it is to cut the frequency...since most electric hum peaks at 60hz..they apply methodology to cancel that particular frequency...

much like a humbucker does vs a single coil!

since the low e string on guitar is 82.4hz...the hum can be removed/filtered/notched without affecting the actual fundamental

cheers

It's a little more complicated than that -- there are are harmonics that are multiples of 60Hz (especially with dimmers and transformers), and that's what you typically hear buzzing, not a 60Hz hum. The Hum De-bugger does some sort of DSP to figure out the base buzzing frequency (power is not always consistently exactly 60 Hz) and harmonics that are in play, and filters all of those, and some further DSP to keep the filter tuned on the right frequencies. There's bound to be some effect on the tone, because the signal itself at time contains frequencies that are in the power-line's harmonic series (more of the time with a distorted tone), but the effect is transient and (so far as I can tell with my set-up) undetectable.

Humbucker pups work on a different principle altogether. The coils (which have the unfortunate side effect of acting as antenna for electro-magnetic interference) are wound in the opposite direction from each other. The results in the EMI in each coil being 180 degrees out of phase and canceling the other out. The signal induced by the string is preserved, however, because the magnets are reverse polarity, which keeps the two sides of the pup in phase (out-of-phase coils + out-of-phase magnets = net in-phase signals).

John

[John A.]

John,
l’ve heard good things about this device. Vinny likes it so that’s good enough for me. But it’s nice to hear another positive review of the hum debugger.
The noise reducer in my Zoom G3 kinda doesn’t work so good. You can actually hear the bits of tone that get clipped out of the signal.
One day I will try a hum debugger!
Joe D

Noise gates that are based on compressors can be very tricky to dial in. There's always a trade-off between zapping the and noise preserving the tone. This seems to work much better. You're welcome to come and try mine if you find yourself in Manhattan.

John

[omphalopsychos]

I would get one of these if it weren't so large.

[neatomic]

well it's as complicated as you want to make it!! haha

i specifically avoided addressing how the eh product does it..but you basically have two ways...noise gate and frequency cancellation (by whatever architecture or "methodology" as i stated ^)

& of course all frequencies/notes have overtones that extend far beyond the fundamental or specific frequency...so any phase cancellation affects far more than just the specific frequency

why i like single coils!!..hah

cheers

[Doctor Jeff]

Yeah I have a HDB and have found it very useful for P90's. I have not found it much of a problem playing out interestingly, despite the variety of wiring in venues.

The standard setting has a minimal effect on tone, but the high setting does suck up a bit of tone.

[Cunamara]

Pat Metheny got one to use with his Slaman (CC pickup) and spoke of it as "solving" the noise problem completely and without affecting the tone. Hard to get a better endorsement than that!

I've been meaning to get one for use with my CC pickups, since there are some annoying buzzes in my house.

[rabbit]

Verrrry interesting & thank you'll.

I always prefer a single-coil so this might be useful knowledge.

[John A.]

well it's as complicated as you want to make it!! haha

i specifically avoided addressing how the eh product does it..but you basically have two ways...noise gate and frequency cancellation (by whatever architecture or "methodology" as i stated ^)

& of course all frequencies/notes have overtones that extend far beyond the fundamental or specific frequency...so any phase cancellation affects far more than just the specific frequency

why i like single coils!!..hah

cheers

In broad strokes, yes, it's cutting frequencies selectively rather than acting as a noise gate, and humbuckers do also cut frequencies (but without any sort of explicit logic other than phase cancellation).

Just to clarify what I meant about how (I think) the HDB works ... from what I've read, the HDB is not filtering a single pre-determined frequency. Rather, it's reading the frequency of the line voltage in real time (which varies) and constantly tuning its filter. I don't know enough about AC, dimmers etc. to digest your point about how zapping the fundamental would take care of the harmonics. My sense is that it wouldn't because the fundamental (say, 60hz) might not be part of the noise that's read by the coil, and the HDB is filtering the guitar's output, not the source of the noise. The HDB's DSP has to "know" what the fundamental is from the line voltage in order to identify that harmonics to filter out, but filtering just the fundamental might not be sufficient to zap the harmonics the coil is detecting. But I might be thinking this through wrong.

John

[Stringswinger]

I had and used one of these pedals. I found that it worked very well with a solid state amp, but with a tube amp, there were some strange overtones on a few notes. Eventually I decided that living with the buzz (a very infrequent problem) was better than carrying the extra gear, so away it went.

[MikeTT]

I'm using a humfree P90 from Fralin and it works great. It's a rather low output P90 and I mostly play clean with it, but it made P90 work for me.

[John A.]

I'm using a humfree P90 from Fralin and it works great. It's a rather low output P90 and I mostly play clean with it, but it made P90 work for me.

I thought about replacing the pup, but this solves the buzz problem for my strat as well without a visit to the luthier, which works for me.

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[Boston Joe]

Some of the reviews say it adds a sort of a metallic, boxy type of overtone to the sound. Yes? No?

[John A.]

Some of the reviews say it adds a sort of a metallic, boxy type of overtone to the sound. Yes? No?

Through my amp at home, using the "normal" setting at various volumes no. From what I understand, the tone effect kicks in on the strong setting, and is exaggerated by overdriven sounds (OD won't be an issue with my hollowbody). I'm hoping to try it tonight in the place that has given me the most trouble, where no amount of pointing my guitar in other directions helps and the buzz is really loud. I'll find out whether I need the "strong" setting, and if so whether that has any audible effects.

John

[Doctor Jeff]

Some of the reviews say it adds a sort of a metallic, boxy type of overtone to the sound. Yes? No?

I don't think so. The normal setting is barely noticeable. The high setting seems to suck out some of the brightness, actually not too bad for a dark Jim Hall tone.

BTW the biggest hum problem I had was with a Godin P90 through an acoustic SS amp. Not such a problem with my Tele.

[feet]

for general hum and buzz duties, i use a combination of my empress buffer + and a tc electronic sentry. the sentry is a noise gate with a few settings (and all that tone print business) for your standard noise and the buffer+ handles some of the more high end hiss and weirdness and such in my rig with my billion pedals and the noisy power in my place.

the sentry doesn't really affect tone (unless you make it) but it can trim notes and tails depending on where it's set. the buffer+ has the most minute high end reduction as you set it higher, but you can barely notice it even if you're looking for it. means nothing in context.

i remember hearing the hum debugger added weirdness and i don't trust ehx so i stayed away. glad it is working out for all.

[John A.]

I don't think so. The normal setting is barely noticeable. The high setting seems to suck out some of the brightness, actually not too bad for a dark Jim Hall tone.

BTW the biggest hum problem I had was with a Godin P90 through an acoustic SS amp. Not such a problem with my Tele.

Ditto with the Godin P90. The biggest problem is at my local weekly Jam. The room is full of dimmers, a ceiling fan, and miscellaneous HVAC stuff. Pointing yourself 90 degrees from a noise source doesn't help because the sources are everywhere. I used the hum debugger last night, and it worked. I tried both settings and thought "strong" might have had some artifacts, but wasn't sure. Normal killed the hum without artifacts. Next up: Strat, which was pretty bad in this room.

John

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[Donelson]

I am replying to this old thread, because reading the posts here convinced me to order one of these EHX Hum Debuggers.

A friend recommended this product to me a few years back, but I saw a lot of negative comments online & assumed that it was a crappy gimmick. So I never tried one.

I recently have gotten curious about it again, as I got a guitar that I call "jazz tele" that has a C. Christian-styled neck PU, fairly heavy strings, wound 3rd. Yes, it has the regular SC hum. I have a few other axes with SC PUs as well.

I am only interested in a jazz/clean/solo application for this for now. No mega fuzz or pedalboard stuff. Just a regular SC guitar sound with the hum gone.

Once I get the Hum Debugger, I will make a new thread. Hopefully a positive review. Or maybe, "it's a dud" etc. Hope not that. We'll see.

[pcjazz]

I have been using the hum debugger with my single-coil-equipped guitars. It does the job.

[campusfive]

I bought a hum debugger since I'm playing a 1937 ES-150.

There have only been two or three venues where I really felt I needed it (of course, one of them is at my biggest and most important gigs every year, lol). And those venues the noise is so bad, it's almost something out of "Spinal Tap".

At the high setting (which was required in all of these places), I definitely heard some weird artifacts, but it almost sounds like a subtle flanger. I'm playing though somewhat gritty 30's-style octal tube amps, so there's some gain involved.

Still, I have to pack it for emergencies.

[morroben]

I got one a while back. I don't use it all the time but it works well when I need it. I don't find much tone-change on the low setting. The high setting affects the tone a bit more, but not in a particularly negative way. I can fiddle with some knobs and get back to what I was hearing before.
The only real downside is that it requires it's own special power supply.