New Godin Kingpin and P90 noise problem

**Doctor Jeff** · 02-28-2010, 09:54 PM

I am now the proud owner of a Godin Kingpin, with a single P90 pickup. It is a beaut, well-made and smooth-sounding. In case you're wondering, I am keeping the round-wound .012 strings and Tusq bridge for now to get used to the sound before changing anything out.

The problem is pickup noise. There is a terrible ground loop hum that probably comes from my home's wiring. It's so bad that if I had known about it beforehand, I wouldn't have gotten the guitar, or maybe would have gotten the acoustic version and added a floating humbucker or such. I can mitigate it by playing with the guitar and amp facing in a certain direction.

I have done a little research and am thinking about getting an Electro-Harmonic Hum Debugger. I have also come across a couple of products by Behringer that might be a cheaper alternative. Any thoughts?

**JimBobWay** · 02-28-2010, 10:21 PM

More likely, a combination of electrical issues, including grounding or lack thereof, polarity, and maybe some other interference. I use a Furman Power Conditioner in my home studio and my gig rack. It might be overkill for your needs but they have several models, and are used by professional sound engineers worldwide. First try plugging in to a GFCI outlet (bathroom?) and see if that fixes it. Then it's a grounding issue, and will affect other appliances - at that point you might want to have an electrician look at your wiring and circuit breakers. Safety first!

**kaige** · 03-01-2010, 01:34 AM

Eliminate the variables. Play the guitar at a buddy's house to determine if it is
the guitar or the house which is causing the hum.
Avoid fluorescent lights.

**Little Jay** · 03-01-2010, 05:41 AM

it might be another simlpe defect: ground wire came loose or even wires soldered badly or incorrectly at the pots.

I can't image house-wiring to cause that much noise.. I play my single coil instruments through ungrounded outlets in my house and only very close to my computer or very close to the amp they generate noise.

Do you maybe have a dimmed lamp close to your guitar or amp? Or any other device with a trafo?

**Meggy** · 03-01-2010, 08:23 AM

Originally Posted by kaige

Eliminate the variables. Play the guitar at a buddy's house to determine if it is
the guitar or the house which is causing the hum.
Avoid fluorescent lights.

Or if you have another guitar which doesn't hum at your own house, this would also confirm the guitar as the culprit. Of course single coil pickups are susceptible to mains hum though - all you can do is make sure the rest of the wiring is well shielded with no ground loops. I have found that doing this with a single coil guitar does help a lot with removing noise, but you will still get some hum/buzz if playing near mains cables/flourescent lights/the tv, etc.!

**Doctor Jeff** · 03-01-2010, 10:20 AM

Thanks for help. It is better in the bathroom with CFGI but doesn't go away completely.

It may be a pickup/wiring problem. I bought the guitar on Ebay, but it is a brand new guitar with tags and protective plastic still on the pickguard--never been played as far as I can tell.

Of course, with the trouble my house has been giving me lately with plumbing, etc., I'm tempted to blame it all on the house.

I'll try it at my neighbor's later today.

**FatJeff** · 03-01-2010, 11:03 AM

Got any halogen lights about? Those things are murder on a lot of electrical items.

**SamBooka** · 03-01-2010, 01:35 PM

Ok... I feel your pain (I have a fender jazzmaster which are the noisiest pickups on the planet).

1) If you orient yourself in a certain direction and the hum goes away then your ground and mains are fine. Roll off the volume on your guitar. Does the hum go away? If it does then you know it is the guitar and not the amp. A quality guitar cable (not a speaker cable!) never hurts.

2) If the hum gets worse when you take your hands off the strings you know your strings are grounded but could probably use some shielding.

3) All single coils hum. p90s are worse than Fenders (except for JMs which are worse than everything). Some of that you cant get away from without building a faraday cage.

4) As mentioned, fluorecent lights are death. So are dimmer switches.

5) Hopefully Randy C will chip in some of his EE knowledge for things to reduce hum.

6) And if you have your guitar plugged directly into the amp and the amp plugged directly into the wall and you still have the hum it isnt a ground loop.

7) Listen to the youtube demos of the EH Hum Debugger. I couldnt live with it.. maybe for metal but it has a metallic plate-ish reverb sound that would make me nuts.

My house is the worst for hum (making my jazzmaster almost unusable). The JM is wired so when both pickups are on they are humbucking. In this mode it is silent so I know that my shielding is good, my grounding is good, and my mains are clean enough. For fun I bought the little wiring tester for 10$ and it shows everything seems wired ok.

Keep us posted.

**TieDyedDevil** · 03-01-2010, 01:47 PM

First of all, not all hum is "ground-loop" hum. This certainly isn't, whatever the cause. A ground loop is caused when two interconnected pieces of equipment have slightly different ground potentials due current leakage or being on different AC circuits. Since your guitar is grounded only to your amp, what you're experiencing isn't ground-loop hum.

Sometimes your location *is* the culprit. I used to live a few hundred feet from high-tension power lines. That raised holy hell with most guitars. You might experience similar problems if your in close proximity to a power distribution transformer.

Older houses having post-and-knob wiring (typical in the US in houses that were built close to the turn of the 20th century) are also problematic, as the wires are not close enough that the magnetic fields of the send and return paths get a chance to cancel.

Grounding is also important. If you're in an older house, use a grounded outlet and check that the outlet is in fact properly grounded. Get one of those outlet testers with a plug on one end and three lights on the other; it'll cost you less than $5 at most hardware stores.

Here are a few quick checks to help you narrow down the source of the hum:

1. If the intensity of the hum changes dramatically as you move around the room or point the guitar in different directions, then the source is most likely from magnetic fields caused by older wiring or proximity to high-tension lines or a large transformer.

2. If the hum is fairly constant, your amp may not be properly grounded through the 3rd prong of its plug. Check your outlets.

3. If the hum is overpowering and tends toward a buzz more than a smooth hum, you almost certainly have a wiring problem in your guitar or a defective instrument cable.

The EXH Hum Debugger will noticeably alter the tone of your instrument. It's certainly worth a try, but you may not like what you hear.

Ground loop isolators like the you're probably considering from Behringer will do nothing to alleviate this particular problem.

P90s and other single-coil pickups are more susceptible to environmentally-induced hum than are humbucker pickups. If you really like the guitar you might try replacing the pickup with a humbucker pickup in P90 housing. It'll alter the tonality of the instrument, but it'll at least be usable.

Good luck.

**Doctor Jeff** · 03-02-2010, 12:24 AM

Update: I took my guitar to Dave's Guitar Shop and plugged it in. No noise. In fact, it sounded awesome. I ran it through a variety of Fender amps without problems. This leads me to conclude that my house's wiring is crazy or that I must be too close to a power transformer.

Back in their repair area we generated a little buzz by overdriving a small SS amp and tried the Electro-Harmonix Hum Debugger. It worked well at getting rid of the excess sound. You may be aware it gets rid of buzz by generating a low-amplitude delayed signal that cancels out the signal coming from electrical sources. There are normal and strong settings. I could not tell a major difference in sound with the normal setting, particularly with the volume turned down and some reverb added, which is my usual MO.

I bit the bullet and won an Ebay auction for the HD. Hopefully, this will do the trick and solve my problem until I move in July.

**Michael L.** · 03-19-2010, 06:52 PM

What a comfort and help this thread has been! Like Doctor Jeff, I was ready to return my lovely new 5th Avenue Kingpin to the vendor because of excessive hum and hiss. However, trying the guitar out at other locations as suggested in this thread exonerated the P90 pickup. My home is the culprit.
I live in an apartment house built in 1902, and most of the mains wiring is probably the original (DC) one. When you add to that all the noise generated by all the electrical appliances in my own and other apartments, hum unavoidably becomes a formidable nuisance. The power supply in your amplifier will pick up the dirty current and radiate it to the guitar pickup, which will feed it back to the amp and so on and so forth. Shielding the amp has helped some, but nothing short of moving will eliminate the problem totally.
I am going to look for European versions (50 Hz) of hum debuggers, though.

**Doctor Jeff** · 03-19-2010, 07:16 PM

I got the Hum Debugger a couple of weeks ago and it works like magic. Completely eliminates the electrical hum without (to my ears) substantially altering the sound. If I were a Fender tone purist I might quibble, but for jazz with the treble rolled off a bit--sounds fine.

**Jazzophobe** · 03-19-2010, 10:52 PM

Hey, maybe I'll try the hum debugger with all of my single coils...kind of got used to the 60 cycle hum from my Strat and Tele (and even my G&L ASAT)...no need on my humbuckers though (which includes my archtops)...thanks for the tip!

**Michael L.** · 03-20-2010, 03:03 PM

While still studying the range of hum debuggers available in Europe, I made a little experiment to gauge the severity of the mains noise problem in my hum-infested home. Since the mains supply in Denmark usually has no ground, at least not in older housing, the obvious solution was ruled out.
Some years ago, I salvaged a mains filter from a defunct high-end television set, and this filter I have now found and installed in the mains lead to the guitar amplifier, very close to the amp. The effect is gratifying: the filter all but eliminates the annoying hum and hiss, leaving the guitar sound sweet and clean! Only at very high settings of the amp the hum becomes objectionable - but then, very loud playing is hardly for sober home use anyway!
I have attached a schematic of the filter, which is pretty straightforward; for a do-it-yourself person it shouldn't be too hard to assemble such a filter on a PC board. I haven't specified component values since they will depend on local mains voltage and amplifier wattage, but ballpark values may be found here: DIY Netfilters
When playing, I still have to beware of certain angles and to keep my distance to a particular wall obviously concealing a cold war jammer, but otherwise, this filter has cleared up the hum problems with my delicious 5th Avenue Kingpin.
Just wanted to share this with you - hope I'm not merely reiterating old wisdom.

**cosmic gumbo** · 03-20-2010, 06:42 PM

I live in an older house, and this was my fix. I ran a single strand of lampcord from the ground inside the electrical outlet and clamped it to a copper pipe on my baseboard hotwater radiator. Now this outlet has an earth ground and is quiet. Next, a little secret I learned. If you check the specs on some standard type power strip surge protectors, you'll see that they have almost the same audio interference filter specs as a Furman or Monster power conditioner, but way cheaper. This'll help clean up some lighting and magnetic noise. Poor mans fix. All that matters is that I'm hum free.

**Michael L.** · 03-20-2010, 07:19 PM

I envy you: a nice and simple fix when your mains supply has a ground. Ours doesn't, and it is strictly forbidden (with good reason!) to use radiators and cold-water pipes for grounding electrical equipment.
Thanks for the tip on power strip surge protectors; it certainly merits study.