Members Misha Posted July 20, 2015 Members Share Posted July 20, 2015 I got a Godin Gore CT P90 recently. I fell in love with it in a music shop and gave a deposit on it telling them I would come back. A few days ago, the store called to tell me that the guitar was now on sale for 555$ instead of 794$ (+ taxes!) I didn't get it the weekend before because my boss asked me to do some overtime! It's the best overtime I have ever done! Double rate for the overtime plus the guitar I want gets on sale! .png' alt='16x16_man-very-happy.png.58f4fc7892e8041ddc6575c8d5db3ad6.png' alt='very-happy'>.png'> Well, now I have the guitar at home and there's a weird thing happening with the P90 pickups: I have to keep the guitar at 90 degrees from the amp to reduce the hum while I play !!! ??? !??? When I think about it, that's how I was, compared to the amp, in the store the day I tried it and I was surprised how quiet the pickups were. At first when I came home with it I was discouraged. Then I set the fridge a bit lower and it made a difference. Then I turned my back to my computer desk and bang! The hum went back to the same level as in the store! Anything I can do to solve this little problem or is it how it goes with P90 pickups ? A part from that, I love the guitar! The fact that it's chambered make it very good for my old back! ------------------------------------------------------------------------------------------------------------------------------------------- Edit: I have all kind of trouble posting! I can't even type any text without using the edit button! I can't type text to reply either !? Link to comment Share on other sites More sharing options...
Members wankdeplank Posted July 20, 2015 Members Share Posted July 20, 2015 If you are around fluorescent lights, that would be a contributing factor. Aside from that, like other single coil pickups, some are just noisier than others. Link to comment Share on other sites More sharing options...
Members Misha Posted July 20, 2015 Author Members Share Posted July 20, 2015 There are no fluorescent lights in my apartment but I'm wondering if the apartment above or under me couldn't have some... Link to comment Share on other sites More sharing options...
Members wankdeplank Posted July 20, 2015 Members Share Posted July 20, 2015 Very possible. Wish I could be more help. Beautiful guitar, sure you'll figure something out for home use, and hopefully better away from home. Link to comment Share on other sites More sharing options...
Members Grant Harding Posted July 20, 2015 Members Share Posted July 20, 2015 Nice guitar!! If you end up not being able to stand the noise you can upgrade them for some noiseless P90s, which are now awesome. Link to comment Share on other sites More sharing options...
Members WRGKMC Posted July 20, 2015 Members Share Posted July 20, 2015 If the Single coils have no hum bucking in the center position they can act like antennas to pick up localized AC emissions. When the guitar is turned and the hum fades its simply the angle the pickup coils are to the source of radiation. You found a null point wherethe hum is minimal. Its really not that mysterious however. If you've ever used a portable radio you often have to turn the radio to find the best reception (strongest hum with a guitar) The opposite would be to turn the radio or move the aerial for the weakest reception which is exactly what you're doing with the guitar. The fix is to make sure you're using 90% shielded cables. Budget cords are often 70% and do a poor job blocking hum. The other items that may help is to add grounded shielding in the guitar. Some P90's use unshielded leads and hum badly. The cavity can often be improved with grounded shielding. You have to remember these kinds of pickups were originally designed for Jazz guitars which were intended to be run clean. When they are gained up, any weakness in the shielding will allow hum to leak in and be amplified by the multiple gain stages in a gain pedal or amp drive channel. You may also need to minimize the amount of gain you use and to find the source of hum where you have the amp. Someone mentioned Fluorescent light which is a big one. CRT computer screens or Televisions with CRT screens have high voltage fly back transformers which emit AC waves. They may not even be in the same room. They can be in the next room or on the same AC line. You can have a poorly grounded outlet too. Try the amp in a different room and see what happens. Allot of hum reduction comes down to process of elimination so you have to try a few things and evaluate weather things get better or worse. Link to comment Share on other sites More sharing options...
Moderators Ratae Corieltauvorum Posted July 20, 2015 Moderators Share Posted July 20, 2015 The best way to screw around with P90s are dimmer switches. Link to comment Share on other sites More sharing options...
Members 1001gear Posted July 20, 2015 Members Share Posted July 20, 2015 Edit: I have all kind of trouble posting! I can't even type any text without using the edit button! I can't type text to reply either !? Nice guitar. Firefox w/ Win7 seems to work best. If you are outside the US, setting the language (don't know exactly where this is; it's not the keyboard setting ) to US English has worked for Internet Explorer. Some people are able to comment on posts even if quotes and replies don't work. Directional hum might be a function of the radio fields in your area. It is in mine. PUs facing north or south works for me at home. Link to comment Share on other sites More sharing options...
Members gardo Posted July 20, 2015 Members Share Posted July 20, 2015 I had a guitar with a similar quirk . Where I stood relative to the amp and which way I faced effected the buzzing. So I learned where to put the amp where to stand and which way to face. Not always practicle but that's what i did. By the way I love hering stories about unforseen circumstances leading to a better deal . Link to comment Share on other sites More sharing options...
Members Danhedonia Posted July 20, 2015 Members Share Posted July 20, 2015 You don't really have a problem with the pickups because they're P90's; you have a problem with electromagnetic interference. If directionality alters the amount of hum, it's highly likely that you have poorly shielded electricity in your home. You already said 'apartment,' and so I'm going to guess that's the case (as apartment buildings are usually constructed with low cost options). Here's an easy way for you to save yourself an awful lot of stress and time: take the guitar to a relatively stable electrical environment (a friend's garage in a standalone home, perhaps) and see if you get the same noise. In all likelihood, you will not - and now you know the issue is the wiring in your place, not the guitar. Monkeying with your gear to accommodate your apartment's issues just seems like throwing good effort / time / money after bad, IMO. Unless you know you're going to stay there for years and years. Link to comment Share on other sites More sharing options...
Members Misha Posted July 20, 2015 Author Members Share Posted July 20, 2015 Thank's for the info! The pickups are Seymour Duncan pickups. They sound very good. I would like to keep them but if I have no choice, I'll swap them! Here are the specs of the guitar: SPECS High-Gloss Maple Carved Top.Chambered Spanish Cedar body.Mahogany set-neck.Rosewood fingerboard.Large dot fingerboard inlays.Graphtech ResoMax Wraparound bridge system.3-way Toggle Switch, 2x Volume, 2x Tone.12" (300 mm) fingerboard radius.24 3/4" (629 mm) Scale.1 11/16" (43 mm) nut width.Colors: Black GT & Sunburst GT (GT = Gloss Top).Pickup options:2x Seymour Duncan P90 (Neck: Vintage SP90-1 / Bridge: Custom SP90-3). Link to comment Share on other sites More sharing options...
Members Misha Posted July 20, 2015 Author Members Share Posted July 20, 2015 I think I'm going to ask a tech to make sure it is grounded/shielded properly. Also my cables are not of the best quality. I could get better ones. In the music shop I tried the guitar with a Fender Champion 40 which is a relatively inexpensive amp and it sounded very good with almost no hum. The salesman was as surprised as I was by how quiet the pickups were, but we probably put the guitar and the amp in a sweet spot by pure coincidence! Link to comment Share on other sites More sharing options...
Members Misha Posted July 20, 2015 Author Members Share Posted July 20, 2015 No dimmer switches in my apartment! One less thing to take care about ! Link to comment Share on other sites More sharing options...
Members Misha Posted July 20, 2015 Author Members Share Posted July 20, 2015 Sometimes it works, others: no! At first, it would not work at all with Chrome, my favorite browser. It was a bit better with Internet Explorer. Today it seems to be working. When I shut down my computer last night I saw a message saying there were 55 Windows updates to install... Link to comment Share on other sites More sharing options...
Members Misha Posted July 20, 2015 Author Members Share Posted July 20, 2015 It would be a bit more pratical if I could at least face my computer! ;-) Right now, it's not very practical to watch guitar lessons on line! lol About the deal, I'm not a very lucky person, usually, but that phone call was a very, very pleasant surprise and it made my day! Link to comment Share on other sites More sharing options...
Members Verne Andru Posted July 20, 2015 Members Share Posted July 20, 2015 If the pickups don't hum-cancel in the middle position, and they are real P90's, you can easily mod one pickup to be RWRP to the other. Pickups solo'd will be the same, but running them together they become a "humbucker" and most noise problems should diminish considerably. Link to comment Share on other sites More sharing options...
Members WRGKMC Posted July 20, 2015 Members Share Posted July 20, 2015 I think I'm going to ask a tech to make sure it is grounded/shielded properly. Also my cables are not of the best quality. I could get better ones. Try the cords first. You'll probably get the best bang for your buck with good cable shielding. Your cheap stuff often has holes in the braiding that let hum in. You probably used a good cord at the music shop or the amp wasn't gained up as high so was less likely. They probably have a good electrical environment too in the store too. If you used a guitar with Humbuckers prior to buying this one you may not have noticed the issue at your apartment because most of the hum was being canceled by those pickups. From there it can be small degrees, each making the problem improve. You'd think they would use shielded wire to the pickups, but there are some brands that do use single conductors like Fender Pickups. I converted a few sets I bought from single to shielded. If they are Gibson type they should be shielded well. If the cables and rest of the guitar wiring is good, bout the only thing you have left is adding shielded covers that are grounded. You can add copper foil to the inside of the plastic covers or buy metal ones. Both would require a ground wire to them.I've also seen plenty of sloppy wiring at switches and pots where they fail to keep the hot leads short and could be improved by keeping the shield up close to the hot wires solder joint. Conductive paint of copper foil in the cavities can do wonders too. Like I said, any one of these may not have a huge impact but they are additive. In an apartment your neighbors may have older CRT televisions or computer screens going so you may never get rid of the problem completely. If you can reduce it and make it tolerable, then you may wind up with the guitar dead silent in a good environment. You probably used a good cord at the music shop or the amp wasn't gained up as high so hum was much less likely. They probably have a good electrical environment there too in the store too. The directional thing is almost always between the amp and guitar. Be sure the amp is properly grounded too. Your shielding conducts hum to ground and if the shielding isn't grounded it winds up making hum issues worse. Instead the hum being drained off to ground the shield winds up collecting and injecting hum into the signal wire. Just rule the issues out one by one. Just moving the amp to another outlet can often times be a cure. Link to comment Share on other sites More sharing options...
Members gardo Posted July 20, 2015 Members Share Posted July 20, 2015 You might also be getting interference from your neighbors.Let them replace all of their lightbulbs with compact flouresents and watch what happens Link to comment Share on other sites More sharing options...
Members gardo Posted July 20, 2015 Members Share Posted July 20, 2015 This is why I don't own any P90's Link to comment Share on other sites More sharing options...
Members thatsbunk Posted July 20, 2015 Members Share Posted July 20, 2015 Do you use any type of power cord strip to plug your amp into? We had a problem forever where we practice, & I thought it was because of the florescent lighting & dimmer switches there. You could only position yourself in certain places in the room where the hum was tolerable (& only facing in certain directions with the guitar). It got to the point where I wouldn't bother bringing any single coil guitars with me. Turns out we discovered (by accident) that the culprit was a power strip that most of our stuff was plugged into... Link to comment Share on other sites More sharing options...
Members thatsbunk Posted July 20, 2015 Members Share Posted July 20, 2015 maybe i'm a newb, but how do you do this without re-winding the pickup? do you just reverse the pickup leads? Link to comment Share on other sites More sharing options...
Members Verne Andru Posted July 20, 2015 Members Share Posted July 20, 2015 It's a bit more complicated than that. It involves taking one pickup apart, physically flipping the magnets [a P90 has 2] then putting it back together. That gives you RP [Reverse Polarity]. Next is the RW [Reverse Wound] which involves reversing the 2 leads. So, if your pickups have Black for ground and Red for hot, find where they are soldered to a component [pot, switch, etc.] and reverse where the leads are attached. Google is your friend. Another alternative is to buy a set of RWRP replacements. I recently did this to my Epiphone Wildkat and love the results. There are a really nice sounding set of P90's and run dead quiet with both of them on. Other things to do to get the best of the best signal isolation is to use a star ground and shield the pickup cavities to create a sort of Faraday cage. I go into this on a Fender eMando over at Mandolin Cafe: http://www.mandolincafe.com/forum/showthread.php?96735-Fender-eMando-Blacktop-make-over Link to comment Share on other sites More sharing options...
Members Verne Andru Posted July 20, 2015 Members Share Posted July 20, 2015 Link to comment Share on other sites More sharing options...
Members DeepEnd Posted July 20, 2015 Members Share Posted July 20, 2015 Happy New Guitar Day and congratulations on the bargain. I don't have anything to add beyond what's already been said. Try a better cable and maybe improve the shielding for the cavity and pickguard. Lots of vids out there that will show you how to do it yourself. Link to comment Share on other sites More sharing options...
Members Misha Posted July 20, 2015 Author Members Share Posted July 20, 2015 My cousin gave me some furniture, today. I decide to put my pedals and amp (Yamaha THR-10) on the service table (désserte in French, not sure in English), and the noise went away! (And yes, my twenty-something pounds ginger cat is sitting on the table if you look at the pictures in the first post... The poor little thing does that sometimes!) I put a power bar between the wall and the cords because I needed a longer cable! For now, it seems that I'm fine! Thank's to all of you for your help! If I have further problems, I'll come back to that post and try what you suggested me! Maybe it's something in someone else's apartment that makes it Noisy, sometimes! For now, I'm good to go! _____________________________________ By the way, I can't post an answer, I can only "reply" to an answer... I can't post pictures today or anything! Link to comment Share on other sites More sharing options...
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