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Post by momojinrobot on Aug 18, 2008 10:51:57 GMT -5
Hi, first post here, hope someone will help me out with this: I have an American Stratocaster, wired this way: www.fender.com/support/diagrams/pdf_temp1/stratocaster/0117400_02C/SD0117400_02CPg2upg2.pdfwww.fender.com/support/diagrams/pdf_temp1/stratocaster/0117400_02C/SD0117400_02CPg3upg2.pdfit's all factory. When I play (guitar volume is always on 10) with the tone pots turned down (aka on 1) the guitar plays fine, with only a light hum and buzz, when switched to single coil position. But when one or both tone pots are turned up the buzz becomes intolerable (especially when in single coil position), and a small part of it disappears if the ground (jack, pots, strings, bridge block...) is touched, the moment I touch it, a click can be heard. It acts like this both if turned into my amp or PC audio interface. Cables and jacks connections are all tested and working fine. Is it normal? I checked all the electronics and wiring with a multimeter except the capacitor, I checked it form being short connected only. All seemed normal, but I'm not 100% sure as I'm no expert. Any suggestion, what could the cause be? here is a photo rapidshare.com/files/138290576/momoamstrat001.jpg.html
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Post by D2o on Aug 18, 2008 12:00:49 GMT -5
Hi momo, and WELCOME! to GN2 Keeping the tone low tends to mask some of the single coil hum, so if you go from 1 to 10 it would be expected that you will allow a lot "more" into the mix - including a lot more hum. However, it gets quieter when you touch anything metal ... that suggests some sort of a wiring / ground issue ... yet you say this is a factory wired guitar ... hmmm ... If you compare the links you have included to this one ( www.seymourduncan.com/support/wiring-diagrams/schematics.php?schematic=3s_1v_2t_5w ) you may find a couple of little differences: 1) the Fender diagram includes a little jumper between the bridge signal return and middle signal return (not the jumper connecting the signal side to signal return side) 2) the hot output to the jack does not come from the middle terminal of the volume pot 3) there is a ground connection from the back of the volume pot to the solder lug I don't know which, if any, would cause the problem you describe, but I seem to recall some discussion a few months back about that solder lug. Hang tight, momo, someone will be along with mo than I got soon enough. DD Edit: Oh! and, of course, shielding will reduce hum substantially.
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Post by momojinrobot on Aug 18, 2008 15:29:06 GMT -5
here is a photo of my guitar wiring rapidshare.com/files/138290576/momoamstrat001.jpg.html Thank you DD842 ver 2.0, much appreciated.
1) www.seymourduncan.com/support/wiring-diagrams/schematics.php?schematic=tone_f_bp changing this has no effect, it just cuts of the tone control for the bridge pickup when selected in single mode (position 5).
2) in the fender schematics the wire isn't shown, connected, but on my guitar the jack's hot wire actually does come from the middle terminal of the volume potentiometer
3) I think you are referring to the 3rd terminal (gnd terminal) of the volume potentiometer being soldered directly to the volume potentiometer's back (in this case the potentiometer's back is the ground)
I have not been able to solve the problem so far, however I noted: There are 2 noise signals: 1) the one which disappears when I touch the ground, this one has very low volume (amplitude). Source of the signal unknown. (the following statement is just an impression: it doesn't change in amplitude while orientating the pickups in space, or between single and dual coil mode) 2) this one isn't affected by touching the ground, this one changes amplitude while orienting the pickups, is much louder in single coil mode, and in dual coil mode it's barely audible, it can be almost totally eliminated orienting the pickups in space. This signal is probably the pickup generated noise. Both signals gets much louder increasing the tones. The 1. is totally inaudible when the tones are turned down (supposedly because it's much smaller in amplitude).
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Post by D2o on Aug 18, 2008 15:51:57 GMT -5
You are welcome, momo. You have stated that "it's all factory.", yet - as you have just mentioned - I see from your picture that the middle terminal of your volume pot does come into play, unlike the Fender schematic I looked at before (unless my eyes were playing games on me). On that basis, and just for the sake of crossing all of the "t"s and dotting all of the "i"s here - is this a direct-from-the-factory, bone-stock, never-been-fiddled-with, american strat, or have you (or possibly someone else) ever desoldered and then resoldered any part of the wiring, in any way? Depending on your answer above - but assuming this is "factory style", but not original, wiring - with respect to the two sources of sound: 1) I dunno ... still sounds a little like ground related, perhaps a cold solder somewhere? (that's why I'm asking if it's "original" or "original style" wiring) 2) is just 60 Hz single coil noise (i.e. perfectly normal, and all but abolished with good shielding - ) DD
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Post by ChrisK on Aug 18, 2008 16:14:56 GMT -5
Note: You don't mention at which frequency(s) the hum occurs. This is general background noise. By adding the mass of your body (thru your finger(s)) to the equation, you are changing the equation. Exactly! AS it changes amplitude while orienting the pickups, is much louder in single coil mode, and in dual coil mode it's barely audible, it's the standard plain old hum picked up by pickups since time began (well, when pickups were invented). It is directional (as the coil is aligned with the source), it is considerable (since there are many turns of wires on those "pickups"), and it goes away with dual coils (presuming that the coils are RWRP with each other - why we invented humbuckers, and call them humbuckers). You may not be aware of it, but two Strat coils that are RWRP to each other are a parallel humbucker when both are selected. Both are attenuated less when the tone is turned up to "10", thus decreasing the effect of the high frequency cutting filter. Now that I have restated the obvious (although your guitar SHOULD have these problems, hopefully to a lesser degree), many of the things pointed out by DD842v2 are in play. Are these problems the same as they always were or are they recently new to the guitar? Either way, there are things that can be tested and done to help minimize noise pickup. Some are around the question of the adequacy of the grounding within the guitar and others relate to better internal shielding and the use of better cables. More info please!
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Post by ChrisK on Aug 18, 2008 16:19:32 GMT -5
I can't see the pics since "rapidplay" is blocked by corporate. However, if the middle terminal (as in wiper) doesn't come into play (which one might presume means used), it ain't a volume potentiometer or a volume rheostat, just a mechanical thing holding up a knob as a decoration! ;D ;D
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Post by momojinrobot on Aug 19, 2008 0:49:44 GMT -5
DD842 ver 2.0 thanks again for the reply, yes someone could have desoldered and then resoldered parts of the wiring however I resoldered all the solders in fear there could be a cold solder and checked all with the multimeter, but haven't found anything wrong maybe the capacitor or the pots are faulty maybe I should think of keeping it like that until I decide to replace all the electrics I could always attach a wire to my body while playing...
Thanks ChrisK, much appreciated, cos of your corporate I've sent you a mail with both photo and audio, for the rest of you who can use rapidshare here are the audio files and photo in zip: rapidshare.com/files/138340169/momoamstrat.zip.htmlthe audio files are pretty self explanatory, however: volume, and tones on 10, guitar connected directly into, for instruments, PC audio interface input, recorded with Adobe Audition 3 dualcoil.wav: The file starts (and ends) without me touching the ground, after that i repeatedly touch an release the ground, part of the noise is clearly disappearing when i touch the ground and appearing again when i release. singlecoil.wav: same, just the coli hum is much higher and becaouse of that the changes are less noticiable. EDITIf someone want to ask specific questions or request electric measurements, please don't hesitate! EDIT 2I noted that when I turn up the volume pot from 1 to 8 the electric resistance measured between the hot and gnd terminals of the guitar jack vary from 24Ohm to 61kOhm, and from position 8 to 10 it vary from 61kOhm to 6, 3, 6.2, 3.5, 7.5kOhm (depending on the pickup switch position). Is it normal for the pot, resistance, to act so nonlinear?
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rbkxiiowe
Apprentice Shielder
Posts: 45
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Post by rbkxiiowe on Aug 19, 2008 4:29:14 GMT -5
Hi momo.
Yes it is usual for the resistances to change like this. Volume pots are almost always a LOG pot, or logarithmic taper potentiometer. This is because our ears hear changes in amplitude in this way, so 10 on a LOG pot sounds twice as loud as 5. (perhaps someone else can link this in with why dB is a logarithmic scale?).
LOG pots are also sometimes called audio pots. If you look on the back of your volume pot it may say somthing like 'A250K' ('A' for audio, '250K' for its maximum resistance).
I assume you meant 6.1kOhm not 61kOhm? When you've got your volume and tone controls all the way up and are measuring resistance across the tip and shaft of the cable, you're pretty much measuring the resistance of your pickups.
6, 3, 6.2, 3.5, 7.5k sounds about right. In positions 2 and 4 on the selector you're measuring two pickups in parallel (1/R = 1/R1 + 1/R2).
Hope this helps.
Cheers.
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Post by momojinrobot on Aug 19, 2008 8:05:23 GMT -5
when i wrote 61kOhm i meant 61kOhm (sixty one kOhm) it goes up from 24Ohms to 61KOhms and than to 7.5~3.5 EDITit seems it is just how it have to be : )EDIT 2I've unsoldered all the components, tested them, all seems fine, but somehow I'm getting a very low output from the coils now. Somehow more and more issues has started crowding. desperate
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Post by D2o on Aug 19, 2008 11:55:23 GMT -5
No, no, no, my friend. Not desperate ... view this is an opportunity! Place your ear up to the computer screen ... can't you hear it? ... Your guitar is calling out to the QTB mod, which is calling out to your computer ... your guitar is talking to you, man! ... shield me ... shield me ... Okay, well maybe it isn't ... but I still think that if you're in there re-soldering everything anyway (which may be assisting you in your frustration), you might as well shield your guitar, at the very least. And, while you're in there, why not also wire it according to the instructions - it will likely solve all of your problems at the same time. DD P.S. momo, can you do me a fave? - I've noticed that you sometimes go back and edit previous posts to update us. It would be better if you just include new info in a new post, so there is no risk of one of us missing it. Thanks, buddy
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Post by ChrisK on Aug 19, 2008 11:55:52 GMT -5
Clues: .....between the hot and gnd terminals of the guitar jack..... ......depending on the pickup switch position...... Reference Article: Discerning Paralleled ResistancesThings are acting quite normal for a circuit, not a single component. As you read the reference article, you'll see that the volume pot has two circuit branches. One is from the pot wiper to ground and the other is from pot wiper to pot hot terminal to pickup(s) to ground. These two branches are in parallel. Now, looking at the values from the "10" position, your pickups have the following approximate (you only indicate two significant digits) values of resistance; Neck - 6K Ohms Neck parallel middle - 3K Ohms Middle - 6K2 Ohms Bridge parallel middle - 3K5 Ohms Bridge - 7K5 Ohms 6K in parallel with 6K2 = 3K049 and 6K2 in parallel with 7K5 = 3K394 Hey, close enough! Again, these are approximate since the volume pot is in parallel with these when at "10". Per the reference article, 61K Ohms as a maximum value is normal. This indicates that each branch of the resulting volume pot and selected pickup(s) circuit has a maximum branch value of 122K Ohms (two 122K in parallel = 61K), and the maximum value of the pot element and the pickup is around 244K (122K + 122K) Ohms. This is quite normal for a 250K Ohm (+/- 30%) pot.
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Post by newey on Aug 19, 2008 15:20:29 GMT -5
MJR-
The first Rule of Holes:
When one finds oneself in a hole, quit digging!
By your posts, you have now resoldered all the joints once to check for a cold solder joint, and once again to check each of the components, and now you're having added problems.
It's time to put the soldering iron down and do some troubleshooting. If you keep changing all the variables, we'll never be able to help pin down the problem.
Now, what is the state of your guitar currently? Is it all together, but giving low output, or is it still apart (and you measured "low output" with a meter?)
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Post by momojinrobot on Aug 20, 2008 14:23:35 GMT -5
I stooped. I've my guitar all together. It's a '03 fender strat, never used or played until 1 week ago, all was factory. I have a Traynor YCV50BLUE amp. www.traynoramps.com/products.asp?id=318&cat=63&type=3 When plug the guitar in the PC audio device: -get high noise -it's not 60Hz hum but all sort of frequency -there is no sign of 60Hz hum (or it's very low) -it get worse when I turn up tones -if I orient the guitar in space certain ways the noise attenuate to very low levels -the noise is much lower in dual coil mode (but again to loud to be normal) -when I touch the ground (something metal) on my guitar a loud "click" can be heard, and the noise changes in part -it's the same with all of the pickups When i plug it in the amp: -all as above + -if I touch the strings with where my skin on my arm is thinner I can feel something piercing my skin, probably electricity. It hurts a little.
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Post by newey on Aug 20, 2008 15:25:36 GMT -5
Did you purchase this new recently? Is it perhaps still under warranty?
This should definitely not be happening.
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Post by ChrisK on Aug 20, 2008 15:41:17 GMT -5
I don't know where you live, but this all may indicate a mains safety grounding issue. That's assuming that your country HAS a safety grounding method. I solve noise issues this way; shield the internal cavities on guitars. I solve safety issues this way; use RF links to the amp(s). Only lightning can jump that distance! One of my sister's friend's sons was getting shocked when he played his guitar barefoot. His uncle told him to wear his shoes. I told him to get his amp/outlet fixed.
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Post by D2o on Aug 20, 2008 15:45:38 GMT -5
momo,
I don't know if I ever mentioned that I couldn't tell much from your earlier audio recordings.
If your strat is not under warranty, you know what I would do (especially considering you've got a tube amp). That would also end up dispensing with that "solder lug" that goes to the back of the volume pot ... something about that bugs me.
Back to point: noise may be one thing, but shock! is another. Newey is right - if it is under warranty, take it back.
The following is really just out of curiosity: how much distance do you have between the strings and the pickups (i.e. how high are the pickups)?
DD
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Post by ChrisK on Aug 20, 2008 16:58:02 GMT -5
If you took it apart and resoldered the wiring, it is no longer under warranty.
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Post by D2o on Aug 20, 2008 17:08:05 GMT -5
Good point, Chris. momo, I still say you should view this as an opportunity. Why, if I hadn't screwed up my own electric guitar, I would never have had the opportunity to participate in this forum and get mine fixed and learn how to screw up other people's guitars help other people with their guitars. You can do the same! Baptism by fire, my friend - QTB ... it's fairly easy and fairly effective - and we'll help if you hit snags. DD
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Post by momojinrobot on Aug 20, 2008 17:23:50 GMT -5
it's 2nd hand, no warranty
I experienced the shocks only earlier today. It was a faulty outlet to double outlet extension into which i used to plug my amp.
I removed it and the shocks are gone. However all the other issues remain, the noise, ground touching clicks etc.
I'm gonna ATB (Abate the Beast) and see if it works for me.
If anybody have some other ideas what could the causes be (else of "just your local radio station"), let me know, it'll take me a week to gather all the components to QtB.
for the distance between the picks and strings i tried to lower picks under the guard but it's no use
generally the first is leveled with the pickguard and the other two follow fender standard to mach the distance to the wires.
Thank you all guys!
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Post by D2o on Aug 20, 2008 18:11:07 GMT -5
No, not likely the radio station. But what is your playing environment? When you plug into the PC, are you near a CRT computer minitor? Fluorescent lighting? Dimmer switches, etc?
By the way, you still haven't told us where you're from ... North America has 60 Hz hum to deal with, that's not necessarily so with other countries (although the idea behind the shielding is the same regardless).
DD
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Post by momojinrobot on Aug 21, 2008 13:00:01 GMT -5
in the post before i mentioned the clicks persists but I lied, they are gone with the shocks, only the noise that can be quieted orienting is still present
as for my playing environment, it's actually very electromagnetically noisy, therefore I hope QtB will help at least a little bit.
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Post by D2o on Aug 21, 2008 13:15:11 GMT -5
in the post before i mentioned the clicks persists but I lied, they are gone with the shocks, only the noise that can be quieted orienting is still present I had no clue what the heck those clicks were about, so hopefully it was just a result of little old you being slowly electrocuted. ;D I'm glad the shock, in particular, is gone and I'm glad the clickity-clack has not come back. Did I mention that Hallmark has made it clear that they won't be using my rhymes in any of their cards? Yes, it's a very rewarding mod for a number of reasons: 1) it provides additional shielding to reduce the hum you have mentioned. 2) star grounding further reduces the amount of hum that gets into the signal path. 3) the .33uF 400V capacitor isolates as many touch-points as possible in case your TUBE amplifier fails and tries to electrocute you. Go to it! DD
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Post by momojinrobot on Aug 26, 2008 8:22:23 GMT -5
I found myself with one 0.022uf and one 0.33uf capacitors of this kind, www.wima.com/EN/mks4.htmboth 400V are they any good, or should i buy something else?
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Post by D2o on Aug 26, 2008 9:02:57 GMT -5
I found myself with one 0.022uf and one 0.33uf capacitors of this kind, www.wima.com/EN/mks4.htmboth 400V are they any good, or should i buy something else? Hi momo, I think they should be fine, although you may be better off with their film/foil ones (polypropylene ones are probably the best bet): www.wima.com/EN/products_pcm7_5_foil.htmAre you in Germany? If so, try googling "Orange Drop" on www.google.de/ DD
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Post by momojinrobot on Aug 26, 2008 10:18:25 GMT -5
I opted for the Orange Drops www.sbelectronics.com/images/PDFs/716p.pdfno wonders the polypropylene 716P series is better, they are twice the price of the regular 715P i bought one 0,022uf and one 0,22uf, both 716P 600V 5% 85C the 716P comes with copper radial leads, wow! (do I need this ? probably no, but when you love the sound of your guitar, you'll rather starve then play on cheap capacitors! ) Thanks for the information!
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Post by D2o on Aug 26, 2008 10:51:44 GMT -5
I opted for the Orange Drops www.sbelectronics.com/images/PDFs/716p.pdfno wonders the polypropylene 716P series is better, they are twice the price of the regular 715P i bought one 0,022uf and one 0,22uf, both 716P 600V 5% 85C the 716P comes with copper radial leads, wow! (do I need this ? probably no, but when you love the sound of your guitar, you'll rather starve then play on cheap capacitors! ) Thanks for the information! You are welcome. There is no question that they are good capacitors and so you have peace of mind (not to mention cool looking orange caps under the hood). ... No, you don't "need" any of this cool stuff ... but for twice a relatively small price and no extra effort to buy them, might as well right? DD
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Post by ChrisK on Aug 26, 2008 12:43:45 GMT -5
While these caps are indeed orange, bear in mind that "Orange Drop" brand capacitors are made by Vishay/Sprague. Orange Drop CapsWhile polypropylene material capacitors are to be preferred for audio signal circuit use (such as tone controls) they aren't needed for the 0.33 uF 400 VDC isolation cap. As long as the isolation is, uh, isolating, we don't care much as to its fidelity.
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Post by D2o on Aug 26, 2008 12:50:21 GMT -5
Infidel! Chris, yer freakin' me out with the invisible user status, man! ... I mean, "virtual, virtual" man! ... ;D DD
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Post by momojinrobot on Aug 26, 2008 14:04:34 GMT -5
Orange Drop caps are always to prefer, no matter what you use them for, tone control or as earrings, they are always the coooolest...! All others are... unseaworthiness! I'm not high and I'm definitely not listening to Jimi while writING THIS, OK!?! OH! Driving South is starting, my favorite, sHHhh!!!
SB Electronics is and was the only manufacturer of Orgies Drop... Orange Drop what did I said...
you know what I'm talking about...
that's what I said Orange Drop...How does shielding the front cavity with copper tape affect the acoustics of the wooden body, and how would it be replacing the stock pickguard with a copper one?
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Post by D2o on Aug 26, 2008 14:25:01 GMT -5
High, momo What is this ... Welcome Back, Kotter? Shielding doesn't affect the acoustics of a solidbody guitar made of wood. However, one should refrain from shielding one's acoustic guitar made of wood. How would it be replacing the stock pickguard with a copper one? It could be shiny, or expensive, or ... ?? ... see the copper pickguard discussion here. DD
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