Asher Guitars WD Music Products Amplified Parts Mod Kits DIY Nordstarnd Pickups Warmoth.com Reiland Pickups
Asher Guitars WD Music Products Amplified Parts Mod Kits DIY Nordstarnd Pickups Warmoth.com Reilander Pickups
Asher Guitars WD Music Products Amplified Parts Mod Kits DIY Nordstarnd Pickups Warmoth.com Reilander Pickups
Join TDPRI Today

Why would middle position have more noise?

Discussion in 'Tele-Technical' started by jwp333, Mar 19, 2017.

  1. jwp333

    jwp333 Tele-Holic

    643
    Jul 17, 2013
    Richmond, VA
    I've got a G&L ASAT with the big MFD's that I don't play a lot. I took it out this weekend and noticed some extra high pitched hum/electrical noise in the middle position, but only barely noticeable in the neck or bridge position. I touch the strings and it goes away. I roll off the highs with the tone control and it goes away. I assume I have a ground problem but it seems strange that its more pronounced in the middle position (usually hum cancelling). Is that a sign of a particular problem? Any thoughts?
     
  2. fidopunk

    fidopunk Tele-Meister

    317
    Nov 23, 2008
    Charleston, WV
    Have the pickups been replaced? They need to be RWRP for noise cancelling in the middle position.
     
  3. dsutton24

    dsutton24 Poster Extraordinaire

    Dec 29, 2010
    Illinois
    As my colleague fidopunk noted, in order for the middle position to be noise canceling, one pickup has to be RWRP in relation to the other. It's easy to check, hold a compass up to each pickup. If the north side of the needle is attracted to one pickup, and the south is attracted to the other, you've got an RWRP relationship, and they will be noise canceling in the middle position.

    If they're not RWRP, the middle position will be noisier than a single pickup position. The reason is easy, more pickups means more noise. I'm betting this is what you have. The fact that the noise goes away when you're touching the strings means that everything is wired correctly, and there are no wiring problems.
     
    Piggy Stu likes this.
  4. Forum Sponsor Sponsored posting

  5. tessting1two

    tessting1two Tele-Meister

    151
    Apr 13, 2014
    Southern California
    Did you play any other guitars at the time and were they problematic too? Sometimes power, lighting, and RF issues in the room will release gremlins to torment our humble guitars. I'd try another room/circuit/amplifier and see if the noise follows.
     
  6. Tony Done

    Tony Done Friend of Leo's

    Age:
    72
    Dec 3, 2014
    Toowoomba, Australia
    Can you guys just clarify something please, as I haven't paid any attention to it myself. My understanding is the RWRP (humbucking) will defeat mains hum, but you need shielding to defeat rf (near-white) type noise. The OP seems to be talking about rf, since it will roll off with the tone control, so is this related to RWRP?
     
  7. jwp333

    jwp333 Tele-Holic

    643
    Jul 17, 2013
    Richmond, VA
    I'm the OP, and to clarify, I've had some similar noise from a telecaster also in that room. Haven't noticed noise with one strat. That's it for my pure single coils. It is a very high pitched noise and faint noise, not a loud buzz. There is a dimmer switch in the hallway outside this room. There is a flourescent light bulb in the overhead. There's also a phone which sends a wireless signal to other phones in the house (haven't heard of that causing rf interference but I thought I'd mention it).

    Was curious about the comment about touching the strings. That would be a sign that the wiring is okay and not the issue?
     
  8. sjtalon

    sjtalon Poster Extraordinaire

    >>Was curious about the comment about touching the strings. That would be a sign that the wiring is okay and not the issue?<<

    As far as the GUITAR wiring, that is a good sign. Means the bridge and therefor strings are to ground. So when you touch the strings, it helps subdue some outside noise as your body acts as a shield.

    Also a sign the jack is wired correctly as if the output jack got wired backwards (positive to negative wise), noise would increase when you release anything metal there (control plate, strings).

    That real high pitch makes me think you have no issue with this geetar, just that the two coils in that one are better antennas than your others.:)

    Go to the garage, or another room, or house and it will probably be gone too.

    I would think the pickguard has shielding on it, that does quite a bit of good, acually moreso than any body cavity shielding job. Take a look. If there is none, just put some aluminum foil ( trace it with the pickguard and cut it out, glue it on) on the back. Make sure you ground it.
     
  9. dsutton24

    dsutton24 Poster Extraordinaire

    Dec 29, 2010
    Illinois
    That's a common misconception. Noise is noise, humbuckers or RWRP combination single coils do not differentiate between 60hz or 120hz noise, and any other audio frequency noise, such as hash caused by florescent lights or neon signs. Pickups may be less effective as a noise reduction apparatus as frequency goes up due to their inductance. I haven't devoted any math to the problem, it's just a hunch.

    There's nothing in a pickup that makes them selective as far as 60 and 120hz signals go, be that signal noise or music.

    White noise is just random frequency noise, and can exist from d.c. to daylight. If it falls in the audio range humbuckers or RWRP single coils should cancel it just fine, except possibly as noted above.

    For some reason guitar people seem to call any noise that does not fall into the 60 / 120hz category r.f. R.f technically starts at 3khz which is roughly G four octaves above middle C. If you're getting noise in that kind of audio range, it could be r.f. More commonly If you've got an old amp that plays whatever the local AM radio station is playing at the moment, that's r.f. interference. It takes a number of things for this to happen, amplification, detection, etc. It could happen in a guitar, but it'd be unusual. You can get detection across a bad mechanical joint. There used to be a variant of the old crystal radio that used a blued razor blade or a rusty nail as a detector. It was fiddly as heck, but it could be done. In general, though, if it's happening in a guitar, and you can hear it, it's just audio spectrum noise, not r.f.

    The above is somewhat simplified, but is accurate as far as real-world issues go. It's based on a lot of years worth of experience, including experience as a broadcast engineer. R.f. is a very different world that we deal with in audio and musical instruments. There will be somebody that will come along any minute now with graphs proving the above is wrong. That's okay.
     
  10. Tony Done

    Tony Done Friend of Leo's

    Age:
    72
    Dec 3, 2014
    Toowoomba, Australia
    Thanks. It reminds me that I've still got ideas about acquiring/biulding a white noise generator for testing pickups and shielding. Any suggestions?

    I've never had a major problem with mains hum but white-type noise can be an issue. I/ve wondered if differences in experience are due to the difference in mains voltage between Oz and the US.
     
  11. dsutton24

    dsutton24 Poster Extraordinaire

    Dec 29, 2010
    Illinois
    The classic white noise generator uses a tunnel diode or zener diode as the noise source. I haven't studied this very closely, but at a glance it might be a good place to start:

    https://electronicsproject.org/white-lf-noise-generator/

    Funny... autocorrect wants to turn 'zener' into 'sneer'.
     
  12. Tony Done

    Tony Done Friend of Leo's

    Age:
    72
    Dec 3, 2014
    Toowoomba, Australia
    Great, thanks. A nice little electronics project.
     
  13. Tony Done

    Tony Done Friend of Leo's

    Age:
    72
    Dec 3, 2014
    Toowoomba, Australia
    This might interest you. It is a screen shot of a sound file that I posted a couple of years ago. Here is the accompanying text:

    "This is a sound clip of an SD jazz pickup with series/single parallel switching. The first half is rf noise greatly amplified, in three segments. The first segment is series, the loud second segment is single and the last quiet segment is parallel. The 50-cycle overlay can also be heard in the single segment. The second half is a note being played in the same three switch positions. There is not much difference in tone, but the recording is compressed and fairly low-fi. Through an amp, the series position is louder and smoother, but the single and parallel are very similar in both volume and tonal quality."

    [​IMG]

    Both series and parallel humbucking configurations clearly produce less noise of any kind that single. Unfortunately I don't have a non-humbucking pair for comparison.
     
IMPORTANT: Treat everyone here with respect, no matter how difficult!
No sex, drug, political, religion or hate discussion permitted here.