Conference napalm::guitar

    How loud are you playing?
    What kind of guitar is it?
    What kind of equalisation are you using on your amp?  
    Are you using distortion at all?
    
    craig

    Uncontrollable feedback is generally caused by a problem with
    a microphonic pickup. The cause is usually a loose winding
    or pole piece inside the pickup. Potting with wax often eliminates
    this problem, however it is usually easier to replace the pickup
    with an equivelant replacement. 3 single coil pickups sounds like
    a Fender Strat clone. If so, Strat pickups are available from
    a multitude of manufacturers starting around $25.00 and up.
                             
    One would think the treble pickup would be more likely to cause
    feedback, but this is not necessarily the case. The pickup with
    the microphonic problem could be any one of the three. If the middle
    pickup was microphonic, it would affect 3 of the 5 positions on
    your selector switch. 
    
    If you do end up replacing a pickup make sure the one you buy is
    potted. 
    
    Mark.
    
    

    
    
    	I replaced a coupla of single coil pickups in my Mustang when
    I (ahemmmm...) modified it recently!  The originals were noisy and
    produced feedback early.  I bought the new ones EMG Selects from
    Stewart Macdonald for 17.50 a piece and I'm very satisfied.  They
    are quiet, and don't feedback as soon.  If I had it to do over again,
    I'd probably just replace the bridge pickup and keep the Fender
    single coil in the neck position (or maybe I could make a Humbucker
    out of the two single coils that I've got... hmmmm would that
    work????).
    
    Steve

    
    Humbuckers are indeed pairs of single coils, but to get humbucking
    action from a pair of existing single coils, you need to rewind
    one of them in a backwards direction, then connect the two in parallel
    but out of phase.  The reversed winding means the *signal* ends
    up back in phase but the induced hum is out of phase, and thus is
    largely cancelled out.
    
    Just connecting two single coils out of phase will give you humbucking,
    but also that thin "out of phase" sound.  C'est la vie.

    RE: .1
      Loudness level: The hum occurs whether I'm playing loud or soft
      Guitar Type:  Hoehrner "ST Special" - .2 guessed it on the nose
                     - it is a Fender Strat clone
      Equalisation:  I'm not sure what you are referring to
                     here..base/treble setting?, band setting?
      distortion: none
    
    RE: .2
    
      Am I correct in assuming that if I use the selector switch, I
      will be able to find the humming pickup, and that would be the
      one to replace?
    
    Dave

    
    Ahhh....if your problem is *humming* that is quite different than
    feedback, which is squealing noises.   Humming is indeed a common
    property of single coil pickups.
    
    If what you are experiencing is that the guitar hums and buzzes
    when you are not touching any metal on it (like the strings) welcome
    to the club!!!!  A high impedance passive circuit like an electric
    guitar is a natural antenna and picks up hum and noise from everywhere. 
    
    There are many things you can do to reduce the noise, including
    shielding the control and pickup cavities with foil or conductive
    paint, replacing your pickups with humbucking types, etc.  If you
    feel comfortable removing the pickguard and poking around inside,
    you can shield a Strat for under $20.  Changing pickups is of course
    more expensive and also will change the sound of your guitar (maybe
    that's a plus?).   

    .6 is right, there isn't much you can do to eliminate the hum
    completely with single coils. 
    
    Feedback refers to a squeeling sound which builds up volume
    and gets louder and more offensive until you scramble for the
    volume/eq knob and turn it down. This is the same as the squeel
    you get from a microphone when it is turned up too loud or placed
    directly in front of a speaker. The tone pot on the guitar will
    have a greater effect on feedback than the eq on your amp (if
    the feedback is due to a microphonic problem). As I stated in .2
    this is generally due to a loose winding or pole inside the pickup.
    If this is the case, chances are only one pickup is causing it.
    The five-way selector switch on a Strat works as such:
    
    	position 1 (switch pointed towards the strings) Neck pickup on
    	position 2 Neck pickup and middle pickup are both on (in parallel)
    	Position 3 middle pickup on
    	position 4 middle pickup and bridge pickup on (in parallel)
        position 5 bridge pickup on
    
    	If the neck pickup is microphonic, it will squeel in positions
    1 & 2.
    
    	If the middle pickup is microphonic, it will squeel in positions
    2, 3, & 4.
    
    	If the bridge pickup is microphonic, it will squeel in positions
    4 & 5.
    	
   	Not sure if your guitar squeels or just hums. Humming is normal
    with single coils, but no guitar should feedback unless there is
    a defective pickup.
    
    later
    
    Mark
     	                     
                                                  
    

    AHHHHHHH...I see said the blind man to the deaf man....
    
    The noise is definately a hum, not the sqeal one hears from a 
    microphone.   The hum does go away when I touch the strings, leading
    me to believe that my pickups are picking up a signal from
    somewhere.  From what I can tell, I need to get the guitar
    shielded, OR replace the pickup.  Is it difficult to shield
    the guitar?  What kind of materials do I need to do this?

    In my experience, sheilding helps, sometimes, *IF* it's done right...
    Personally, I've never noticed a difference between the two
    methods (sheilded/unsheilded) and I've owned alot of strats and
    teles over the years...  but 'they' say it _can_ make a difference..
    
    
    Humming is what I refer as "Single Coil Blues in 60 cycles or more"
    
    You can never-ever defeat it.  You can lesson it, and maybe that
    is not lessening it to a degree that you can hear, hence the effort
    becomes ineffective.
    
    One thing is for sure, the stock pickups in the guitar you mentioned
    are probably not going to get any less buzz from sheilding.  You
    could replace them, but then you just may wind up in the situation
    that you have more invested in pickups then in your guitar.  (some
    Seymore Duncan single coils run up into 80 bucks...  You'll need
    three....  the math is real easy to follow yes ?)
    
    You can try all kinds of things, but the best solution that allows
    a cure for the humming w/out touching [modifying] the guitar, is to
    pick up a Noisegate/Line-driver type of device.  The noise gate will 
    surpress 'noise' to the degree that you have chosen with a control pot.
    (this control pot is generally referred to as Threshold)  Some rack
    mount compressors have built in gates... you can alos buy them in
    Stomp Box form for about $89-$100... brand new..  (check mail order
    for the better prices.)
    
    Since the noise on single coil guitars are most evident when you
    are not touching the strings, this could be your best bet to cure
    your problem.  The noise gate has literaly no effect on the signal
    or sound (if you will) of the signal.
    
    (That comment is subject to quality of the noise gate) 
    
    But it will effectivley 'cancel' any noise that you tell the noise
    gate to cancel via the threshold of what you consider noise, and not music.
    (e.g. buzzing...)  This is a process of trial and error till you
    find the best setting, but once you find it, mark the setting and
    leave it there, always..
    
    You could effectivly cancle all sound, (threshold up all the way,
    bang on the strings, nothing happens cuz you've told the noise gate
    to surpress 100% of the signal) or just the buzzing (threshold up till 
    the buzzing stops, but as soon as you strike a string, you're there)  
    
    All depends on how you set the threshold of the gate.  again, a
    little tricky at first, but very effective once you know what you're
    doing with it..
    
    Check want adds and such..  You may find one cheap...
    
    Cheaper than replacing pickups....    
    

    One more thought...
    
    It may have sounded like I painted a bleak picture with the cost
    of replacing pickups, but consider this.. (after reading a few
    comments that pickups can be had for under 30 bucks a peice, I
    figured I had better add some quality to my last note..)
    
    and while this is quite true, the point I'm going to try and make
    is that If you buy pickups in the 20 to 25 dollar range, to me, it's 
    very conceiveable that you've just trown the money away.  You may
    very well wind up with the same problem you have now, or worse
    yet, the buzz still exists, but now the pickups you just bought
    for $15.00 are also microphonic.  (GASP!)  also, replacing pickups
    is a kid gloves job.  Knick just one of those iddy-biddy copper
    windings, and that pickup is mushed !  Ask me about it,,,  I sent
    a 75 dollar Seymore Duncan to an early grave last summer... Luckily
    it's repairable, but I had to send back to california and have Seymore
    Duncan do it..  Nice guys out there by the way..  Real helpfull,
    courteous...)
    
    So, before I get beat up for my pricing opinions on new pickups,
    understand that it was based on an opinion that you'd be purchasing
    'better' pickups, not new pickups of equal design/quality that exisit
    in the guitar today, and could very well have the same if not more,  
    problems.  (I'd guess that stock pickups in Honer, Kent, etc...
    guitars are problem worth somewhere arond 20 to 25 bucks...)
    
    To me, there is "Nothing" worse than microphonic feedback from a
    guitar ! (well maybe there's worse things, but thats up in the top
    5 to me...)
                                                           
    Just keep in mind that buzzing is inherant of single coild pickups.
    The better the pickup, perhaps, the less buzz...
    
    I still say to defeat the problem, use a different tool, and
    in this case that would be the noise gate.
                

    If you buy the EMG select's from Stewart McDonald's for $17.50 each
    chances are real good that they won't be microphonic, none of mine
    were. However, I admit that I did replace them eventually with Semour
    Duncan hot stacks ($65 each) as I like the sound and output of the
    duncan's better.
    
    I must be lucky with pickups or something, I have never had a pickup
    die on me, and at least two noters here have had duncan's die, one
    that I know iof had and EMG active die....I did manage to kill a
    pickup once though...
             
    dbii

    
    
    	DBII, yup, I agree the EMG selects are quiet as little mice!
     In, my case humming wasn't just pickups!!  1. I also had a broken
    string ground, that was allowing my antennas (oops, strings <grin>)
    to pick up the neighbor's skill saw.  2. Needed to include solder
    lugs to run the mechanical part of my new switches to ground.
    Electrical grounds and RF grounds are two different things. When
    we eliminate hum and other nasty noises we're usually creating both
    type of ground....  It's fun to hook up a switch in series with
    certain grounds and actually hear the difference that a given grounding
    effect has...
    
    
    Steve

    Strange, I bought a box full of pickups with a single broken wire on
    each of the windings (on one of the coils). Paid $8.00 for it. It had
    13 or 14 pickups in it (I bought it from a store that does repairs).
    The fellow that I bought it from was happy to get rid of them. With
    a bit of work, I found the single broken wire on all of them. They all
    wnet back into service (I used them for repairs, trades and any guitars
    that I built). If you are ambitious, you might be able to walk into
    a similar situation and resolve it in the same way. I ended up with
    GIBSON, FENDER, MITY-MITE, DI-MARZO and Japanese Humbuckers (mostly
    the better known brands).

    If you decide to do this, take the tape off of the pickup (it covers
    the approx 4000 turns of hair thickness wire) & look for the broken
    one. It often is only 3 to 10 turns from the beginning, so you don't
    really loose much sensitivity from these 'missing' turns. In the case
    of a humbucking pickup, you have to carefully remove the coil that
    shows open (check with a VOM, if it is open, you'll know it - unsolder
    both wires carefully), then take the tape off and start looking for the
    broken wire. If it's not easily found, set the coil aside & see if you
    have another pickup like it lying around that has a similar problem.
    You might have 2 coils that are fine & 2 that are not repairable. Use
    the 2 coils that are good to make one good pickup. You need to be
    careful how your solder the wires back in on the humbucker, remember
    that coils are would opposite of each other such that you get a
    differential voltage (that cancels hum & other noises). I ended up
    (over time) with a box full of bad single coils, but always seem to
    be able to save most of my 'near free' pickups.

							    Jens
    
    
    

    	Just another thought on the subject of hum/buzz.....
    
    	Dimmer switches (in the 1/2 position) or florescent lights can
    	also add significantly to the hum/buzz. If you are using these
    	siwtches/lights and the hum is more noticable at night then
    	these are definitely contributing... or like wise if your gigging
    	and the hum is more noticable at one venue rather than another
   	then the chances are they're using dimmers.....
    
    	-.. just a thought  but worth checking out initially...
    
    	Ray