Conference napalm::guitar

    The "back half" has nothing to do with the intonation. In fact,
    I doubt if it actually has adjustable height, as you suggest. I
    know Gibson tailpieces have screw-down attachments (I have an ES-345),
    but these are meant to be tightened down all the way. If you backed
    them off to raise the tailpiece you be risking having the whole
    thing rip off the body.
    
    What you want to do to set the intonation is adjust the individual
    support bridges for each string in the "front half". This is very
    simple to do, since each one has a separate screw in the side of
    the bridge (I assume). The procedure may have been described in
    another note, but basically you check the harmonic at the 12th
    fret, and compare it to the fretted note at the same fret. If the
    fretted note is higher, adjust the screw so that the bridge piece
    moves farther away from the neck. If the fretted note is lower,
    adjust the screw so that the bridge piece moves closer to the neck.
    Keep doing this until the two notes sound at the same pitch. Then
    repeat the process for each of the other strings.
    
    I'm making assumptions about your ES-355 bridge. If what I said
    doesn't make sense to you, you'll have to provide more details on
    the design.

    

    
    The tailpiece on my 355 is suspended--that is, it is it does not
    set flush to the body. It is raised a little of the body. This is
    the type of tail piece that has fine tuning adjustment knobs that
    you can turn by hand to "fine tune" each string. Are you familiar
    with this type of tailpiece? It is elevated off the body, and the
    bridge is elevated even higher off the body. 
    
    My original intent was to raise the action by raising the bridge,
    then adjust the intonation. I believe your right about intonation
    adjustment on this guitar. 
    
    My do you know about raising the action? Is there anything I should
    know about it other than raise the bridge by turning the knurled
    knobs counter clockwise?  
    
    Rob

    From your description, you have a "TP6" fine tune tailpiece.
    The height of this taipiece CAN be adjusted, but it is not intended
    for intonation (as has been mentioned). It's meant to be a "string
    feel" adjustment, ie, the closer you adjust the tailpiece to the body, 
    the stiffer the string action. 
    
    What I usually do is screw the tailpiece down all the way, then
    back it off about a 1/4" to 1/2". After this I adjust the bridge
    for height and intonation.

    Hope this helps,     
    Dan

    re: .2
    
    It sounds like you have exactly the same tailpiece as I have on
    my 345, and everything I said before about adjusting the intonation
    would hold. As far as adjusting the hieght of the bridge, yes, you
    just turn the knobs under the "front half" to raise or lower it.
    Then check the intonation as I described in .1. If you want to ask
    about changing the action we would have to know why you are changing
    it (i.e., up or down, what's wrong with it, what do you expect to
    accomplish by changing it), and whether you have already evaluated
    other factors such as the straightness of the neck, condition of
    the frets, string guage, etc.
    
    re: .3
    
    What do you mean by "string action"? It sounds like you expect
    adjusting the height of the "bottom half" of the tailpiece to affect
    how stiff the strings feel. Personally, I can't see that the height
    has anything at all to do with the sound, action, or feel, other
    than that you might bump your right hand against it if it was set
    too high.
    
    I'll check my 345 again to make certain, but I'm pretty sure those
    screws that hold the "bottom half" onto the body are not meant to
    be adjusted. On my guitar they are designed so that the tailpiece
    can be slipped out without unscrewing them. I repeat that backing
    them off will weaken the contact of the tailpiece with the body,
    and could result in the thing ripping off. Like I said, I'll check
    it again, but unless someone has a definitive answer on this I wouldn't
    back them off.
    
    - Ram

    Re .3,.4
    
    Dan's right. The 'front half', by the way, is called the bridge,
    as in 'tune-o-matic bridge'. The back half is called the tailpiece.
    The stiffer the angle of the strings over the bridge (and nut too,
    for that matter) the stiffer the feel of the strings, and the more
    sustain the instrument has. I still wonder what the relationship
    is - I think the tension is a function of (1+sin(angle of string
    break)). I can certainly tell a difference when I raise or lower
    the tailpiece on my Les Paul. There are other factors which
    significantly affect how a guitar feels - scale length, the presence
    or lack of a trem. system, string and nut hight, neck relief, etc.
    
    -Dave
    up pretty far on my Les Paul.

    I've used them to adjust the action on my Les Paul (copy) and on
    a friends for several years with no problems.  They definately make
    a difference in the relative stiffness of the action.  The posts
    have about 1.5 inches of thread so I can't believe that raising
    them 1/4 of an inch would pose any structural problems for the guitar
    body.
    
    BTW, when I have those tailpiece posts screwed down all the way
    the action is SOOOOoooooo stiff, it's almost unplayable.
    
    Greg
        

    
    Gee, and I just wanted to know how to set the intonation. (I love
    this notes file!) Well, I've set the intonation and the guitar sounds
    in good tune over the entire finger board. After all this talk of
    tail pieces, I didn't touch the tail peice on my 355. I like the
    way the guitar feels. But it's interesting to know how many different
    ways you can adjust the guitar. 
    
    Thanks,
    
    Rob

    re: .6 and .7
    
    Sounds like bs to me, but I'm definitely going to go home tonight and
    try adjusting the height of the tailpiece to set if it actually has any
    effect on the string feel. It just seems to me that the string is
    hanging between the nut and the bridge, and it doesn't make any sense
    that the angle between the bridge and the tailpiece would have anything
    to do with the feel. 
    
    Are there any scientists among us who understand the properties
    of wire under tension?

    - Ram

    I agree. I don't understand what the angle would have to do with
    the feel. Except maybe the angle has some relationship to the firmness
    of the tailpiece (rigidity), which I know would make a difference
    in the feel (like playing a whammy equiped guit).
    
    pcv
    

This is according to my "Gibson Les Paul Owner's Manual"
    
"Adjustable, Stop Bar Tailpiece"
    
  The stop bar tailpiece may be adjusted up or  down thereby creating
  different degrees of downward pressure across the bridge.  Lowering
  the tailpiece will result in a stiffer action while raising it will
  create a more flexible feel to the strings. Note: Excessive lowering
  of the stop bar tailpiece may cause premature breakage of the strings.
  Caution is encouraged.
    
"TP-6 Fine Tuning Tailpiece"
    
  The individual screws are fine tuning adjustments for each string.
  Turning the screw clockwise raises the pitch of the string; turning
  it counter-clockwise lowers the pitch. The TP-6 also functions as
  a normal stop bar tailpiece; that is, adjustable up and down so as
  to decrease or increase "down pressure" across the bridge saddle.
    
  The tailpiece has been set to a median level at the factory. Lowering
  the tailpiece will increase response and sustain and yield a somewhat
  firmer  action. Raising will give the opposite of these characteristics.
  CAUTION: Lowering the tailpiece excessively may cause premature string
  breakage.
    
    	

    I guess I'll have to accept their word for it. But I'm certainly
    going to experiment to see what happens.
    
    - Ram

    I tried this on my old les paul custom...it's true but the differences
    are not that profound...
    
    dbII

    I *knew* this worked, although I agree that it doesn't seem like
    it should make a difference.  I think the degree of difference is
    relative to the gauge of the strings you're using.
    
    Greg

    I'm no expert, but I did have a couple of courses on vibrations
    and wave motion, and I've done some experimenting.  The guitar is
    a very difficult machine to model mathematically, so its easy to
    oversimplify when you talk about it.  
    
    This is an interesting phenomenon and I think there are several
    components to it.  If you have a very small breaking angle, you
    get a weak, dirty sound with little sustain (relatively).  This
    is because some of the vibrational energy is transferred behind
    the bridge, into the tailpiece.  With a steep breaking angle, the
    theoretical end point of the vibrating string is 'nailed down' better,
    so less energy is lost over the bridge.
    
    A string with a small angle will tend to feel a little softer because
    it actually slides laterally and stretches slightly over the bridge.
    This is destructive to the sound because it means that the theoretical
    quiescent tension of the string and its vibrating length are not
    constant.  
    
    Another component is the downward force applied to the bridge. 
    This increases with the breaking angle, and contributes to overall
    stiffness in the soundboard.  Within limits, a stiffer soundboard
    tends to make a cleaner sound and a slightly harder feel, but I
    think the difference in feel would be pretty subtle.
    
    The tension in the string, at rest, is independent of the breaking
    angle.  If the tension changed, the tuning would also change.  When
    the string is plucked, the tension varies very slightly with the
    vibrations.  If the breaking angle is too small, the tension will
    tend to be slightly less, while the string is stretched, than with
    a steeper angle.

    Bob    
    
    

    The title of the last reply was just a typo.  Don't puzzle over
    it.

    re:.14
    
    Yeah, now that makes sense...
    
    Thank you, even though I didn't pose the original question, I was
    very puzzled...
    
    pcv
    

    re: .14
    
    Yes, thanks also. That makes some sense to me. I actually went home
    over the weekend and raised the tailpiece on my 345, confirming
    that it really is designed to be adjustable. What I had said earlier
    about it being screwed down all the way was incorrect, because the
    screws enter sockets that are embedded in the body, and are obviously
    intended to be raised and lowered.
    
    As far as the effect of raising it goes, I couldn't feel any
    significant difference in the action. I could believe what was said
    about the sound getting dirtier and having less sustain, because with
    less downward force across the bridge saddle it is obviously easier for
    the strings to rattle. It also seems to me that raising it still
    introduces some weakness, since you are pulling the tailpiece sideways
    against the screw posts when it is raised up. Furthermore, guitar
    makers traditionally go to great pains to fasten bridges securely to
    the body to improve tone and sustain, so it still seems
    counter-productive to raise the tailpiece. 

    But each to his/her own.
    
    - Ram

    re: .14
    
    Great analysis, Bob!  Thanks!
    
    glh
    

    
    One guess is that the frets weren't properly spaced by the factory,
    which doesn't seem to be as uncommon as you might think.  There is
    be some sort of scale that the shop can lay against the neck to
    determine if the frets are spaced correctly.
    
    Kevin
    
    

    The nut could very well be to high causing additonal tention which in
    turn will raise the pitch. The further away from the nut, the closer
    the note will be to the correct pitch. I've worked on these problems,
    and fixed by shaving the nut to a hight just before fret buzz, then
    adjust action, intonation and done.
    
    If new, there's no excuse...bring it back and have it fixed or
    raplaced!
    
    Dave'
    

    LV.... when you bought the guitar,was it out of the box or did they
    set it up for you? I wonder if high fret's or improperly leveled or
    crowned frets could be the problem?
    
    							Rick
    

    it could be that the string is sitting in the nut slot but the
    'break point' for the string is not exactly flush with the front
    of the nut (I hope you can picture this). It wouldn't take much
    to give you an intonation problem.
    
    - Dave

    Usually if the nut is high enough to present problems with the
    intonation, then the action is really poor as a result of it too.  The
    typical test for nut height is to fret the guitar at the third fret (so
    it's pressed down on the second fret behind your finger) and check the
    gap between the first fret and the string.  It should be very small,
    like .015 or so.  If you have a big gap, then the nut height is
    probably the problem.

    I didn't read real carefully, does this problem affect more then one
    string?  If it's all of them, it's probably not the nut height, but
    more like the nut placement (or the string contact point on the nut, as
    Dave suggested).  The fret slots on all mass produced guitar (and most
    customs as well, are machine cut from precise templates, it's
    practically impossible for them to be improperly spaced.  However, it
    would seem to me that the entire fretboard could be improperly
    positioned on the neck, which could cause such a problem.  Or the nut
    or bridge could be in the wrong place.

    Greg