Results 1 to 25 of 25
Like Tree14Likes
  • 3 Post By salvarsan
  • 1 Post By 12xu
  • 1 Post By rjb
  • 1 Post By copperheadroads
  • 1 Post By charrich56
  • 1 Post By big_teee
  • 1 Post By salvarsan
  • 2 Post By charrich56
  • 3 Post By Zhangliqun

Thread: Firebird PU small metal top plate - necessary?

  1. #1
    Senior Member
    Join Date
    Nov 2009
    Location
    Dallas-Fort Worth, TX, USA
    Posts
    151

    Firebird PU small metal top plate - necessary?

    Could someone comment on the Firebird pickup, whether the small sheet metal piece which is installed on the treble side on top of the two magnets, is either necessary or desirable, if you don't want to necessarily duplicate the Firebird PU sound?

    Does it make the string outputs more balanced bass to treble, or anything along those lines?

    Thanks in advance for replies/comments.

    -Charlie

  2. #2
    rjb
    rjb is offline
    Old Timer
    Join Date
    Feb 2010
    Location
    Somewhere near Bawlmer, Merlin
    Posts
    2,167
    My guess is that the ferrous metal sheet reduces the magnetic field reaching the treble strings.
    The obvious answer is "try it".

    -rb

  3. #3
    Senior Member
    Join Date
    Nov 2009
    Location
    Dallas-Fort Worth, TX, USA
    Posts
    151
    Yep, it would shunt some of the field which would magnetize what looks like the G and B strings. But knowing what Gibson's rationale for doing it in the first place, would save me some experimentation time I'd like to devote to some other things.

  4. #4
    Senior Member salvarsan's Avatar
    Join Date
    Jan 2008
    Location
    The pines country.
    Posts
    1,089
    Quote Originally Posted by charrich56 View Post
    Could someone comment on the Firebird pickup, whether the small sheet metal piece which is installed on the treble side on top of the two magnets, is either necessary or desirable, if you don't want to necessarily duplicate the Firebird PU sound?
    Yes, it's a magnetic field soak to decrease the B,G string contributions.
    Lacking adjustable screws, it's an economical pickup tweak.
    The StewMac picture helps explain things.
    firebird_mini_humbucker_pickup_kit.jpg
    charrich56, big_teee and ReWind like this.
    The lofted fewmet doth soon hew close to the whirling blades.

  5. #5
    Member
    Join Date
    Nov 2014
    Posts
    61
    I've had good results without using the plate.
    charrich56 likes this.

  6. #6
    rjb
    rjb is offline
    Old Timer
    Join Date
    Feb 2010
    Location
    Somewhere near Bawlmer, Merlin
    Posts
    2,167
    Quote Originally Posted by 12xu View Post
    I've had good results without using the plate.
    [wild speculation]
    Maybe because you use an electrically well-balanced string set?
    I wouldn't doubt the "old-school" guys at Gibson tested the pickup with "old-school" strings....
    [/wild speculation]

    -rb
    charrich56 likes this.

  7. #7
    Member
    Join Date
    Nov 2014
    Posts
    61
    Quote Originally Posted by rjb View Post
    [wild speculation]
    Maybe because you use an electrically well-balanced string set?
    I wouldn't doubt the "old-school" guys at Gibson tested the pickup with "old-school" strings....
    [/wild speculation]

    -rb
    I've always heard that was the reason they did it.

    Not needed with modern strings.

  8. #8
    Woodgrinder/Pickupwinder copperheadroads's Avatar
    Join Date
    Jun 2009
    Location
    Iceburg Alley ,Newfoundland,CAN
    Posts
    2,021
    I don't find a unbalanced strings without the small B plate so I don't use it .
    ReWind likes this.
    "UP here in the Canada we shoot things we don't understand"

  9. #9
    Senior Member
    Join Date
    Nov 2009
    Location
    Dallas-Fort Worth, TX, USA
    Posts
    151
    Thanks, guys, I appreciate all your answers.

    I've thought for a long time that the mini-humbucker/Firebird PU was treated like the red-headed stepchild of the pickup world, but maybe a good modern design could offer some great tones and some advantages for fit (fits P-90 cavity easily with the adapter, and you can put 3 of them on a Strat pickguard.)
    salvarsan likes this.

  10. #10
    ToneOholic! big_teee's Avatar
    Join Date
    Jun 2010
    Location
    Mid-South USA
    Posts
    9,785
    I made a firebird hybrid I liked a lot, a couple of years back.
    Used the standard baseplate, bobbins & firebird cover.
    Inside I used a standard humbucker A8 Bar mag on the bottom.
    Used 2 custom cut slug bars in the bobbins.
    I cut the slug bars a little wider so they barely stuck through the top of the bobbins, allowing to sit near, or against the cover.
    An advantage with the slugs, you can use any standard Humbucker magnet underneath.
    A2-A8, C5, or C8.
    Worth a try, if you're trying to come up with something different.
    I liked it! Can be tuned warm or bright, depending on bar magnet.
    T
    charrich56 likes this.
    Technicians Run the World, but Bankers, Lawyers, and Accountants, Take All The Credit!
    Keep Rockin! B_T
    Terry

  11. #11
    Senior Member salvarsan's Avatar
    Join Date
    Jan 2008
    Location
    The pines country.
    Posts
    1,089
    Quote Originally Posted by rjb View Post
    I wouldn't doubt the "old-school" guys at Gibson tested the pickup with "old-school" strings....
    "Old School" could mean a wound G back when the G-string really meant something.

    Makes you wonder about how much the G-string actually contributed to the sound of honky-tonk Rock&Roll.
    It suggests that limiting the G-string contribution was a priggish cultural affectation, an insidious Bowdlerization of guitar pickup sonority.

    G-string issues have a long history.

    [trivial pun alert]

    Going for Baroque, there is a record of J.S.Bach
    contributing a long clipping of his hair to make a multifilar G-string for the violin,
    this being the earliest recorded instance of...

    [loathsome pun alert!]

    ...Bach's hair in a G-string.
    David Schwab likes this.
    The lofted fewmet doth soon hew close to the whirling blades.

  12. #12
    Senior Member
    Join Date
    Nov 2009
    Location
    Dallas-Fort Worth, TX, USA
    Posts
    151
    Quote Originally Posted by salvarsan View Post
    "Old School" could mean a wound G back when the G-string really meant something.

    ...

    [loathsome pun alert!]

    ...Bach's hair in a G-string.
    Anybody who would get that reference would also probably know what Salvarsan is, Salvarsan.

    But you are probably right about the wound G-string. That means full speed ahead on leaving the darn piece of metal out.

    Big_teee has an interesting idea on a hybrid. But I'm a bit cautious about how high the inductance would go with both rails and an Alnico mag. I'd like to stay at or a little under 4.0 Henries series coil, 1 Henry parallel coil, for my specially challenged electronics. I might be able to work with Sonny Walton, who lives close to me (and has a CNC winder,) to experiment a bit.

    PRS has been putting out some pickups in their guitars which have an "in-between" string aperture, and I've been hearing some good opinions on some of the minihum and Firebird -inspired custom PU's out there.


    -Charlie
    Last edited by charrich56; 06-03-2017 at 11:28 PM.

  13. #13
    Member
    Join Date
    Feb 2010
    Posts
    65
    This is the answer of Peter Schultz from Stewmac

    Thank you for contacting us. The small steel plate across the top of a Firebird Mini Humbucker helps to focus the vibrations of the "B" string. This causes the "B" string to have a slightly higher output relative to the other strings.

    Using one of these Firebird Mini Humbuckers, you will notice that the "B" string sounds more compared to the other strings. This small steel plate is part of the vintage technical specifications that contribute to the vintage sound of these pickups.

  14. #14
    rjb
    rjb is offline
    Old Timer
    Join Date
    Feb 2010
    Location
    Somewhere near Bawlmer, Merlin
    Posts
    2,167
    Quote Originally Posted by marcfrom View Post
    The small steel plate across the top of a Firebird Mini Humbucker helps to focus the vibrations of the "B" string. This causes the "B" string to have a slightly higher output relative to the other strings.
    Hunh.
    Historically, pickups always had a problem with the "B" string having higher output- because the plain steel "B" string was thicker than the core of the wound "G" string. That's why Gibson started notching "Charlie Christian" polepieces below the "B" string in 1938.

    https://en.wikipedia.org/wiki/Gibson...tian_pickup.22

    -rb

  15. #15
    Member
    Join Date
    Feb 2010
    Posts
    65
    Quote Originally Posted by rjb View Post
    Hunh.
    Historically, pickups always had a problem with the "B" string having higher output- because the plain steel "B" string was thicker than the core of the wound "G" string. That's why Gibson started notching "Charlie Christian" polepieces below the "B" string in 1938.

    https://en.wikipedia.org/wiki/Gibson...tian_pickup.22<

    -rb
    yes it's true even on the Strat Pickups the B rod is more away from the string.

    But does the ferrous plate do not increase the magnetics field around itself as a Tele bridge pickup?

  16. #16
    rjb
    rjb is offline
    Old Timer
    Join Date
    Feb 2010
    Location
    Somewhere near Bawlmer, Merlin
    Posts
    2,167
    Quote Originally Posted by marcfrom View Post
    But does the ferrous plate do not increase the magnetics field around itself as a Tele bridge pickup?
    I dunno. Post #2 is still my best guess.

    -rb

  17. #17
    Senior Member
    Join Date
    Nov 2009
    Location
    Dallas-Fort Worth, TX, USA
    Posts
    151
    Quote Originally Posted by rjb View Post
    I dunno. Post #2 is still my best guess.

    -rb
    The response from the Stew-Mac guy sounds like the opposite of what one would expect by partially "shunting" the magnetic field under the B string with the piece of metal, and reducing output. I do appreciate the asking, though.

    BTW just as an aside, the GFS Gold Foil P-90 humbuckers actually look like a classic Firebird HB design (minus the little metal piece in question) when one peeks under the gold foil on top. Also, the "polepiece" screws are probably stainless and definitely non-magnetic, as verified by my Spin Doctor gaussmeter, therefore they are there completely for looks. The polepieces aren't necessarily bad, I'm just commenting on what they are. I'm going to throw my set into an Epiphone I have handy, with a variable rez tone control, and see if they can make good sounds.

  18. #18
    Member
    Join Date
    Feb 2010
    Posts
    65
    Quote Originally Posted by rjb View Post
    I dunno. Post #2 is still my best guess.

    -rb
    Especially the "Try it".

    Somebody else has an opinion ?

  19. #19
    rjb
    rjb is offline
    Old Timer
    Join Date
    Feb 2010
    Location
    Somewhere near Bawlmer, Merlin
    Posts
    2,167
    Quote Originally Posted by marcfrom View Post
    Somebody else has an opinion ?
    To put it undiplomatically, my opinion is that the Stew-Mac guy is all wet.
    So far, there seems to be a consensus about the purpose of the piece of metal, if not about the Stew-Mac guy.

    -rb
    Last edited by rjb; 06-23-2017 at 04:57 AM.

  20. #20
    rjb
    rjb is offline
    Old Timer
    Join Date
    Feb 2010
    Location
    Somewhere near Bawlmer, Merlin
    Posts
    2,167
    Quote Originally Posted by charrich56 View Post
    BTW just as an aside, the GFS Gold Foil P-90 humbuckers actually look like a classic Firebird HB design (minus the little metal piece in question) when one peeks under the gold foil on top....
    As an aside from the aside, the GFS Gold Foil Alnico V (non P-90) humbuckers are built like "regular" humbuckers, with bobbins of the same dimensions. DCRs of 5.4K (neck) and 6.0K (bridge) of 43AWG puts them in the ballpark of 3000 turns/coil. I know because GFS is phasing out the 4-conductor fixed solder leads and replacing them with 3-conductor detachable leads; I wanted the option of wiring the coils in parallel, so....

    Quote Originally Posted by charrich56 View Post
    I'm going to throw my set into an Epiphone I have handy, with a variable rez tone control, and see if they can make good sounds.
    By "variable rez tone control", do you mean a rotary switch with a bunch of capacitors?

    -rb

  21. #21
    Woodgrinder/Pickupwinder copperheadroads's Avatar
    Join Date
    Jun 2009
    Location
    Iceburg Alley ,Newfoundland,CAN
    Posts
    2,021
    Quote Originally Posted by charrich56 View Post
    The response from the Stew-Mac guy sounds like the opposite of what one would expect
    I've had conversations with them ....Trust me they are not winders .
    "UP here in the Canada we shoot things we don't understand"

  22. #22
    rjb
    rjb is offline
    Old Timer
    Join Date
    Feb 2010
    Location
    Somewhere near Bawlmer, Merlin
    Posts
    2,167
    It seems we're approaching a consensus about the Stew-Mac guy...

  23. #23
    Senior Member
    Join Date
    Nov 2009
    Location
    Dallas-Fort Worth, TX, USA
    Posts
    151
    Quote Originally Posted by rjb View Post

    As an aside from the aside, the GFS Gold Foil Alnico V (non P-90) humbuckers are built like "regular" humbuckers, with bobbins of the same dimensions. DCRs of 5.4K (neck) and 6.0K (bridge) of 43AWG puts them in the ballpark of 3000 turns/coil. I know because GFS is phasing out the 4-conductor fixed solder leads and replacing them with 3-conductor detachable leads; I wanted the option of wiring the coils in parallel, so....


    By "variable rez tone control", do you mean a rotary switch with a bunch of capacitors?

    -rb
    Even better. I use a buffer to bootstrap a capacitor through a pot, and can continuously vary the load capacitance, therefore the pickup resonant frequency, over more than 1 1/2 octaves. Beats the pants off a regular tone control. The buffer allows independent setting of pickup load resistance to control Q. It works very nicely. Here's the thread on it: Variable Resonance Pickups - Fun with Buffers

    The "variable rez tone control" really stands for "variable resonant frequency tone control." I don't have a cuter name for it yet.

    I designed an open-sourced 2-JFET buffer that works well with this approach. It's close to the end of the thread. There will be a commercial SMT version of this buffer very soon.

    -Charlie
    Last edited by charrich56; 06-23-2017 at 06:22 AM.
    salvarsan and rjb like this.

  24. #24
    Senior Member
    Join Date
    May 2006
    Posts
    785
    Regarding the original question: FWIW, I've made them both ways and I can't hear a difference so I stopped bothering with it.

  25. #25
    Senior Member
    Join Date
    Sep 2011
    Location
    Minneapolis
    Posts
    274
    Quote Originally Posted by marcfrom View Post
    This is the answer of Peter Schultz from Stewmac

    Thank you for contacting us. The small steel plate across the top of a Firebird Mini Humbucker helps to focus the vibrations of the "B" string. This causes the "B" string to have a slightly higher output relative to the other strings.

    Using one of these Firebird Mini Humbuckers, you will notice that the "B" string sounds more compared to the other strings. This small steel plate is part of the vintage technical specifications that contribute to the vintage sound of these pickups.
    Ummmm...

    Of all of them I have made, the only difference has been that the field is shunted on the B & G strings. I now make them without.

    I just did a bridge FB for a guy and he wanted it "pure vintage" so I cut and applied the little plate. He called back right after picking it up complaining there he couldn't here the B & G string as well.

Thread Information

Users Browsing this Thread

There are currently 1 users browsing this thread. (0 members and 1 guests)

Similar Threads

  1. Modern Firebird PU.
    By 12xu in forum Pickup Makers
    Replies: 26
    Last Post: 02-28-2015, 02:08 PM
  2. Firebird pickups W/ or W/O the ferrous plate
    By copperheadroads in forum Pickup Makers
    Replies: 7
    Last Post: 10-08-2012, 02:10 AM
  3. Material for top and bottom PU plates
    By safas in forum Pickup Makers
    Replies: 4
    Last Post: 12-25-2008, 04:54 PM
  4. top plate for ac30
    By chris025 in forum Cabinetry
    Replies: 4
    Last Post: 10-31-2008, 08:38 AM
  5. firebird PU covers
    By rocket in forum Pickup Makers
    Replies: 5
    Last Post: 07-26-2008, 09:05 PM

Bookmarks

Posting Permissions

  • You may not post new threads
  • You may not post replies
  • You may not post attachments
  • You may not edit your posts
  •