Piezo in an Electromatic Center Block Jr...

Discussion in 'The Pickup Place' started by GlenP, May 24, 2021.

  1. GlenP

    GlenP Country Gent

    Jul 23, 2019
    WA
    This demo gives me hope that it is crazy enough, it just might work! The same LR Baggs piezo system in a similar size, but light weight chambered solid guitar

     
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  2. GlenP

    GlenP Country Gent

    Jul 23, 2019
    WA
    Another piezo equipped guitar with a Bigsby, the Dean Colt Piezo. Semi hollow with Florentine single cut. This is totally passive, no on board preamp, or batttery, but there are several options for pedal type preamps/DI boxes you can use for the piezo out, but seems like I have no reason to worry about any noise from the Bigsby sliding strings over the piezo saddles. On sale right now, not too shabby!

    https://www.musiciansfriend.com/dean-colt-bigsby-with-piezo-semi-hollowbody-electric-guitar
     
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  3. GlenP

    GlenP Country Gent

    Jul 23, 2019
    WA
    In doing some research I found a post on Strat-Talk from a few years ago where someone installed this LR Baggs T-Bridge in a Gretsch 5120 with a stereo jack for the passive mag/pie output, and then installed the Control-X in a pedal box with the battery and control board/pot, with stereo in/out for the mag/pie and blend functions. The external box could also be worn as a strap/belt pack, very clever idea.

    Since that Gretsch has the wooden bridge base, he did not drill through that and into the guitar, he just notched the pickup ring and ran the T-Bridge piezo wires into the bridge pickup cavity.

    https://www.strat-talk.com/threads/next-build-the-gretsch-electrocoustimatic-5120-deluxe.442781/

    Still waiting on my gold-plated stereo jack to arrive in the mail, and my custom toggle switch plate for the mag/pie selector. I want to make sure I have all parts on hand and do some planning and thinking before I start drilling, you know?
     
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  4. GlenP

    GlenP Country Gent

    Jul 23, 2019
    WA
    60E94FB7-E268-4A59-B871-5FB88A9FF45C.jpeg Making a template for my “pickguard” layout of the electronics...
     
  5. GlenP

    GlenP Country Gent

    Jul 23, 2019
    WA
    Also, this gold switched stereo jack arrived in the mail, I will replace the pre wired chrome jack that came in the kit.

    FEEC5683-09A2-4B7F-81AB-0DFFE58CF040.jpeg
     
  6. LivingMyDream

    LivingMyDream Friend of Fred

    Glen, it's cool to see this taking shape.

    BTW, yesterday, I saw that Schecter has a C-1 E/A (piezo & mag), and I mention it because they gave it controls that give tone and volume control for both the piezo and mag pickups. Also they have a toggle switch for combining the piezo and mag pickups, instead of a blend knob like my PRS has. If I didn't already have the PRS, I would have pulled the trigger. Even so, I like the mag/piezo combo so much that I had to fight the urge to get one. The thing that saved me is that they are now on back order just like the PRS was.

    Here's a pic of how it's set up.

    [​IMG]
     
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  7. GlenP

    GlenP Country Gent

    Jul 23, 2019
    WA
    38BE58EE-F75B-43B8-B6A8-752FC558CB87.jpeg 29EBA728-BAED-48D6-8CB1-63A8ABA0BE16.jpeg
    Thanks for the info. I think the Schecter uses the Fishman and PRS uses the LR Baggs.

    I have been doing my homework about different wiring options, and I don’t really mind drilling new holes in the guitar, but I think I have come up with a couple of good options that will use the existing holes.

    I was glad to see the Dean Colt Piezo because that one has a Bigsby, it seems that the piezo saddles in the TOM bridge work just fine with the Bigsby.

    well, now I am not just involved, I am committed, the T bridge has been installed. The drilling was not too hard, but the fishing of the wires took a little bit of ingenuity. When the bridge is in place you really can’t see the wires underneath unless you get really close. There is plenty of room in the bridge pickup up cavity to run the piezo signal wires into the preamp board. Even though this particular installation will just sum all the six saddles into one, I am marking them to keep track of each string saddle wire, so that a potential future upgrade to a full MIDI system could be done later.

    first I made like a hook in the end of a stiff wire from the bridge cavity side and dropped a loop of dental floss from the top. After I had the floss threaded, I tied a piece of paracord that had the core strings removed. The hollow paracord made like a sheath which I inserted the piezo wires, the tighter you pull on the paracord the tighter it grips the wires, so I was able to route the wires through those two drilled holes turning a pretty sharp corner.
     
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  8. LivingMyDream

    LivingMyDream Friend of Fred

    Sounds like it's coming alone very well, Glen. I sure didn't mean to throw you any curves. I just didn't know whether you had things completely figured out yet. I will quietly await the outcome, and I know you're going to love it.
     
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  9. GlenP

    GlenP Country Gent

    Jul 23, 2019
    WA
    No problem, I appreciate the info. I will need to draw up my own wiring schematic for this one, it will be slightly different than the Fender Strat and Gibson LP diagrams that LR Baggs provides, but they are not that hard to Gretschify once you understand their signal paths.

    Besides the wiring, which will be pretty time consuming, a couple other guitar modifications are on the way: mounting the 1/4” mini toggle in the 1/2” pickup switch hole, and installing a battery box.
     
    Last edited: Jun 7, 2021
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  10. GlenP

    GlenP Country Gent

    Jul 23, 2019
    WA
    I was really happy to get those holes drilled safely into the top and into the bridge cavity. Once I got the paracord threaded, I was home free. If I had been a little smarter, I could have wrapped some paracord in sandpaper, and used that to smooth out that internal acute corner from the vertical hole to the angled hole, to make the path easier to thread the wires through.

    But, threading the individual wires into the hollow paracord first really made it easy to pull them all through at the same time, even around that sharp turn between the two drilled holes. I got the idea to use the paracord from those woven finger trap toys that squeeze tighter when you pull them apart, that's exactly how the paracord sheath worked with the piezo wires inside.

    Screen Shot 2021-06-07 at 1.53.44 PM.png
     
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  11. GlenP

    GlenP Country Gent

    Jul 23, 2019
    WA
    Also, before installing the piezo bridge, I tried to eyeball as best as I could the saddle positions measured from the original bridge. Not sure if I got them exact, so there might be some intonation adjustment needed later. There will be sufficient slack in the piezo wires in the bridge cavity to accommodate any movement of the saddles during intonation adjustments.
     
    Last edited: Jun 8, 2021
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  12. GlenP

    GlenP Country Gent

    Jul 23, 2019
    WA
    Switch plates! Just picked these up from the trophy shop today.

    The metal plate is thinner, but I will have to cut it round. The plastic plate has a good metallic sheen to it, and black edges that I might bevel to highlight the outline, but it is thicker. So, I will have to pick one of these and then figure out how to fill the 1/2” hole accordingly to fit the 1/4” toggle. I really like the designs of the pilfered Gretsch headstock logos for the horseshoe magnet and the diamond/crystal for the piezo position.

    This switch plate is like the PIEce de resistance!

    97AC071E-857A-48B3-8B01-FB9F3A6D651C.jpeg
     
    Last edited: Jun 8, 2021
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  13. GlenP

    GlenP Country Gent

    Jul 23, 2019
    WA
    Just a test fit for now, I kind of like it.
    E0CD801C-8E02-402E-9727-E3996E23A449.jpeg

    Thanks @Henry for the idea to use icons!
     
    Last edited: Jun 10, 2021
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  14. LivingMyDream

    LivingMyDream Friend of Fred

    I'm super excited to see and read about your progress, Glen! Your description of the progress says that things are going very well, and it seems that you are anticipating the little things, like a little extra slack in the piezo saddle wires, really well.
     
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  15. GlenP

    GlenP Country Gent

    Jul 23, 2019
    WA
    Thanks! I am giving things a lot of thought, this is really a fun project, but I am mostly just making progress on the weekends, so it will take a while. The mini toggle actually can get snug enough in the larger hole if I use a larger star washer, so I might not need to fill the hole and re-drill it, but I do have a dowel just the right size for it.

    The battery box location is the next big decision, I think the body is actually thick enough to place that right under the pots near the jack, so I might be able to take advantage of that access prior to installing the box. I just need to decide where it looks the best on a relatively flat portion of the back. But I don't want the box to be visible at all from the open f-hole on the top.

    (PS - I also did get a sound-hole humbucker pickup for my acoustic, a Fishman NeoD, and man, blending that with the built-in UST piezo sounds great. I am going to use that for my first public performance since shutdown at a local Farmer's Market later this month, at practice I ran the humbucker into the amp and the piezo into a stereo chorus into the mixer)
     
  16. LivingMyDream

    LivingMyDream Friend of Fred

    Glen it all sounds great, and I'm really excited that you are going to get a similar sound on your acoustic-electric. The cool part of the sound hole pickup is that you could run 2 amps to get that cool electric and acoustic separation.
     
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  17. Henry

    Henry I Bleed Orange

    Apr 9, 2014
    Petaluma
    Very cool, I love it! May have to steal the idea some day.
     
  18. GlenP

    GlenP Country Gent

    Jul 23, 2019
    WA
    Not an actual wiring diagram, more of a conceptual layout, will re-draw the wiring schematic later, this is more for planning out the wire routing. Here is my concept so far. I think it makes sense to have the Mag Blend pot closer to the neck and the piezo blend closer to the bridge. I will try to fit the battery box in that area near the piezo pre-amp pot and the jack. I need access to the Control-X pre-amp during installation, either through the f-hole or the battery box hole for a one-time calibration of the phase switch and the trim pot for the piezo level to balance with the passive mag output, and if I ever change mag pickups, I might have to re-trim the piezo level again.

    I need to make sure the 3 position toggle is wired the correct way to match the plate icons, "up"/left is Mag only, "down"/right is Piezo only, middle is blended. Also, I want the Neck/Bridge blend pot to be full Neck in the CCW position, and as you rotate it CW, like an increasing Vol control, I want it to blend and pan to the Bridge. So, I will work out those wiring details next. I did not draw in any ground wires yet.


    Screen Shot 2021-06-10 at 12.53.40 PM.png

    I will draw the wiring diagram upside down, from the point of view of the bottom of the guitar, so I don't have to think backwards when I am looking at the lugs.
     
    Last edited: Jun 10, 2021
  19. Setzerhotrod

    Setzerhotrod Country Gent

    Age:
    60
    Oct 26, 2011
    Anchorage Alaska
    Most excellent!
     
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  20. GlenP

    GlenP Country Gent

    Jul 23, 2019
    WA
    First draft of my wiring schematic, don't have all the ground wires drawn. All my signal wires will be shielded cable and the shields will be grounded to the pots. I need to double check the orientation of the blend pot wiring to make sure it engages full bridge when turned full CW and full neck when full CCW, that just makes more sense to me. I am replacing the pickup-selector with the stacked blend pot. The original Master Volume and Master Tone will get the output from both the Control-X piezo and the Mags, so it can still act as a Master Volume of the Mag/Pie blend in the mono/both mode. In stereo mode, the piezo goes to the Ring and the mag goes to the Tip. So this is slightly different from the LR Baggs provided wiring diagrams for a Strat or LP, but I think should work fine for the Gretsch, and will use the existing mounting holes. I will need to add one small 1/8" hole for the mono/stereo push button toggle switch, which is mounted on the pre-amp board that the Control-X piezo pot is mounted to. I am reusing the existing treble-bleed vol pot and tone pot with the caps already in place.

    Screen Shot 2021-06-10 at 11.15.56 PM.png
     
    Last edited: Jun 11, 2021
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