Stagg 3/4 edb replacement piezo pickups

Discussion in 'Setup & Repair [DB]' started by Peter Golden, May 13, 2019.

  1. Peter Golden

    Peter Golden

    Apr 16, 2019
    I need to replace the piezo pickups on my Stagg EDB the screening has become detached from the jack on one of them and the other is not looking good. Does anyone know the specifications or a source of supply to enable me to obtain a replacement
     
  2. sissy kathy

    sissy kathy Back to Bass-ics Gold Supporting Member

    Apr 21, 2014
    Arbutus, MD
    You might want to take this to the DB side of the forum.
    You need the dimensions of the pickup length & width at least. You can replace a shorter one with a longer one and trim to fit. The multi-element piezos are a little more complicated, but not much. If you get a thinner one you may need to shim the sides to keep the saddle in good contact. I wouldn't try replacing a thin one with a fatter one or a long one with a shorter one.
    Here's a rod pick-up, but only 65 mm long: Fishman Undersaddle Hard Piezo Pickup for Acoustic Guitar Red | eBay
    Here's a film pickup 3/4" x 6"! yes I said 6 inches long. Piezo film pickups
     
    Last edited: May 13, 2019
  3. Peter Golden

    Peter Golden

    Apr 16, 2019
    I have seen some on amazon with a length of 41mm is it as simple as cutting to length with wire cutters
     
  4. craigie

    craigie

    Nov 11, 2015
    calgary
    Good to know that fish man rod is easily obtainable. I put a fishman guitar pickup on my DB and a luthier pointed out to me the wire connection to the rod is fragile.
     
  5. On the Staggs the pickup is a piece of piezo wire connected to a cable running to the PCB.
    There is a clear tube around the copper shielding. If that got damaged, before getting something else as a pickup, I would try to repair that. Removing the clear tube is not a good idea, since the copper shielding might get off. I would try to put something around the clear plastic tube to hold things in place.

    This idea is a bit bad because piezo elements could be distroyed by heat, but I would at least try it before replacing the pickup completely:
    Get some shrink tube from an electronics store that is just a bit larger in diameter than the outer diameter of the clear plastic tube. Cut it to length, put it over the plastic tube and quickly heat it with a lighter. Just heat a part of it for less than a second, let it cool down, do the next part and let it cool down, etc.
    If you are lucky, the heat at the piezo doesn't cross the threshold of damage that way.

    If you have the elements looped (like with the newer Staggs), keep the loop before shrinking the tube, otherwise it might be hard or impossible to make the loop afterwards.
    The sound will be changed a bit, but any non-heated tube with a tight fit (like silicone) would change that a lot more to the dark side.

    Shrink tube is usually available as 2:1 and 4:1. That means the maximum shrink is half of quarter the diameter. 2:1 is usually easier to get, but the diameter should not differ too much from the clear tube diameter.

    For piezo foil you need a plan surface which my Stagg does't have. Otherwise you can easily destroy the foil. A wood shim below might help.
    I have cut piezo disks before (one part is OK and the other broken) but not piezo foil.
    For piezo foil you might need to put a shim on top and below to make room for the soldered contacts.
    Keep in mind that piezo disks and foil are mostly bending sensitive, piezo cable is mostly pressure sensitive. So a repair might be the better thing to try first.
     
  6. Peter Golden

    Peter Golden

    Apr 16, 2019
    Ok thanks I will look to see if I can repair the existing pick-up. If this is not an option what else can I do how easy is it to modify a piezo pickup to fit?
     
  7. You can use the bridge wing types and fill the rounded parts in the hole with some wood with a bit less thickness than the pickup's thickness and make a groove in one part for the cable.
    That would be easy to make but expensive. The cheap pickups are almost all made from piezo disks, since they are cheap.

    Piezo disks are not optimal, but can work. I used them for my pickups for a Clevinger EUB. The signal is a bit weaker than with other pickups, but if the pressure gets evenly distributed on both sides (that's why I used wood on top and below) the sound is good, just the impedance is high and needs an impedance buffer or high impedance preamp (10 MegOhms).
    Also I prefer to use an impedance buffer individually for each pickup (the Stagg electronic does this too as far as I know), the sound is better that way.
    Here are some (bad) pictures of ne of my pickups:
    image.jpeg image.jpeg
    As you can see, there is a groove in the thicker wooden part for the cable and the solder points inside. The brass side is glued to the thinner shim, the thickness of the piezo is compensated outside the ceramic layer with cardboard (on both ends).
    At the end the cardboard is glued to both sides, brass/wood shim and thicker wooden part and lightly clamped until the glue has set. It would even be possible to reopen it by cutting through the cardboard and probably replacing the cardboard before the parts are reglued together. Don't forget to glue the cable to the thicker wooden part to avoid stress on the solder points.

    The hardest part is soldering the shielded cable to the piezo disk (shield to brass, hot to silver coating), since the piezo material looses the piezo characteristics when it gets too hot. (No longer than one second with 170 to 180 degree Celsius with old solder containing Pb, silver solder needs higher temperatures.)

    Get the biggest disks you can find, you can cut them with a scissor, but the right side of the cut will be unusable. I do two parallel cuts for the sides usually. Smaller disks work too, but then the pressure needs to get on that area. For that pickup, I think I have used a smaller or medium sized disk.

    But this is some work, I would first try to repair the existing pickup.
    But I really cannot understand how such a damage has happened. If it's only the copper fiber ends sticking out about a mm that is OK as long as the clear plastic tube is intact.
     

    Attached Files:

  8. Peter Golden

    Peter Golden

    Apr 16, 2019
    Thanks again for your good advice I have seen a piezo wire attached to a input jack on amazon it’s looks a lot like what has been fitted with the exception that the exposed wire that goes under the bridge is longer l. I am thinking of sheiding the excess wire insulation tape this avoiding the heat problem and pulling the excess through into the preamp compartment. Seriously thinking I may replace both at the same time. Also have seen photos of the later configuration where the wire is looped under the bridge I would have enough wire to do this. Has anyone compared the two designs to know which is best
     
  9. I think the change is mostly simpler manufacturing, since for the earlier design the was a groove for the piezo cable and during assembly they need to make sure that the stiff cable sits in the groove and not beneath.
    The loop might be less sensitive to an angled bridge, but then with more pressure on one part of the piezo cable than with the bridge perpendicular to the body.
    Hard to say what is better.

    I have both, but the new body without electronics, so I cannot compare them soundwise. I changed necks because the new one that I got cheap had a rosewood neck.
     
  10. Peter Golden

    Peter Golden

    Apr 16, 2019
    Thanks again it’s always good to get sound advice. I have ordered a couple of replacements which will be with me by the 11th June. I will let you know how I get on
     
  11. Peter Golden

    Peter Golden

    Apr 16, 2019
  12. HateyMcAmp

    HateyMcAmp Supporting Member

    Apr 13, 2006
    Queen City of the Plains
    Krivo Pickups
    If this ends up being a really intractable thing, you can always mount a Krivo magnetic pick up on the end of the fingerboard. You won’t have access to the preamp or the headphone amp, but it will definitely work.
     
  13. John Le Guyader

    John Le Guyader Supporting Member

    Jun 6, 2006
    DC Metro
    If it were me, and I use to own a Stagg EUB, I'd get one of these and pop the sensors on the bridge and figure out the wiring later (no preamp needed): prestige-220

    I used this on a Warwick Alien acoustic bass and it sounds great with no preamp.
     
  14. The thick Stagg bridge won’t vibrate too much for piezo disks glued onto it.
    I would prefer the wire or any other piezo under the bridge feet.
     
  15. Peter Golden

    Peter Golden

    Apr 16, 2019
    I have now fitted the replacement piezo wire pickups along with the active 1/4 output socket and the screened wire from the socket to the preamp 8 years of gigs have taken its toll. Will spend The next week settling up the sound before playing it out at my next gig. Thanks to everyone who has commented. Will let you know how I get on
     
    HateyMcAmp likes this.
  16. Mister Cbass

    Mister Cbass

    Jun 30, 2011
    France
    interesting topic, I've just bought a stagg, and I read a lot the different topic related to it ( strings, upgrade etc ).

    The stagg is setup with an adjustable bridge. What about a pickup like the full circle or
    https://www.thomann.de/fr/david_gage_the_realist_regular_life_line.htm

    Expensive solution, But will it work on a eub ? maybe that the result will be positive. Of course the preamp / headphone and aux inputs will become useless.

    I've read nothing about this type of pickup on a stagg or another eub ?
     
  17. Because they won’t fit or work well.

    Anyway, the better solution would be to replace the bridge, then you can install what you want. But a normal DB bridge won’t fit (too high), so you need to make your own.

    The built-in piezos are not that bad, electronics can be noisy (not mine, except when using the line in), but there are instructions on Talkbass to cut off anything after the initial buffers.

    IMHO the bridge is rather bad, grooves not deep enough, adjusters too heavy, too bulky, bridge crown cannot vibrate from side to side like on a DB. So much too stiff. Useable for starting, but better to be replaced before finding better pickups.

    BTW, in the Electronics you can find two pots to adjust volume for high and low side pickup. You might want to experiment with that first.

    And unless you also bow a 5-string DB, the Stagg EUB is hard to bow because of the low fingerboard/bridge curvature (and because it is a solid body instrument).

    There are more important things to tweak on a Stagg EUB than the pickups, but you can tune down the strings, pull the bridge out and adjust the position of the piezo cables. And always (!) make sure the bridge is perpendicular to the body. Otherwise the contact with the piezo cable can be bad.
     
    Mister Cbass likes this.