fitting a shadow pickup

Discussion in 'Amps, Mics & Pickups [DB]' started by heymrbassman, Apr 13, 2003.

  1. I have got a new bridge recently and am interested to know some details about refitting my pickup. At the moment it is fitted a little looser than I used to have it and parts of the bridge wings are not fitting as tightly. The gap is uneven

    The sound from my bass has changed into a less focused and woolly sound. It makes sense to me to shape the wings better to acheive an all round fit then wedge something in there until it fits correctly.

    Is this correct?
    How do you tell if the pu is fitted too tight?

    I am really tempted to get a bassmax and powerpack. How do these combined compare to the Shadow pu with no preamp?
    Would it make more sense to just get the power pack and use it with the shadow?
  2. Bob Gollihur

    Bob Gollihur

    Mar 22, 2000
    New Joisey Shore
    Big Cheese Emeritus: Gollihur Music
    I would suggest using wood shims as I recommend for use with the Bass Max and a bridge wing that is too wide. The pickups are designed to have direct contact with the wood of the bridge; I cannot recommend anything that would actually isolate the transducer from the bass.
  3. Steve Azola

    Steve Azola Azola Basses

    Jan 23, 2002
    San Diego, CA
    I thought I'd add my 2 cents to this one. I feel the wood shims are a little unforgiving. The solid connection made by the wood is compromised by the mismatched slot areas on most bridges. The only way to assure a perfect fit is to file/sand the slot parallel, then a wood shim can be used. However I find a somewhat "flexible" shim is easier and even sounds better. A piezo pickup must be allowed to vibrate and not be clamped in place by a wooden shim. The foam tape Ken suggested works well, or I use a felt/velvet self adhesive material. It is very thin and can be further shimmed underneath with thin pieces of cardboard, provideng a perfect slip fit. Another benefit of these materials is their gripping action. Sometimes a wooden shim can allow the pickup to slip, and even fall out.

    When I started using the Bass Max pickups on my basses about 8 years ago, I needed to find an easy and reliable method for shimming. The pickups themselves vary in thickness and have an uneven contact surface, so I came up with the velvet thing, and it's worked great, actually improving the sound over a wood shim.

    When I sell Bass Maxes to my customers, I always include a little shim pack, for proper fitting. If anyone out there needs a shim pack, just contact me, I'd be happy to send one out. They'll work with any bridge slot type pickup.

    Hope this helps,
  4. Sorry Steve - I don't buy it. If a piezo pickup has to be free to vibrate, how do you explain the success of the glued in pickups like the Barbara or the pickups solidly clamped between the top of the bass and the bridge like the Realist? While You and Ken may like the sound that is produced by this kind of mounting, I question weather it is an accurate sound or rather just the kind of sound you are looking for. That is, letting the insulation of the foam and cardboard filter out the vibrations you don't like. Needless to say, I totally agree with Bob G.
  5. Bob Gollihur

    Bob Gollihur

    Mar 22, 2000
    New Joisey Shore
    Big Cheese Emeritus: Gollihur Music
    Ok. So I started playing bass in 1961, violin in 1958. You can do the math, but I am not pulling that out to insinuate that the number of years of musical experience necessarily makes one opinion more valid than another.

    If the pickup is designed for wood/wood contact, using a material of different density and characteristics is not what I would recommend. I certainly respect your opinion, and I am sure your suggestion is based on your own ears and instrument reproduction goals. I feel that a properly cut wood shim (which means NO voids) with possible preparation of the bridge contact surface, if needed, is the best general advice to give if the bridge wing opening is too wide. I always suggest a spot of glue against the wood/wood contact to enhance the stability of the structure.

    I am glad foam tape works for you and pleases your ears. Different materials will certainly influence the sound the transducer delivers in different basses and bridges. I would be concerned about making up anything beyond a very small space with anything other than the native bridge material. If I wanted to alter the nature of the native sound of the pickup in use, then I might look at alternate materials.
  6. Steve Azola

    Steve Azola Azola Basses

    Jan 23, 2002
    San Diego, CA
    Ok Bobs,
    I'll just mention this: If you have ever taken apart a Barbera as (I did when 1 of mine died) you'd see that the 2 piezo crystals per string are mounted to a vibrational structure, and not in any way glued, bound or clamped. In the case of the Realist, it's mounted under the bridge foot and does not do anything to stop the bridge from vibrating. My main point was to try to show how a wingslot type pickup, could be mounted without hindering the bridge vibration. The Underwood/Shadow are the most solid of this type of pickup. There is no movement inside the metal housing, and I just feel that if you shim them solidly, you're sticking a wedge in the wing slot thereby clamping the bridge movement. In the case of the K&K Bass Max, if you have ever taken one apart you would see that the 2 crystals are separated by guess what, a hard foam core, and wrapped in rubber shrink tube! The shim material I use is very thin, and the cardboard I use is folder stock, also very thin. The foam Ken suggests is thicker than what I use, but I know it also works well, especially for filling in under the pickup, as he said.

    I guess I should really admit that I haven't been working on or playing upright bass for 30 or 40 years, but I have been experimenting with amplified bass sound for the last 10 or so. I have used just about all the piezos available and put them in every imaginable place, using all kinds of shimming and mounting materials known to man, and have landed on what, I feel, works best for me. I also build my own piezo pickups for use on some of my instruments, and have learned what it takes to make them work.

    None of this stuff is etched in stone- pickups, basses, amps, ears, uses, all vary. I just felt it would be nice to share my viewpiont.
  7. jazzbassnerd


    Aug 26, 2002
    i suggest wood shims. The secret is old sax reeds. they fit perfectly. and there very easy to get because sax players are so picky about reeds.
  8. It seems to me that you've shifted the discussion from the pickup to how the pickups are constructed. While I have not taken a Barbera pickup apart, I have had to do repairs to Barbera bridges and there was definately something holding the pickup element to the wooden bridge. My previous comments were with regard to your statement "A piezo pickup must be allowed to vibrate and not be clamped in place by a wooden shim". The pickup is the product the user buys and uses, not the crystals it contains. You can't dismiss the Realist just because it happens to be mounted differently. The pickup is rigidly held in place by 2 pieces of wood under great pressure.

    Now, I must take exception to your statement that a wing type pickup could be mounted without hindering the bridge vibration. Please explain how this could be possible with anything other than a pickup with zero mass.
  9. Steve Azola

    Steve Azola Azola Basses

    Jan 23, 2002
    San Diego, CA
    Yes, the Barbera element is in fact glued to the top of the bridge, it was inside the element I was talking about. The crystals are allowed to vibrate freely. The Realist's mounting method, clamped in place by the bridge, does see much vibration in the top of the instrument. Much more movement than in the bridge wing slot. My comments about the K&K pickup were to illustrate that they use a foam/rubber material in its construction. And yes, anything stuck in a bridge wing slot will do something to the natural sound of the instrument, however we're talking about amplified sound, and my experiments show a solid object jammed in there has a lot more to do with a sound change than something that is fitted allowing some movement in that area.

    So, to the poor guy that started this thread and just wanted to know how to shim his Shadow, sorry if it seems like we got off on a tangent, but maybe it would be best to contact Shadow and see what they advise.
  10. Steve - This is one statement on which I can totally agree with you.;)
  11. Phew!
    Foam or wood shim. Either way it has to fit tight but how do you know how tight. Can these pickups be damaged easily?
  12. (1) WOOD
    (2) finger tight - don't use a hammer to drive in the wedges!
    (3) No - but don't abuse them.
  13. Bob Gollihur

    Bob Gollihur

    Mar 22, 2000
    New Joisey Shore
    Big Cheese Emeritus: Gollihur Music
    That photo is from an article in Double Bassist magazine from about four years ago. Based on a look in the mirror, I should add some gray to the beard and it looks like I'll have to enlarge the size of the forehead soon :eek: I'm 52.

    Good to meet you, too, Ken, you make some wonderful instruments.

    TO ALL: Pick up a copy of the latest Bass Player magazine (May 2003) and you'll get a peek at Mr. Smith and his shop along with a nice article.
  14. Chris Fitzgerald

    Chris Fitzgerald Student of Life Staff Member Administrator

    Oct 19, 2000
    Louisville, KY
    Large foreheads are a sign of excessive virility and intelligence. Just ask AHHHNULD SCHNITZENEGGER and old DURRL. Welcome to the club!