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Thoughts/help with integrating piezo with magnetics

Discussion in 'Pickups & Electronics [BG]' started by Taylor Livingston, May 20, 2003.


  1. Taylor Livingston

    Taylor Livingston Supporting Member Commercial User

    Dec 25, 2002
    Louisiana, US
    Owner, Iron Ether Electronics
    First, I did search, and found very little useful information.

    I've been pondering whether to incorporate piezo into my custom. The builder tells me that he could make piezo saddles relatively inexpensively, but I would have the problem of having to work the piezo in with the magnetic system. So: any ideas?

    I know I'd need a buffer/preamp for the piezos, but is there a way to keep the preamp you were using for the magnetics and add in the piezos somehow? I'm up for interesting/practical/whacky (I'm always up for whacky!) ideas. I considered having the two entirely separate, with the piezos running through their respective electronics and to one output, and the mags through the preamp, into another output.

    I'll continue searching, but anybody that can help/shoot whacky concepts at me would be greatly appreciated.
     
  2. geshel

    geshel

    Oct 2, 2001
    Seattle
    Bartolini make a piezo buffer module. In my basses the piezos go into the buffer, then the mag blend + piezo output goes to another blend pot, then to the preamp (NTMB).

    So I think you could use that with just about whatever magnetic setup you wanted.
     
  3. Taylor Livingston

    Taylor Livingston Supporting Member Commercial User

    Dec 25, 2002
    Louisiana, US
    Owner, Iron Ether Electronics
    Thanks. :) So the piezos would be controllable with the existing preamp, yes?

    My name, btw, is also Taylor. We should start a Bass Players Named Taylor club/support group, to help deal with the pressures of being named Taylor. I don't know about you, but I looked like a girl when I was little, so my name further destroyed my hopes of being recognized as a male.
     
  4. geshel

    geshel

    Oct 2, 2001
    Seattle
    Yup, the tone and master volume affect the output of the piezos as well (whatever the mag/piezo blend puts out anyway).

    Huh! I haven't met too many Taylors in my life, and most have been girls! :) It never helped me that my last name (Sherman) is a more common first name than Taylor, and Taylor is a very common surname. I've been listed/addressed/etc as "Sherman Taylor" more times than I can count.

    It's funny because it used to be a big deal for me, always had issues with my name. Now I tend to forget about it completely for a while! You know, when people call your name you don't hear it as a word, it's like "hey!" - it just gets your attention and you completely ignore the content.
     
  5. Taylor Livingston

    Taylor Livingston Supporting Member Commercial User

    Dec 25, 2002
    Louisiana, US
    Owner, Iron Ether Electronics
    :) My last name is Livingston, and Livingston Taylor is, I think, a blues musician or something (I really should know, shouldn't I?), so that's led to various mix-ups in the past. I've got the paperwork for our Yahoo! group started. I'll just need your check for dues and we can get this thing going. ;)
     
  6. John East

    John East Commercial User

    Jan 10, 2002
    Oxford UK
    Owner of E-Pro & East UK
    FYI:

    I make two bits of electronics to deal with piezos which might help get where you want to.

    One has two sections consisting of a piezo buffer with gain preset and a 4 input mixer stage. This allows a few combinations if an EQ section is included, depending in which order you place things. You could have the mixer last in the chain and keep EQs for piezo and mag separate, or you could mix the mag and piezo and EQ both, for example.

    The other has two sections consisting of a 2 input mixer and a 2 band EQ stage. The mixer input buffers are fine for either magnetic or piezo sources. The EQ is a single stack with BASS / TREBLE / Pull for BRIGHT.
     
  7. David Wilson

    David Wilson Administrator Staff Member Administrator Supporting Member

    Oct 14, 2002
    Lower Westchester, NY
    John,
    is this the new version of the BTB-01 you mentioned a while ago on the Dudepit? Do you have more info on this?

    cheers,
    David
     
  8. John East

    John East Commercial User

    Jan 10, 2002
    Oxford UK
    Owner of E-Pro & East UK
    Yes that's correct David, I can email you some info or Steve will be able to help you on this one too.

    John
     
  9. Taylor Livingston

    Taylor Livingston Supporting Member Commercial User

    Dec 25, 2002
    Louisiana, US
    Owner, Iron Ether Electronics
    Wow! Nice to hear from you!

    Although I'm not a complete idiot, I think that's a bit much for my brain. If there's any more detailed information available (perhaps dumbed down for those of us who are relatively new to piezo setups), I'd be very interested to read it. I don't believe I've ever seen a push/pull concentric stack. That's pretty interesting.
     
  10. Oh, by all means go the piezo route, Conical. They are absolutely great. I just bought an Ibanez EDA905F, and they make the bass! Without them, the bass would still sound good, but, probably not much more than that. With them, they compliment the magnetic so well. To put it plainly, piezos allow you to dial in extra high end and growl in small or huge amounts. They can sound good by themselves, but, they can also sound brittle. I don't know the technical end of it, but, my bass has a piezo volume knob on the front, and a level trim pot on the back. It's also got individual trim pots for each string. I'm still experimenting with settings right now. Another great thing about piezos is the growl they give. This bass has insane growl for a 34" scale bass. I can dial in as little or as much as I want. I can't believe I waited so long to try them.

    Piezos are the way!

    Good luck.

    Mike :)
     
  11. Taylor Livingston

    Taylor Livingston Supporting Member Commercial User

    Dec 25, 2002
    Louisiana, US
    Owner, Iron Ether Electronics
    Thanks for the info/review, Michael. One more nudge in that direction!
     
  12. geshel

    geshel

    Oct 2, 2001
    Seattle
    I guess I'll chime in here on the option too - I've been pretty happy with the piezos on my fretless. On the fretted, I don't use them so much - half because they just don't sound right for what I'm playing much of the time, half because they aren't the best sounding to begin with. The fretless has RMCs, the fretted Shadows. The Shadows don't have as smooth a frequency response as the RMCs, and are also a bit touchy with the setup - sometimes a string will sound bad and I'll have to wiggle the saddle a bit. The high 3 strings sound pretty good on the fretted (closer to an EBG maybe) but the low 3. . .eh. On the fretless they all sound great.
     
  13. Taylor Livingston

    Taylor Livingston Supporting Member Commercial User

    Dec 25, 2002
    Louisiana, US
    Owner, Iron Ether Electronics
    Not familiar with that abbreviation. Do you mean ABG (acoustic bass guitar)or EAB (electric-acoustic bass)? I can only think that EBG would be electric bass guitar.

    I'm mostly a pick player. I'm interested in the more acoustic sounds with piezo. I do chordal stuff and tend to try to fill up as much sonic space as possible, so I'm hoping piezo will be another texture with which to experiment, as well as a nice way stay very clear without sacrificing tone. Also, I want to experiment with some special strings, like Acousticores, that necessitate piezo.

    If John or anybody else could explain the mixer stuff, it would be much appreciated.
     
  14. geshel

    geshel

    Oct 2, 2001
    Seattle
    Oops - heh, yeah, ABG is what I meant.

    I'm not sure about the 4-input mixer, what all the inputs would be.
     
  15. John East

    John East Commercial User

    Jan 10, 2002
    Oxford UK
    Owner of E-Pro & East UK
    > I'm not sure about the 4-input mixer, what all the inputs would be.

    (I meant to reply to this earlier, have been away)

    4 inputs are over-kill in most situations as the majority of installations are likely to need two mixer inputs, magnetic & piezo.

    I figured 3 inputs might be used where two mag pickups could be mixed electronically plus a piezo. Electronic mixing isolates the pickups from each and tends to sound a little more punchy.

    The 4th input is me thinking let's leave some 'headroom' here, it adds a couple of
    components, that's all!

    With regard to explaining the mixer stuff, briefly:

    Whereas mag pickups have similar impedances (single coils often around 7kOhms at 100Hz) which allows them to be mixed passively, piezos, to operate satisfactorily, need to 'see' or feed a very much higher impedance, 1MOhm or more, so that's why they have their own buffers or preamps. Then if the buffer output impedance was similar to a magnetic pickup, passive mixing could work.

    If piezo and mag pickups were mixed passively without a buffer, the lower impedance of the magnetic pickups would 'suck' a lot of the signal away from the piezo.

    And if the mag side had an EQ section, which usually have very low output impedances, the piezo signal would virtually be completely sucked away.

    So when it comes to mixing the signals together, if they are mixed via their own electronically isolated inputs (much like mixing microphones in a mixing desk), their exact impedance doesn't matter.

    Passive mixing of magnetic pickups is also fraught with difficulties as well, because in order to transfer the maximum audio signal they like to see a high impedance too. That's why amplifiers have high impedance inputs of course.

    Passive blend and volume pots are often 250K or 500K in order that the mag pickups see a high impedance. The problems come when both pickups are nearing full volume or the blend is nearing the centre click. Instead of the pickups seeing the 250K pot or blend, they start to see the lower impedance of the other pickup, and vice versa. In other words the lower impedances of the pickups are dominating the higher impedance of the volumes or blend. The net effect is that everything becomes 'very touchy' and small adjustments make a big difference. If the two volume controls or blend outputs are correctly mixed via separate inputs of a mixer stage, this effect goes away.

    Hope that helps to uncover mixing piezos and magnetics a little.

    John
     
  16. Taylor Livingston

    Taylor Livingston Supporting Member Commercial User

    Dec 25, 2002
    Louisiana, US
    Owner, Iron Ether Electronics
    Thanks, John. Do you have a website where I could look at your piezo products (and maybe see a price and specs)? I know of J-retro.com, but that doesn't have any mention of the piezo things.
     
  17. fivestringdan

    fivestringdan Supporting Member

    Dec 4, 2001
    Little Rock, AR
    Thank god!! You'll be hearing from me!!
     
  18. Taylor Livingston

    Taylor Livingston Supporting Member Commercial User

    Dec 25, 2002
    Louisiana, US
    Owner, Iron Ether Electronics
    Dan, we cross paths again, eh? How goes your 10?
     
  19. Bonzai

    Bonzai

    Dec 6, 2002
    Question for Geshel and anyone else that can answer it,

    When you talk about your RMC Piezos, are you talking of the individual Pow'r bass saddles? If so, how are they installed on your bass? What brand is the bridge that your using, that they're installed on? Thanks
     
  20. geshel

    geshel

    Oct 2, 2001
    Seattle
    Mine uses a Hanewinckel bridge, machined so that the RMC elements can fit in the saddles.

    The gold is the RMC piezo elements:

    [​IMG]