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passive, active with piezo all in one bass?

Discussion in 'Luthier's Corner' started by hurricanecary, Nov 18, 2004.


  1. hurricanecary

    hurricanecary

    Apr 23, 2004
    artist
    can i put a passive pup with active and a piezo i have a aguilar pre plus bart piezo buffer trying to put warwicks with riki neck position (setmour duncan) plus abm piezo bridge for a custom bass. is this even possible?
    sure would value your input, thanx, Cary
     
  2. PasdaBeer

    PasdaBeer

    Nov 2, 2002
    Santa Rosa California
    SandStorm Designs
    yup.could do lots of fun stuff with that.

    single passive/active switches for both sets of pups,

    pushpull volume to run the mag's threw the pre amp, stacked bass/treb.
    pushpull volume for the peizo, run threw pre/passive

    stacked passive tone ( mag ), passive tone (peizo )

    possibly a 3 way selector, full on, mag only, peizo only

    thats only 4 knobs , and a mini toggle :)

    im a bit on a tone control monkey, just an FYI
     
  3. FBB Custom

    FBB Custom TalkBass Pro Commercial User

    Jan 26, 2002
    Maryland
    Owner: FBB Bass Works
    It's hard to tell exactly what wiring you are after, but...

    The buffer effectively changes the impedance of two different sources so that they match, and can be blended and will sound good through your amp. The MPB-1 has 2 input channels: one for your piezo and one for a magnetic source. So, if you have more than 1 magnetic pickup, then they need to be blended before they hit the buffer and should have roughly matching impedances (i.e. one passive and one active won't generally cut it). It's hard to tell from your post what the magnetic sources are...

    The EQ happens after all the sources are blended and so it shouldn't give you any problems.
     
  4. hurricanecary

    hurricanecary

    Apr 23, 2004
    artist
    two warwick jazz type thumb bass actives, with S.D. made riki neck position humucker, and piezo bridge pup. how do they all come together?
     
  5. FBB Custom

    FBB Custom TalkBass Pro Commercial User

    Jan 26, 2002
    Maryland
    Owner: FBB Bass Works
    What you are planning on doing is mixing 4 pickups with 3 different impedance levels. My advice is generally "don't do that".

    If you must, you can obviously blend down the 2 MEC pickups passively (switch or 25k blend pot) to reduce your setup to 3 signals, 3 impedance levels. Not knowing the impedances of the different pickups, I would say you need 3 buffered channels. But if I were to guess, I would think you've got a shot at buffering the SD and the piezo and mixing the buffered outputs directly with the MEC signal since the MECs are low impedance and the buffer will likely be producing low impedance signals in the same range.
     
  6. hurricanecary

    hurricanecary

    Apr 23, 2004
    artist
    i was thinking of buffering the piezo &riki together like you suggested and down or closest to warwick level then using a trim pot on the warwicks up or at level needed at the same time, maybe by using a blend pot? or should i use trim pots? thanks your giving me a light at the end of the tunnel.
     
  7. FBB Custom

    FBB Custom TalkBass Pro Commercial User

    Jan 26, 2002
    Maryland
    Owner: FBB Bass Works
    It's kind of hard to figure out what you're trying to say here. Bottom line is that you need to match the impedances of the pickups. Your best shot is to buffer the piezo and Rick pickup and then find a way to get them to balance with the MECs. You might need trim pots to raise their impedance, you might not. I don't know the output impedances of the buffer or the MECs, and if I did, I don't know the math to get you exact values. If you don't know the math either, you're looking at experimenting...maybe for a long time.

    You also need to blend the signals, but that is a separate issue. My guess is you're going to have some combination of 4 volumes, blends, and switches, and then the trims on the inside for impedance matching if you can make that happen.

    There's a reason you don't see a lot of basses configured like this. There's a lot of soldering and jamming stuff in the cavity and you reach a point of diminishing return in terms of the tonal options you get in the end.
     
  8. Suburban

    Suburban

    Jan 15, 2001
    lower mid Sweden
    You can do more or less whatever you can invent.
    Just make sure not to put in too much room for adjustment, esp without discrete selections. If you do, you'll spend your day searching for that superb sound you had last gig...instead of playing music.