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Piezo/Mag phasing problem

Discussion in 'Pickups & Electronics [BG]' started by dlmarquez, Jan 10, 2009.

  1. Jan 10, 2009 #1
    dlmarquez

    dlmarquez

    Jan 5, 2007
    Manizales, Caldas, Colombia
    Greetings all, I am having a problem with the phase on my mag/piezo bass.
    I have a Dark Star mag and an LR Baggs integrated saddle-piezo.
    The piezo output feeds into a Cafe Walter PZP-1 buffer-amp.
    there is a pot that acts as a blend pot. Mag at one end, Piezo at the other with a detent at the 50/50 position.
    Here is what is happening.
    The mag sounds great at the mag only position. The piezo sounds great in the piezo only position. However when I try to blend them the sound out is very thin and trebly...definitely out of phase. I tried switching the Dark Star inputs and being a single coil it gets really really noisy when I reverse the leads. The DS is definitely wired correctly. When the Piezo inputs are swapped everything sounds great EXCEPT the A string seems to have no output.
    I don't quite know what could be causing the A string only to have no output since te Piezo is a single integrated piezo bridge.
    I'd love to hear your thoughts and ideas!
     
  2. Jan 26, 2009 #2
    Low Main

    Low Main Supporting Member

    Nov 27, 2004
    Massachusetts
    Reading what the pickups are on your bass, I was thinking: if you ever got that thing working right, it would be a great sounding bass!

    I am not an electronics wizard but I enjoy messing around on my own basses. Since I don't know much about the theory, I just follow directions and do what seems to make sense. Not afraid to solder when I need to.

    I tried a PZP-1 on a bass with a Baggs-type piezo under saddle pickup and a mag soapbar. That bass had a factory onboard preamp to blend the two. I thought the PZP-1 would be an upgrade over the factory pre.

    I tried hard to get the PZP-1 to sound good, but it didn't work out in the end. Walter was awesome with the help, as he always is. I went back to the factory preamp because I think there were issues with the impedance difference between the mag and the piezo that the factory pre was designed to take care of, but the PZP wasn't.

    I think Walter could and perhaps would build you a good preamp to blend your Dark Star and Baggs if he had all the values for the two pickups, etc. That's just a guess, though. I can't speak for his schedule or inclination to take on a job like that.

    Steve Rodby is a big believer in having custom boxes made to handle varying impedances from various pickups, including on his upright. There may be some info somewhere on that. Or maybe check with Bob Gollihur's site for info.

    The mag/piezo thing is a lot of fun when it's working well. I hope you are able to get your bass straightened out one way or another.