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BF-2 Internal Trim Pots?

Discussion in 'Effects [BG]' started by chips, Feb 4, 2006.

  1. Gday guys.

    I picked one of these up the other week, and ive read about these 3 internal trim pots. So i just opened mine up and couldnt find anything. Mine is the Taiwanese pedal too, not the Japanese. Any difference?

    And what do these pots actually control?

  2. tplyons


    Apr 6, 2003
    Madison, NJ
    My take is if you have to ask the question, don't touch a thing. ;)

    I have yet to hear about these pots but I'll take a gander when I get mine as well.
  3. yeh, i didnt touch anything. Just took off the bottom, and lifted up the board to have a look around, but couldnt see anything that looked like a pot. :meh:
  4. Found that in a guitargeek post.

    I just opend it back up, and found them. They look like a little black circle, with a phillips head screwdriver slot in the top so u can adjust them. However, they dont seem overly accessable (sp?) though, im sure you could get to them, one may be more tricky then the other two.

    I could see one labelled as RES (guessing resonance), another as BIA (guessing bias) and the third one i couldnt see any label.. but im guessing it would be gain (overall volume).

    Im a little too scared to try and play with them at the moment, and i cant really see how they would help me find a better tone. Plus im pretty happy with what i can get out of my purple little friend.

    BTW, would the BIAS be like a blend type of control? As in, how much of the effected signal is sent to the output or something along those lines?

  5. tplyons


    Apr 6, 2003
    Madison, NJ
    Hmm, I'll have to take a look at that soon. Couldn't tell you what the bias could be though.
  6. BF-2 trimpots control bias, resonance and clock frequency. There's no gain control.

    bias is adjusted to avoid clipping of the waveform. Turn it and you risk adding unwanted distortion.

    Resonance is in series with the external resonance control and is used at the factory to set the proper conditions for the oscillator.

    Clock frequency is for the bucket brigade devices, adjusting it may change the delay time, but it may also have adverse sonic effects.

    If anyone is planning to tweak these pots, make sure you mark the original position before you start so that you can return to the factory settings if you get into bother.
  7. Basstyra

    Basstyra Commercial User

    Apr 3, 2005
    CTO @ Two notes Audio Engineering
    I have the same in my Ibanez FL9.

    I lowered the value of the RES trimpot, making the external pot cover a wider range. This allows some crazy sounds...

    I still didn't touched the other, but they are labelled the same. I guess all the flanger share the same schematic (probably the one of the A/DA flanger)