DIY B.Blender, Easy Question (I hope)

Discussion in 'Effects [BG]' started by mpm32, Jul 3, 2013.


  1. mpm32

    mpm32

    Joined:
    Jan 23, 2009
    am a noob to building pedals but I can follow directions pretty well. I haven't used effects that much because I didn't like the tone suck. I found the B.Blender and I thought it would be a good pedal that will help alleviate that.

    I have made the PCB, populated the board and I am starting to do the off board wiring. I am following this picture;

    [​IMG]

    have a question regarding the yellow lead coming from the board pin 2 volume that goes to the switch.

    When I wire the volume pot, do I leave pin 2 of the pot unwired? or do I also run a lead from pin 2 of the board to pin 2 of the pot as well?

    The layout doesn't have the volume and blend pots shown. I am also going to wire in a 9v and I've changed the In jack to stereo.

    Thanks in advance for any help/guidance you can give me.
     
  2. chicago_mike

    chicago_mike Supporting Member

    Joined:
    Oct 9, 2007
    Location:
    Chicago - LA - Rome
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    Endorsing Artist : Genz Benz
    Well, once you get the pcb populated, you can start testing at that point. -- if you don't have access to a scope, your pc soundcard can be used as one. You can use Cubase as an oscilloscope even.

    Pots wiring, imagine the shaft of the pots are facing up...the lugs are facing the pcb, component side.

    Okay so volume pot middle lug. This is obviously your signal out. Its wiping between ground and signal out of the pcb so no, there is no "lug 2" connection to the pcb...its already there, with lug 1..basically.

    So yeah, lug 2, wiper, no pcb but like you have posted, it does go to the 3PDT.

    I built an fx loop pedal a couple years ago with eq and other fun options, similar to the x-blender. The most useful pedal I have.

    If you feel brave, you can add a 2nd 3PDT...to switch out the blending of the loop. I.E. Fx in series...no blending..or FX in parallel..and blending.
     
  3. mpm32

    mpm32

    Joined:
    Jan 23, 2009
    Excellent, thanks! I'll give it shot.
     
  4. eddododo

    eddododo Supporting Member

    Joined:
    Apr 7, 2010
    Rather than soldering the middle lug of the volume pot to the PCB where noted, I would solder the middle lug of the vol pot to to the Switch, where the yellow wire connects on the schem. So, basically, the yellow wire is now from pot Lug 2 straight to the switch.

    This would work because what you're doing with this setup is grounding the output, rather than grounding the signal.

    Ill double check what I said in the a.m, its a wine kinda night at this gig and I too am a rather noobian electronics enthusiast



    edit:
    I... well... I totally just scrolled past Chicago mikes post, sorry

    for what its worth, O.P, I have been learning electronics 'for a minute', and a good, super multifunctional looper blender extravaganza is a project I have been using as a canvas of context to learn the craft, as well as a tangible, obsessive goal. So, as I balked on my plans to document the progression, I'll keep an eye on this thread, and if you have any questions or ideas I'd be happy to use the opportunity to relate my findings and hopefully get some new ideas in the process
     
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  6. mpm32

    mpm32

    Joined:
    Jan 23, 2009
    So I've got it all boxed up. All I know so far is that the led lights up when I push the switch and it won't do so unless I have a 1/4" cable inserted in the In jack. So I know I have the battery bypass wired up right. I'll test it sometime today when I get a chance to get out to my rehearsal space (a large shed in my backyard, and yes the whole band practices in it, give credence to the term woodshedding)

    [​IMG]

    Test report later today.
     
  7. chicago_mike

    chicago_mike Supporting Member

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    Disclosures:
    Endorsing Artist : Genz Benz
  8. mpm32

    mpm32

    Joined:
    Jan 23, 2009
    Well, didn't work. I get signal when the pedal is off. When I click the pedal on, I can barely hear anything, the volume pot works, the blend doesn't seem to do anything.

    Thought I'd try the power supply that came with my boss pedal but that didn't help but then I think I read somewhere that boss uses a different power supply pinout center pin is negative.

    I double checked my wiring noticed that I had the locations for the blend and vol pot reversed, fixed those - still no good.

    Double check the polarity of the caps, I have those right. Not sure what else to check.

    Here's the board, I guess I'll unbox everything and check it over again. I ordered axial caps instead of radial but I don't think that should make a difference.

    [​IMG]
     
  9. eddododo

    eddododo Supporting Member

    Joined:
    Apr 7, 2010
    Show a pic of the switching if possible?
     
  10. mpm32

    mpm32

    Joined:
    Jan 23, 2009
    Here's a pic of the inside. Thanks for your help.

    [​IMG]
     
  11. eddododo

    eddododo Supporting Member

    Joined:
    Apr 7, 2010
    A couple q's:

    when you say you get signal with it off, you mean that the bypass is working, or that you're getting buffered output from the pedal though disengaged?

    Try replacing the opamps (good call with the sockets!) real quick, since they can get killed and since theyre mega easy to check first.

    If that didn't work, plug in, engage the pedal, and see if by 'messing with' the wires with a signal going through that maybe youll get it to 'pop on', meaning that some connection is bad, or something is shorting, or similar.

    Maybe this should have been second, but double/triple check the resistor values; that was the MOST common time eater and mistake made when I started prototyping.



    other than all that, ill keep staring at this as I have time
     
  12. mpm32

    mpm32

    Joined:
    Jan 23, 2009
    The bypass is working. I get clean signal with the pedal off.

    When I boxed it up, I didn't plan properly for the battery and I had to squish it in there, the battery case was touching something because I couldn't get the led to turn on. I wrapped the battery on electrical tape and the led came on. Maybe that shorted out the op amps? Or static but we've been at 90% humidity for weeks.

    Or when I tried to use the boss power supply?

    I'll try replacing those and I'll double check the resistor values.

    Thanks, I hope I can get this to work because its supposed to do exactly what I need it to.
     
  13. chicago_mike

    chicago_mike Supporting Member

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    [​IMG]

    If the pedal works in bypass, and you DO get the LED...then..most likely its your 3PDT wiring.

    Double, triple, quadruple check it..then..check it again.

    Also..IF the wiring to the opamps was bad, or they were in reverse..they would get HOT to the touch. HOT. Like tube amp HOT.
     
  14. mpm32

    mpm32

    Joined:
    Jan 23, 2009
    Thanks Mike, I think I follow but I have a question regarding the wire that goes to vol pot pin 2. I currently have this wired to the switch.

    In your diagram, where would I wire this pin?

    Thanks,

    Mark
     
  15. chicago_mike

    chicago_mike Supporting Member

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    Yeah, lug 2, wich is the blender output, will go to the switch...as effect out.
     
  16. mpm32

    mpm32

    Joined:
    Jan 23, 2009
    Hmm, not sure I understand. In the original diagram that I posted, Lug 2 goes from the vol pot to the center pin on the top row of the switch. If you look at the PCB, this pad is isolated, no traces come from it, so I thought that wire goes from the volume pot directly.

    So in your diagram, I take lug 2 off of the volume pot and attach it to where? The switch? if so which pin?
     
  17. chicago_mike

    chicago_mike Supporting Member

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    Oh sorry..what I meant to say is the pot middle lug goes to the switch.
     
  18. mpm32

    mpm32

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    Jan 23, 2009
    Awesome, which pin of the switch?
     
  19. chicago_mike

    chicago_mike Supporting Member

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    In the piccie I posted...bottom middle.
     
  20. eddododo

    eddododo Supporting Member

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  21. mpm32

    mpm32

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    Jan 23, 2009
    Had to leave it for this week. Away on vacation. I'm going to tackle it again when I get back. I'll post an update then.

    Thanks.
     

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