Viewing 8 posts - 1 through 8 (of 8 total)
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  • #6424
    Anonymous
    Inactive

    Greetings!

    I made a 3 loop effects strip, however my strip is not working great. A quick description though. 3 loops, each with 3pdt switches. I used this wiring diagram (http://tagboardeffects.blogspot.com/2012/07/true-bypass-looper-5-loops.html). I added a 9v input jack which I daisy chained to three other 9v jacks to provide some power distribution (9v input is connected to a PS to the 9v 200ma output). Each of the 3pdt switches is grounded to the receive ring of it’s own loop. LED 9v is chained along the 9v jacks, and led ground connected to the switch.

    It all works – no hums or buzzes, but… using loops 2 & 3 with a single fx pedal on each, they rob each other of signal. Which I don’t understand. Anyway the diagram i used has a buffer circuit added, so I thought that would help.

    I built a buffer, added it in front of the chain, again no hums or buzzes, but whoa – did it POP when engaging any of the three switches. I tried putting it at the end of the chain, same thing.

    I added a 1M resistor to the ground from the buffer and also to the 9v jack chain, and 1M between the tip and ring of both the input and output jacks.

    Still pops! I’m new at this, doing the best I can, but I am stumped here. Any thoughts that might help me?

    #6432
    wilkie1
    Spectator

    Are you using GPCB 3PDT wiring boards to facilitate construction of your looper pedal?  Without a complete wiring diagram of your build, I cannot tell you where to look for an error.

    #6433
    Anonymous
    Inactive

    Thanks Wilkie, I am not using   GPCB 3PDT. The diagram I used is this:

    http://tagboardeffects.blogspot.com/2012/07/true-bypass-looper-5-loops.html

    I just added the 9v jacks.

    #6435
    Anonymous
    Inactive

    I omitted the tuner jack, the buffer and the buffer switch. But the loops would sap the signal when engaged, so I tried adding the buffer which is when I started getting the POPs.

    pg

    #6436
    wilkie1
    Spectator

    Since you have made substantial changes to the schematic you have published, I cannot tell you where there is an error.  You will need to give us clear detailed photos with voltage measurements at critical points.  Also provide a drawn schematic of your build so we can tell what you have changed.

    You are working from a design that is not a GPCB product. The popping you are experiencing may be caused by voltage appearing in the signal path.  Without the tools requested, I cannot further assist you.

    #6439
    Anonymous
    Inactive

    Hi Wilkie,

    I completely understand, I thought this was a general forum and not restricted to GPCB products. Thanks for your comments, it gives me a lead 🙂

    smile, pg

    #6441
    wilkie1
    Spectator

    Yes, we will offer assistance for other projects as long as we are given enough information.  I am here to help if possible.

    #6445
    Anonymous
    Inactive

    Fair enough, I appreciate the advice.

    Anyway the answer is – 1M pulldown resistors to ground tapped into the audio signal into and out of the buffer. http://www.muzique.com/news/pulldown-resistors/

    Since I have no good technique to do that it’s mighty ugly, but it works, no pops, and the buffer keeps the signal steady.

    Looking forward to the new pcb’s – blues buster and ancestral apparition!!

    thanks, pg

     

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