Troubleshooting

Hey Todd

Happy New Years!

I think in my hurry to finish building the Party last night I must have done something wrong because any sample I record sounds like it was recorded with the Clock turned allllll the way down.  Everything is super aliased and crunchy.  Fiddling around Ive found that the Fine Clock pot works...fine...but the Course Clock pot doesnt do anything with the sample. Also Clock B isnt doing anything regardless of how I switch B1.  Before I take the case apart and figure out whats wrong, do you have any ideas where on the board I should start looking for my mistake?

Best,
-Reid

Comments

  • Hey Reid --
    If you gave yr WTPA2 too much bubbly last night, bets are off.  Unless it was Moet.

    Re-check your solder connections on VR6, especially the wiper.  Check associated resistors, then check VR7.
    If they're OK, check voltage at the wiper of VR6 or VR7.

    If you installed the 0-5v mod, it should go from about 0-5v.  If not it should be from 0 to about ~2.5v.

    Then check pin 3 of IC12.  It should go from about 0-2.5v or so.

    If those are fine, check that Q1's polarity is right.

    Clock B should only do anything if you're recording on Bank 1.  Does it do nothing on Bank1?

    -----------------

    I've got the first grip of preassembled units to test tomorrow.  I'll make sure they work like they're supposed to.  Could be my bad too.  I'll let you know.
    Thanks and good luck,
    TB

  • Hey Reid --
    So I found a stupid thing I did on the unit I built for the assembly manual.
    In the section on the 0-5v CV mod, I call out a 47k resistor being added between one side of R55 and ground.

    In the kit I built, and in the manual, I soldered down a 470 ohm resistor.  Dumb.
    The clock only goes very slowly when this happens.

    This is the picture in the manual.  Extra dumb.  I will rev the manual tonight.

    If you actually use a 47k where it says to, then the mod works fine.

    Also, since I was A/Bing 5v modded and non-5v modded kits, I noticed that adding the 5v mod makes the "FINE" control pretty insensitive.  So if you're only manually using the WTPA2, probably better to not use the 0-5v mod.
    (CVs from like 0-2.5v will still work fine).

    Best,
    Todd

  • Would it help to use a somewhat bigger pot value to make it more sensitive again?
  • Oh yeah.  There's lots of ways to make the circuit work slicker if you're willing to tinker.
    Changing the 100k fine pot to a 50k would probably help a lot.

    I'm thinking about fussing with mine a bit once all this shipping stuff is done.  If I get one that I like, I'll post the mod.
    TB

  • AHHHHH That explains the extra 47K resistor I have. I  am in the studio now and will report back if it works after I under the mod.  Thanks Todd!

  • And it works like a charm!
  • Excellent.  Glad that cleared it up!
    FWIW, I just built a batch of pre-assembled units with some different values to see if I could get the FINE pot a little less fine.  I'll report on that too.
  • edited January 2015
    disregard this comment :)
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