Sunday, 2 January 2022

Lastgasp Art Laboratories Sick Pitch King Jr.

 Schematic and setup guide avaiable HERE.

And as usual, don't hesistate to order some boards from Deadend Fx.




11 comments:

  1. Sold one of my internal organs recently (hah) so I could procure some LM565CN ICs on ebay in hopes of building this up. Looking at DEFx's schematic, and I'm curious what the omitted 7v zener that goes between the 9v and the CLR (that you omitted) is all about? Also the omitted 1m resistor to VRef on pin 3 of the 4558. Not trying to point out errors or anything, just wanting to understand why? Thanks again for all your work, Anders!

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    1. Yhe 1m Vref resistor was missing indeed. It is now added.:-)

      The zener connecting to the LED can be added but I usually omit it, It is only useful if you want the LED to get dim if your battery is getting weak.

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    2. Whoa. Did I just peer edit your drawing? Check out the big brain on me!

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  2. On the 7th leg of 4558, the chain to the ground is lost (10u+4k7). Will it work correctly without this?

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  3. Ouch! And unfortunately there are more mistakes...

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  4. Now the OSC switch has all three contacts closed - this is not correct. Pins 1 and 2 must be connected with a 100n capacitor. This capacitor is not connected at all now (from the 7th leg of the LM565, after the 1k resistor).

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  5. Built it, no success....checked the schem and finally got it working. The following corrections are needed:
    -add in series between O-T 9 A 10u cap and a 4k7 resistor, with the positive cap lead at pin 7 of IC1
    -add a 1M resistor between L and Q10
    -I added a 20k pot between B20 and G20 for frequency sweep as I do not intend to use an exp pedal
    -trimpot to be adjusted where noise is minimum.
    With these algood, working.
    Cheers!

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  6. Help me figure it out - when you turn on the OSC toggle switch, there is a constant sound, the pitch of which is controlled by the FREQ knob. Is that how it should be?

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    Replies
    1. my working PCB: https://photos.app.goo.gl/yLVpr4rFRy35DM6L6

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    2. Hi Mr. Shu, which software did you use to draw?
      I didn't copy your layout, since I already cut the board and yours is bigger.
      But basically three things need to be changed in order to make it work.
      - the capacitor at OP14 is a 1uF (never saw it polarized one of 1nF) and has to be reversed.
      - the 100nF at K12 is not connected, a Link has to go to pin3 of IC1
      - also from IC1 : pin7 , a 10uF (+) to 4,7k to ground is missing.
      Finally connect freq 1 to the third pin of the potentiometer so the sweep goes up from left to right

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