Saturday, 19 December 2015

Lastgasp Art Laboratories Rattle Crow Restive Filter

Just saw this schem posted in the forum and thought it looked like a pretty cool effect. The original has a funky LED setup and uses the 3rd pole of the 3PDT to cut the 9V connection to the whole circuit. I have drawn this layout to fit our normal offboard wiring.

Info from manufacturer:


The "RATTLE CROW RESTIVE FILTER" (RC) is an effect pedal in which the filter is affected according to the size of the input.


Characterized by a wild and sorrowful tone.


The RC is a kind of auto wah, but it has hysterical and distorted qualities, a broken auto wah sound.





24 comments:

  1. Thanks
    for diodes do you recommend anything?
    and do you think 2n2222 or 3904 could be replaced here?

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  2. I'm not really sure. Haven't built it yet or found any info from somebody that has built it. I may try 1n4001, as I have some that are pretty close to that forward voltage

    The 2SC1815 is really cheap, check out the prices on eBay and Tayda. The 2N2222 and 2N3904 should probably work ok, but pay attention to the pinout. I drew this for the 2SC1815 which is BCE

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    1. Thanks, I'll get some 2SC1815. My multimeter's diode test shows a number but it doesn't seem to be vf.
      How do you measure the forward voltage?

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    2. I use my Atlas DCA55 to measure diodes and transistors

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  3. This pedal sounds so insane, I think some time I'm going to have to build one and test altering different components. I think someone else should first though.

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  4. Weird... The 5th pole of the footswitch is connected to the Input of the circuit and to Sens 3, right ?

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    1. If you're using the offboard wiring layout posted here on the site, then yes (assuming you mean the 5th lug since it's a 3 pole switch)

      I would run a wire from switch lug 5 to sens 3, and then a second wire from sens 3 to the board

      It's not that weird if you're looking at the schem because basically the sensitivity pot is just a volume pot at the front of the circuit

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  5. Thats an effect everybody needs :D

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  6. ...can't tell wether it sounds broken or it's ment to sound that way. Funny thing :)

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  7. Sorry guys, I noticed a couple mistakes in my layout. I've updated the layout and verified it. Please be sure to get the new updated layout if you're planning on building this, or if you already started I'll let you know what to change to fix it.

    Anyways this is a pretty cool pedal. It's not something that you're gonna use all the time, but it's pretty unique and lots of fun actually. I used 1N4001 measured at 0.6Vf and it sounds like the demo to me

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    1. Great to hear its verified. I'm one step closer to having enough in the que to put an order together. Nice work.

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  8. this pedal looks awesome- can't wait to build.

    beginner question here. i've successfully built 3 pedals on vero using the layouts on this site (thank you to everyone for being amazing resources), but always have an issue soldering multiple wires into one hole.

    this pedal has sense, freq, level 1s all soldered to the same hole. how do you go about this? i can't fit two tinned wires through the same hole, nevermind three. is there a special method for this? in the past i have soldered a clipped lead from a resistor into the board, and then solder the off board wires to the lead. thanks so much!

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    1. Solder your wires to the wire.

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    2. Most of the double links on the layouts on the site are jumpers, just save some of the leads you cut from resistors or capacitors, they fit 2 to a hole easily.

      For wires, you can either solder your cables to a lead or cable, (Id recommend securing the solder point with a short piece of heat shrink) or just use any free hole in the same vero row. If space is not an issue (as in "Im not using a 1590A enclosure") just add an extra column to the layout if needed, though thats never been an issue with the layouts ive followed from here.

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  9. Just take one wire from the board to one of the pots and chain lug one of all of the pots together. It's just a ground connection so you could wire them individually to another ground point if you wanted

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    1. Thanks, Travis- makes total sense.

      Outside of this particular layout, is there a time where you would need to solder >2 wires into one hole on the board?

      For example: http://tagboardeffects.blogspot.com/2015/10/madbean-harbinger-one.html

      Ex. SPD 1,2,4,5. This layout is a little (or a lot) over my head, but I don't see how these connections go to ground. In this case, do you need to wire them all to the same spot on the board, or can you daisy chain them in the same manner as described above?


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    2. There's never a need to put two wires into the same hole on the board. Since the pot lugs are bigger it makes more sense to just make the shared connection happen there.

      On the harbinger layout it's the same deal, except that is a dual gang pot. So link the specified lugs together on the dual pot, and then send one wire from the board to the linked up pot lugs

      Also, hope I didn't confuse you to think that the shared connections are ALWAYS going to ground, that just happens to be the case with this layout here

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    3. Didn't confuse me at all re: shared connections to ground- just wanted to make sure the same principle applied. Wow! This will really change how I go about reading these layouts. No more trying to jam multiple wires into the same hole!

      Thanks!

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  10. At first I couldn't get it to cooperate. Turns out that 100n cap. wasn't optional. Now it's alive and kicking. Thanks

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  11. really cool filter indeed. I'm thinking about testing it with a clean blend on breadboard.

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  12. I built this one on vero but i have problems with the transistor. I have the guitar signal on the collector but on the emitter nothing gets out. i measured the base connector : 0.01v. I used two 4001 diodes as supposed.

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