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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.





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40 comments:

  1. ashkan19 December 2015 at 18:21

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

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  2. Travis19 December 2015 at 19:05

    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. ashkan20 December 2015 at 07:03

      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?

      Delete
    2. Travis20 December 2015 at 16:53

      I use my Atlas DCA55 to measure diodes and transistors

      Delete
  3. BurgerCrisis19 December 2015 at 20:28

    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. nicolas.lesage5220 December 2015 at 08:25

    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. Travis20 December 2015 at 17:00

      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

      Delete
    2. nicolas.lesage5213 February 2016 at 05:42

      Late thanks ;)

      Delete
  5. Unknown20 December 2015 at 12:33

    Thats an effect everybody needs :D

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  6. PCL20 December 2015 at 13:03

    The schematic please...

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  7. Merhulsky20 December 2015 at 15:37

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

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  8. Travis20 December 2015 at 16:47

    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. Synsound21 December 2015 at 02:30

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

      Delete
  9. msj2721 December 2015 at 01:53

    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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    Replies
    1. BurgerCrisis21 December 2015 at 10:25

      Solder your wires to the wire.

      Delete
    2. Grem30 December 2015 at 23:30

      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.

      Delete
  10. Travis21 December 2015 at 02:05

    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. msj2721 December 2015 at 02:36

      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?


      Delete
    2. Travis21 December 2015 at 03:46

      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

      Delete
    3. msj2722 December 2015 at 04:32

      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!

      Delete
  11. Travis22 December 2015 at 05:02

    No prob. Have fun!

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  12. Synsound25 January 2016 at 04:10

    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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  13. KT16 February 2016 at 14:50

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

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  14. Unknown16 February 2016 at 17:08

    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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  15. P. M.18 May 2017 at 16:13

    ok, now my guitar signal is like a wha in the down position. When I touch the circuit with my finger i have bird scream, from a deadly eagle in the desert to a chickadee in early spring but nothing conclusive. Maybe it's not a guitar pedal but a duck call.

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  16. Travis19 May 2017 at 00:53

    lol I'm not sure what's wrong with your build but I built this and it does work just like the demo that I heard

    Did you make any substitutions?

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  17. P. M.19 May 2017 at 10:12

    Yes, I tried with other pairs of diodes and other transistors without forgetting to adapt B, C and E, i verified all values etc and checked again and again resistors, capacitors. And the wiring, hole after hole, jumper after jumper, wire after wire. I will find this. I WILL FIND!

    (Or maybe someone drawn the PCB of this one or the MASF Biloma?)


    By the way, thank you all draftsmen and commentators, I started musical electronic a year ago because of you, dear DIY community.

    Hi from France !

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    1. Travis19 May 2017 at 20:26

      Hmm interesting. I wonder if this circuit is a little fickle about op amp and/or transistor choices.

      I know for sure the layout works but didn't have to do any substitutions to get mine working so I'm not sure what that's about

      Delete
    2. P. M.31 May 2017 at 21:28

      after 3 weeks i can say I GOT IT !

      Delete
    3. Travis1 June 2017 at 00:51

      Cool, what was it?

      Delete
  18. P. M.1 June 2017 at 13:44

    I do not know. I made a new circuit, cleaner, with new components. It needed a micro-short circuit. Anyway, but I regret a bit not to hear the chickadee singing. Maybe to make a version on battery and with a small speaker in the palm of the hand, to modulate: https://www.youtube.com/watch?v=skoiJPe1iZo

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    1. P. M.1 June 2017 at 18:00

      i have an half idea with a cry baby...

      Delete
  19. P. M.1 June 2017 at 17:59

    I have a request : if someone can hack the MASF Biloma I will, we will, enjoyed to compare these two similar circuit.

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  20. Unknown7 January 2018 at 11:19

    Hi. I'm new in DIY and try to collect the parts for this build. 
    Are the caps realy 56pf? Only find them as 56nf here in Germany...

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    Replies
    1. Unknown7 January 2018 at 11:24

      Can I replace them by 50pf caps?

      Delete
    2. comc_cmoc25 June 2018 at 00:20

      Make sure you're looking at ceramic capacitors. Anything close will do as they're not very accurate anyway. A common capacitor value is 47pF. Just get like 10 and choose the one with an actual capacitance closest to 56pF.

      Delete
  21. maidico25 November 2018 at 00:48

    I've just finished it, it's just crazy! I got a bc169 wich has the same pinout, it works just fine, and a lm358 for the opamp, I find it to be more harsh and present than the tl072.
    Thanks

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  22. CFE15 March 2022 at 01:35

    I'm a little confused on the LED here. The normal offboard wiring diagram doesn't have the LED connection coming off the board. Should I just wire from Row D to the 2.2k resistor and then to the footswitch as usual, skipping the wire from the DC jack to the resistor?

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  23. plasmid12 April 2023 at 17:43

    This pedal is sending me to the verge of a nervous breakdown. I made it, boxed it - nothing (apart from bypass). So I breadboarded it - it worked (but I didn't take a picture) so I transferred the components to fresh vero and boxed it and it didn't work - again nothing. So, I breadboarded it again - nothing. I'm using all the suggested components and have been over it a million times. Anybody got any ideas or am I just being dim? I made the Last Gasp Green Monster to take my mind off it and that works fine. At wits end.

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