Friday, 28 October 2016

Paia 5730 Gator

Here is a great sounding Attack Delay / Noise Gate / Swell pedal.
I've used a more common LM13700 instead of LM3080.
You can find original project and scheamtic here.
I could not find any videos for this effect but there are some sound samples available here.
The original effect uses a momentary SPST footswitch.
I've also added an unverified true bypass version.
If you don't want the External Trigger just remove it and connect Thresh 1 to LM308 pin 2.




21 comments:

  1. Thanks for the layout, could you summarise the changes you made to convert it to 13700 from 3080?

    Also, the first layout has the 10M-to-ground bias resistor connected to pin 4 rather than +ve input pin 3.

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    1. 13700 is actually two 3080 in one casing
      There is a conversion board for those pedals that are build around 3080 since those chips are really hard to find http://effectslayouts.blogspot.ru/2015/11/lm13700-to-ca3080-conversion-board.хтмл

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    2. Well spotted! It has been corrected.

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    3. I've done this:
      LM3080 LM13700
      Pin 2 -> Pin 4
      Pin 3 -> Pin 3
      Pin 5 -> Pin 1
      Pin 4 -> Pin 6
      Pin 7 -> Pin 11
      I didn't use Diode Bias, Buffer In and Buffer Out.

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  2. Built the true bypass version yesterday. I am only getting sound when I jumper the 9V strip to pin 9 of the TL074, like hardwiring the switch in the original version. No swells though. I substituted the LM308 for a TL061 and the volume and threshold pots for 500kA because that's what I had on hand. I knifed the gaps, but haven't taken the time for a thorough component/placement check yet. I will try to post some voltages later today...

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    1. I think with TL061 you need to remove the 33p cap between pins 1 & 8.

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    2. Yeah, I forgot to say I already omitted the 33p. What I also did was wrongly place the 100n cap coming from the threshold pot, ahem. Once I fixed that there were swells abound :). I would consider this verified. I have to order some A250k pots though, the interaction between knobs is very weird now. It also seems the volume pot would work better with a linear sweep.
      Thanks for the layout!!

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    3. Oh, and just to clarify: I built the true bypass version without external trigger...

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    4. Well done Paul! Schematic didn't mention Log or Linear. Did you add 9V to pin 9?
      How does the pedal sound?

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    5. Like commented below I also left out the 9V to pin 9, it bypasses the effect. The effect sounds good, you have to adjust your playing to it a bit but there's a good range on the attack delay. The only thing I changed was the threshold pot, I ended up using a 50k. I think they used a large value to handle external signals but for my G&L tele with single coils it was only usable fully CCW.

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    6. Hi Paul, can you please explain what the external trigger is for and how you built it without the trigger jack?! I assume you just omitted the wires `Trigger Jack "C" and "S", but what about the wire that goes from `Trigger Jack "T" to Tresh 1? Thanks for that.

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    7. It's another input to the effect to control the gating.
      You can get all info from their original manual:
      http://paia.com/manuals/docs/5730pages_200.pdf
      The way to remove it is already explained in the introduction: don't connect the Trigger Jack and just connect Thresh 1 to where it says Trigger Jack "C" on the board.

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  3. Built the True Bypass Version, the second 1µF in the series pair to make 500nF in the bottom left is the wrong way round, flip it round and it's verified. I tried a 470nF and I can't say I noticed any difference, so I'd say that's an option too.

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    1. Cool. I'll change that. Did you connect TL074 pin 9 to +9V? How does it sound?

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    2. Haven't tried that yet, as far as I can see on the schem isn't that effectively just a bypass for the swells?

      It's pretty good, there's a bit of a noise floor when the gate is closed, but the LM308N I ordered in looks like a counterfeit, so it could be that, I'll get the LM308 out of my Rat tonight and give it another go. On longer swell times there can be some artefacts/distortion as it slowly crosses the threshold, but that's to be expected. 250KA for the volume doesn't seem like a great choice either, I'll try some others out tonight and report back.

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    3. 100kB makes a better choice for level I think, and the noise floor was down down to the dodgy LM308, with the good one from my Rat it's quiet as a mouse. If you want longer fade in times, just up the value of the attack pot, 1M gives you a good 5 or 6 seconds before the fade in even starts.

      Very good effect, much more consistent than the slow gear, and an easier build (In my slow gear all the transistors in the envelope detector circuit had to be matched, and even then it was temperamental)

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  4. Just FYI, the 1µF caps in the bottom left of the layout still aren't in series, the bottom one of the pair needs flipping around to make it verified.

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    1. Hi Robert.
      The way they are they should give a 500nF NP capacitor.
      Shouldn't they?

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  5. Hi, just built the true bypass version. As mentioned above, the lower 1uF cap of the left-bottom pair is flipped (wrong polarity). I used TL061 with omited 33p cap instead of TL308 and 100kB pot for level and it works like a charm.

    It's very unusual effect. With longer attack and with long-feedback delay after, it works incredibly for "Frippertronics" sounds. With shorter attack, it gives bowed "cello" sounds.

    Thanks for the layout... Some pics;

    http://s1190.photobucket.com/user/Sloup/media/DSCN4033_zps25srogch.jpg.html
    http://s1190.photobucket.com/user/Sloup/media/DSCN4036_zpsnqkgw34s.jpg.html

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  6. If you put two electrolytics back to back in series they act as a non polarized capacitor as Alex pointed out above. The capacitor is not backwards, it acts as a non polarized 500nf

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