Monday, 1 April 2013

Culturejam Shoot The Moon

As with the original I've left a gap in the centre of the board for the LED and LFO to allow them to easily be bent to face each other and laid flat, ensure the LED and LDR legs don't short against any of the links or component leads in between.  Heat shrink tubing or electricians tape will be perfect to bind them together and stop external light from reaching the LDR.  If you don't do this remember you will need to box the effect or be in total darkness to test.

Info from CJ about his take on the Tremulus Lune:

For your enjoyment, here is a tremolo that is pretty much identical to the Tremulus Lune, but with 2 fewer LFO pots. I think 4 knobs for a tremolo is plenty, and if you like the idea of the Lune but think it's got too much going on, this project is one you will want to pursue.

Other changes I made from the stock Lune:

• I changed a few parts values to make them a bit more "standard"
• I added a resistor (R16) and cap (C7) to isolate the LFO from the audio path. It might be overkill, but I like to err on the side of caution to avoid LFO ticking.
• I ditched the 9v regulator. I see why it would be there, but if 9v is the specified input voltage, a 9v regulator doesn't really make a lot of sense. Usually you need to give a regulator a volt or two more than its rated output to get to work properly. So I just got rid of it.
• I switched the input and output caps from electrolytic to film caps. However, if you are making your own layout, you can still use electrolytics if you wish, of course.








And an even more simplified 2 knob version with switch to select sine or square wave and gain trimmer.




Video of Geiri's build of the 2 knob version:



81 comments:

  1. Looks very cool. I have been contemplating between the Tremulus Lune and other Tremolos and this one might be the winner.

    I would say that for a decent tremolo, the SPEED, DEPTH and SMOOTHNESS (shape) are "must" features.
    GAIN could be dismissed, I guess.
    SYMMETRY is also very cool as duty cycle pulse width.

    It's the SPACING I don't get and the Speed-Fine duality which could be hooked up on single knob.

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  2. Sounds nice,might build this one.Whats an LDR

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    1. A Light Dependent Resistor. Like these:

      http://www.ebay.co.uk/itm/271165618147

      Or for not that much more money you could buy enough to keep you in LDR effects for a long time:

      http://www.ebay.co.uk/itm/150733154657

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  3. Hi
    Ive never used LDR either, looking at the ones you have suggested the bulk lot are not in the range suggested on the layout, does this matter ??

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    1. I've just specified the one mentioned in the Tremulus Lune documentation, but the ones I linked will work fine. Rather than needing a specific resistance, it just needs a small amount with the light on, and a large amount with it off, and it will work.

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    3. Thanks for the info Mark

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    4. would these do?

      http://www.ebay.com/itm/261185615121?ssPageName=STRK:MEWNX:IT&_trksid=p3984.m1439.l2649

      Also, how crucial is the value? Is it better to stock up on say 5-10k and 100-200k or to have 2-5k, 5-10k, 10-20k etc but less of them? Just trying to stock up smart... :)

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    5. The actual value isn't as important (as long as you don't go for some of the much higher value LDRs like 200K light 10M dark). Bear in mind that the theory behind this is really simple. The LDR is in the signal path, so as the LED illuminates the resistance is reduced to the lower resistance, then when the LED is in the off state the resistance is very high and so causing the tremolo effect as it modulates between the two values in the signal path. 5-10K light 500K dark would work fine. As would 10-20K light 1M dark.

      Then the gain of the final opamp stage is set by the relationship between the LDR light value and the gain pot (or trimmer) value. If the values match you will get unity gain. As the pot or trimmer increases above the light value, the gain increases (pot value/LDR value)

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    6. Wow, this was a very handy explanation, Mark! Thanks for taking the time to go through it.

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  4. Yay, my vid made it on here..cheers! If you care to know, my 5yo daughter/princess/2nd boss made me include the stuffed buddies.

    I made the one in the vid with a 5mm super-bright LED and LDR from Tayda. As far as I can tell/can remember, this circuit is not quite as picky about the value of the LDR, unless you start getting into the extreme ends of the range(s).

    Very cool little tremolo circuit that please me, rather I'm needing swampy twang or chop suey.

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    1. Aaah so was it your daughter you can hear giggling in the background? :o)

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    2. Yep. I did a few videos that afternoon and she was being persistent with trying to get more cameos of her buddies and trying to wave a hand in the shot, haha.

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  5. I'm not to up on opto trems, is there a way to increase the speed and depth on this? like to get up to the speed and depth of a schallar? thanks!

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    1. You need to experiment with the values of the Speed and Depth pots

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    2. duh..ok, should have thought of that myself. sometimes the simplest solution is right :) I'll play with it and see at what point it craps out. I love the helicopter sounds from schallars.

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  6. Built the 2-knob version, love it! Verified!

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    1. Brilliant, thanks mate. Video added and it sounds excellent!

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  7. Thanks for this layout mate, I've just built it, but not getting any dry signal, which of course is required at lower depth settings.
    I'll recheck my build against the schem, but any ideas why only modulated signal would be coming through?
    Jesse.

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  8. Fixed!
    Dodgy 100uf electrolytic.
    :)

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  9. Quick question on the shape switch: which connection is which? 1+2 connected is sine or square?

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  10. Oh, and one more question. If I sub another TL072 for the 062 do I need to make any other component changes to make up for the higher power requirements or should it not matter?

    Wondering if a more efficient layout could be made with a TL074...

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    1. I'm guessing due to different rail voltages, you might get shorter battery life with 072.
      I'm not going to talk about noise because while I do know what's the general consensus regarding 072/062, I don't know the maths to back it up.

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  11. Is the gain knob a level control or does it actually add grit? If it adds grit, a master volume knob would be a good idea so one can take advantage of the gain section.

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  12. Love this pedal but having problems with loud switch pop - anyone else experience this? Any suggestions for curing it?

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  13. CJ's schematic specifies a 4558 for IC2 (IC1 in the schematic), any reason for using a TL062 instead?

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    1. The TL062 is a low power opamp that is particularly good to use as an LFO because there is less chance of getting clock noise using it. As this is simply and LFO there will be no difference in sound no matter what compatible dual opamp you use, but there could be an improvement where noise is concerned hence choosing the TL062. By all means use the JRC4558 if you have those to hand, if you get no clock noise then there would be no improvement using the TL062 anyway

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  14. Maybe you can help...I'm only getting sound when the speed pot is dimed. I've referenced the layout vs my board and its all correct. Any ideas? Bad ic's?

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    1. got it. brain fart. this thing rules.

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  15. I am having problems.
    1) I am getting no dry signal with the pedal turned on.
    2) The LFO LED (the external one, not the one that gets bound to the LDR) is not lighting at all. I have tried another LED in its place, same result.

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    1. Does anyone have any advice on this?

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    2. Fixed. Bad LFO LED and Depth pot

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  16. hmm, ok most functionality working totally fine but the signal is really gritty like it's going through a distortion pedal before the trem. i'll check my wiring. any clue what may be causing this?

    the LFO signal also seems to be a little wonky. on a strum, the trem is in sync with the LFO LED but after a second or so the correct speed sort of starts stuttering back to some sort of fundamental frequency that's always the same (same frequency as the leaking hearthrob, too).

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    1. nvrmnd. four connections in the bottom right of the board were all landed one spot low. can't believe it worked as well as it did. looks like i was sending 9V into the inverting input of the second 072 stage which i imagine is what was fuzzing it out so hard. not even sure where it was getting power from...

      works great now!

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  17. A reverse log (C100k) for speed and standard log for gain (A10k) makes tweaking a bit easier. Thanks again to M+M for all the wonderful layouts.

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  18. Also, mine has a loud switch pop, cured by putting a 100k resistor to ground on the output. It can be mounted on the switch if you can't fit it on the board.

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    1. can you post the 3PDT wiring diagram that you used for this project ?

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  19. Built this and I just get a very transparent boost. LDR/led lights up. LFO led doesn't. I used a JRC4558 and TL072 in place of the TL062. Not sure if that's the reason I didn't get any tremolo effect. Thought I'd mention it in case anyone else experienced the same.

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    1. Have you tried different leds in your lfo circuit? Might be a bad component.

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    2. Yes, I tried a few and just tried a TL062 with no change so it's in the bin now. I've not been too impressed by trems I've built and was giving this one as the last chance saloon so I think I'll just bite the bullet and buy one

      cheers Dave ;o)

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  20. Does anyone have any suggestions on how you might add a "reset" switch to this tremolo?

    Imagine, for example, I set my tremolo to the proper rate (say, eighth notes at some given tempo), and I want my tremolo to be in time. By the time I get to that point in the music, the tremolo might be off beat.

    Could I add a momentary switch to "reset" the oscillator? Maybe use a SPDT momentary switch like this one (http://www.taydaelectronics.com/1pdt-stomp-foot-pedal-switch-pcb-2.html) that disconnects the 9 V going to the board?

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    1. You could put a normally closed contact of a momentary stomp in between the top of the 100R and pin 8 which would then cut the supply when you step on it. The only problem is, I don't know if there will be any latency in the startup of the oscillator which may make it very difficult to get the timing right, and I'm also not sure if you will get any noise during the process. I suppose it's a case of give it a try and see what happens :o)

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  21. Would there be a problem putting the 3pdt in the rate LED path to act as both rate and power indicator or does the rate LED do something else in the circuit?

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    1. No problem at all doing that

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    2. Doing so creates one heck of an LED pop. I've seen the AMZ ant-pop circuit and thought about using in place of my LED daughter board, but wont it have an effect on the rest of the the rate bits?

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  22. After two failed attempts at a Swamp Thang, I decided to give Shoot The Moon a try. I get a straight clean signal but no tremolo. The LEDs light up but no pulse. The pots make the LEDs brighter and dimmer (except the pots work backwards) which does effect the volume. There don't look like there are any solder bridges or cold joints, any ideas on why the LEDs don't pulse and my pots work backwards? Any help would be extremely appreciated.

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    1. It's the two pot version, the switch also has no effect, I'm guessing that's because it isn't working properly. Thanks.

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    2. Well I got the LEDs to work (the 2k2 had a 2m2 instead, how I screwed that one up, I don't know) but no sound. The bypass works signal works but that's all.

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    3. I got the effect working but insanely low output. It was louder without IC1 but extremely low output. Any advice would be extremely helpful.

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    4. low output...i think there is a sort somewhere.....(if you hear the effect working)
      could you post your voltages?
      and why you took out ic1?this suppose to work with everything on-board.
      anyway.voltages and high resolution pictures could give as an idea on what's wrong

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    5. I have to get some alligator clips to check the voltages, I have a multimeter but I can't get a good reading with just the the probes, I'll see if I can get some good pictures later too. I did check my ICs in another effect and they work fine in there.

      The effect doesn't work with out IC1 actually, it was just the sound of the LEDs pulsing. It was out accidentally, I was checking different ICs and I forgot to put one back in. I go from straight signal with no LED pulse to pulsing LEDs with no sound. The previous issues with the build were a 2m2 resistor in place of the 2k2 and a 10uf cap instead of the 100 if that gives any insight to what I could have done.

      Thanks for the response, I appreciate your help. Hopefully I can get this thing up and working soon, I've never had this much trouble with a build before.

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    6. hi jim! how did you solved the low output problem?

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  23. Couldn't get a good shot of the board but the voltages are:

    IC1: TL072

    1: 4.35
    2: 4.35
    3: 4.15
    4: 0
    5: 4.15
    6: 4.35
    7: 4.35
    8: 8.71

    IC2: TL062
    1: 4.10
    2: 4.10
    3: 4.10
    4: 0
    5: 3.75
    6: 4.20
    7: 4.20
    8: 8.15

    That was with the pots fully clockwise.

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    1. These are the best pictures I could get, hopefully it can help. The purple circles on the back were spots I just noticed and took care of, I put new electrolytics in too, but no change. Also the trimmer seems to work backwards, full clockwise cuts out bit of signal I have. I have no experience with trimpots, so is that normal?

      http://i275.photobucket.com/albums/jj316/elessar820/IMG_1195_zpseda1ded5.jpg
      http://i275.photobucket.com/albums/jj316/elessar820/IMG_1202_zps5939498b.jpg

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  24. Soldered a loose wire and good to go. Well worth the trouble it took for me to build. Thanks.

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    1. hi jim! this is the first project that i had a problem... same situation with you...

      bypass is working... so no problem with the guitar signal, switch, etc...
      when engaged, no sound... both LEDs are working... i tried to adjust the trimmer and all pots but still NO SOUND... 1 weird scenario is that when i wrapped the led and ldr together, im not getting any changes in LDR's pin while on board using ohmeter... and then i found out the led is busted... changed the LED.. i checked if its working before i wrap it with the ldr... still no sound... i found out the led is busted again... i checked the voltage that goes to the led's pins... not harmful for the led...
      i tried to short the pins of ldr... i got a distorted sound of guitar...
      i even coated the PCB with led just to make sure that everythings connected...

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  25. Has anyone had trouble with LFO noise in this circuit? I just built this on a breadboard and I'm getting a "thumping" noise; sounds like a heartbeat at low speeds, and like a machine gun at high speeds. But I know from Geiri's demo that this shouldn't be happening. Any suggestions?

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  26. The problem's been solved, thanks to some help from folks over at reddit.com/r/diypedals! The problem was that I didn't have any 1uF capacitors on hand, so in the meantime I used my next-closest values: 2.2uF and 4.7uF electrolytics. When I took them out and replaced them with 0.1uF film capacitors, the thumping noise was gone.

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  27. Just wanted to make one more comment. I was having issues with distortion in this circuit (the 2-knob version), which I've solved. Particularly on low notes (on the low E string), if I hit the string hard, I was getting a "fizzing" sound. It was subtle (just thought it was ordinary noise at first), and the noise goes away fairly quickly, but it was definitely there.

    On the suggestion of someone at DIYstompboxes, I tried wiring up the LED (the one connected to the LDR) directly to 9V (with a current-limiting resistor, of course). Now that the LED was no longer connected to the oscillator, I noticed that I was consistently getting distortion, even on some of the higher strings. It seems to me that the LED was simply getting too bright, "overwhelming" the LDR. (My LED was a 3mm red from Tayda. The LDR was also from Tayda -- a Waitrony KE-10720.)

    My solution was to replace each of the two 1k resistors that connect to the LED with 10k resistors. Your results may vary. If your LED has different specs, 1k resistors might work just fine without distortion. Or you may need to go even higher than 10k.

    Hope this helps, if anyone ever runs into this problem.

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  28. Does Speed 1 need to be connected to anything?

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    1. No, cuz it's just acting as a variable resistor yeh yeh.

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  29. PLEASE HELP!!!
    got it working now.. but... output is too low... output volume rises when LDR is facing my lamp shade with white LEDs... what do you think the problem is? i have 3 suspects...

    *red LED is not bright enough - i tried 3mm diffused green led, same result-also tried 5mm super bright blue LED, no light!

    *voltage for LED is not enough to make it bright... i measured the voltage, maximum of 3.+ volts... im not sure if its enough?

    *LDR's sensitivity is too low

    PLEASE HELP

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  31. Hi, I'm new to all of this. Could someone please do a complete shopping list of components for the 2 knob version ? I'm having a little trouble myslef identifying averything on the schematic. Thanks guys =)

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    1. Hey bud, I recommend trying a smaller effect first to get to grips with identifying parts and stuff, and then move up to this. Maybe start with a simple boost like LPB1 or something.

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    2. This is nt really a difficult build... BUT, if you're getting into trouble just identifiying the different parts.... mayble yo should not build this effect yet.

      You have to deal with a ldr, leds and trimmers. So this is not a solder and plug build, and no way recommended for someone with little knowledge.

      J.

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    3. Yeah that was my thought. Maybe get a kit from BYOC or something first? I did that when I first started out and it was incredibly informative.

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    4. Had a few problems when i built this but finally found the culprit. One of the legs of my LDR had a shocking soulder joint and wasn't even properly in place. It is amazing how easy it is to make mistakes. Used a 3mm red LED and a this LDR (Photo Conductive Cell Resistor LDR 650nm RADIAL KE-10720) from Tayda. And it sound awesome. Perfect for playing Germ Free Adolescents by X-ray Spex.

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    5. As a note i will change the wave pot for a switch as the pot has no real blend of the two. Just been messing with this with a univibe, flanger, phaser, another tremelo w echo and a ROG 22/7. What a total Mind F&^*%. In psychedelic heaven.

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  32. Built this and it sounds great. However, I get a huge pop when turning on/off. Also, when turned on, I get a loud thud that is in time with the LFO. I added a 1m resistor from the circuit output lug on the switch to ground. Also, replaced both in and out caps. No help. This happened with the heartthrob pedal I built as well. Never could fix it. Any ideas? I'd really love a trem that does not have these issues! PLEASE!

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    1. Some things I did that helped a lot with my build:

      - Add a 1M resistor from the output to ground
      - If you have a pulsing noise that's always present, modify the two 1k resistors going to the LFO LED, to taste (I used 10k resistors, which worked well with my LDR from Tayda)

      Hope this helps and it works out.

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    2. Weird, the standard pulldown resistor values did nothing. But a 120k resistor on the output works perfectly! Thanks all!

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    3. Do you mean the output jack or the effect out?

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    4. I'll bet he meant effect out. At output jack, the pulldown would also be pulling the bypassed signal down...
      +m

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  33. Hey guys I ordered a printed PCB with the schematic of this pedal and I'm wondering where I could buy the IC1 and IC2 chips and what they are/what do they do?

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  34. Hey guys,
    Just wondering which way electrolytics would face as the 1uf input/output caps? Ran out of polys.
    Would this affect anything?
    Can socket them and swap later I suppose

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  35. Thank you once again for a great layout.
    I know I'm late, but I find a solution to pop when the LFO Led is used for engaged/bypass signal. In my case the pulldown resistor didn't worked, it reduced the pop but didn't remove it. I remove the jumper from ground to IC2 and add a wire from IC2 to the switch and I used BYOC tremolo wiring for the switch. This wire replace SW7 in BYOC tremolo wiring. If I understand correctly (I'm a noob) it also remove the LFO when the pedal is bypassed.

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  37. I see and understand the method for REMOVING the "spacing" control from the Tremulus Lune layout but is there a relatively easy way for me to ADD the "spacing" control to this Shoot The Moon layout (specifically, the original 4-knob Shoot The Moon layout)? I'd like CJ's mods but would like to have potentiometers for Speed, Depth, Wave/Smooth, Spacing, and Gain. Thanks (and my apologies for the editing mess...didn't see an "edit" option so I had to "delete" to revise...)!

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