Saturday, 18 January 2014

Lotus Pedals THD+N

On a roll now :o)
Info from the manufacture about his original Jerkulator copy:

Short for Total Harmonic Distortion + Noise. The THD+N is a Lo-Fi Fuzz with with Harmonic Distortion measurement is excess of 80% which are sweepable between even order and odd order harmonic distortion.






49 comments:

  1. Without even reading your description I recognised this as a jerkulator copy, quite amusing really, I mean the people who buy tend to buy these exotic boutique pedals must read on various forums that they are copies?

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  2. It's a moot point here, though because the Harmonic Jerkulator is a DIY circuit and has never been available to buy. Furthermore, Escobedo asked that his work not be used in any commercial venture... Maybe the capitalised Harmonic Distortion in the description is meant as a nod to the origin.

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    1. True. And on the other hand, Jerkulator is just a work-alike derivative of Harmonic Percolator.

      From my personal viewpoint, a copy would be something with brand names in tact.
      +m

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  3. Hi Guys...I'm new at cloning pedals...i want to build one of the pedals but in my region i could'nt find any vero board that all nods in a row connected to each other...i want to know that is there a way that I draw the PCB from this blog's pictures of the board of the pedals?
    is there a software for doing this?
    sorry for my bad english....

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  4. Try this: http://www.taydaelectronics.com/catalogsearch/result/?q=vero

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    1. tnx man...but in my country i can't buy from this website :(
      i need a software to drawing the PCB layout to print it on a copper board...
      do you know that these circuit diagram build with which software?
      again sorry for my bad english...

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    2. This is the software I use, but you can only do very simply PCB layouts on it for transfers.

      http://diy-fever.com/sofware/diylc/

      I use the V2.x beta, just because I prefer it to the newer version.

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  5. hello to everyone!i have a small problem with this.i've build it today but i've used a 10uf instead off 22uf, and 47k pots for 100k cause i didn't had the right ones and i didn't want to wait till tomorrow....!i guess you unterstand how it feels...!!! the problem is that i can't take out any good sound, and as i can tell the rest of the connections are ok.pots don't act right at all.they are like 2 volumegains together...and the lever is really low.the "fuzz" is not a fuzz and i want to know if it will work with the right components from the layout, or if it should work with those i put too and i should look somewhere else for the problem.
    thanks for everything

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  6. I built this today and can't get any sound out of it. Well, there is a little sound but almost none. I am having a ton of trouble with these small circuits lately. I would anxious to see if anyone got it working. Thanks as always for all the work

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  7. It's such a simple circuit I'm pretty confident it's right. Have you included the cut between 22K resistors? What pin voltages are you getting?

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    1. I was certain that I was missing something obvious and had been looking at it too long. I figured my mistake would reveal itself after a dinner break.

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  8. Built one today…i have used all the right components , but it was just not working…@@… it made some strange sound

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  9. I've spotted the error. The collector resistor from Q1 goes to ground, not 9V, desolder that and put it to ground and it should work. Layout updated

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    1. first of all thanks for the fast reply…
      but i am a newbie ..@@ maybe i will just wait for the updated layout.,..

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    2. I updated the layout before I posted ^^

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    3. yup.. it works now….but to be honest ….it is super LOUD~! but it is not as "drive" or "Fuzz" as the real one (as you can listen from youtube)
      and it sounds quite smooth … quite creamy …

      thanks again

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  10. Hi!
    Equivalent for 2n3906? thanks

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    1. 2n2907 ? http://www.sonelec-musique.com/electronique_theorie_remplacements.html

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    2. Yes 2N2907 or maybe a 2N5087

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  11. Yep, that change did the trick. It's not bad sounding, either. Though it's not really a fuzz sound that I was getting - more of a nice distortion at most of the Drive levels. It becomes emaciated when you turn down the guitar volume but that happens with lots of pedals

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  12. Mark, you can mark this as verified. I just built it, and it works great. I have a strange problem though that I think is due to a bridge or something. When the gain is twisted CW the tone gets a little brighter the when its completely CCW.

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  13. So what do you reckon guys, verified or wait until any bugs are ironed out in the builds?

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    1. I think I did something, otherwise I think it can be verified. Do you think there's a bridge causing the gain to change the tone too, or do you think that's normal?

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    2. I mean normal for this pedal. Its hard to tell in the video is it happens.

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    3. I mean mine sounds really good, it's just not a fuzz. Is it just a matter of getting more signal to one of the transistors?

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    4. Hmmm. Mine definitely is fuzzy and nearly identical like it is in the original in the above video. Mine just has a tone change when you turn the gain from full CCW at "0" to anything above. Still trying to figure it out.

      Chee, mine is very loud too, and noisey like yours with the onespot, which I think is the reason for the extra noise. At lower volumes mine is more drive then fuzz, but when you turn it up past 12 o'clock it starts to get nice and fuzzy.

      Definitely a keeper for me even with the oddness mine is showing. Nice and creamy, overdrive to fuzzy goodness.

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    5. Good on you Johns~! i couldn't rise the vol knobs because of the crazy feed back and noise, maybe thats why it was not that fuzzy…

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    6. Hmmm, not sure. One Mine if the gain is full CCW I have the volume up full CW. Once I start playing with the gain I back the volume off to about 9-12 o'clock and it's a good volume boost besides the fuzz.

      Try it and see if that works on yours. Once I change the output cap, I'll come back with a report on how much the low end improves.

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    7. "One Mine if the gain is full CCW I have the volume up full CW" that makes sense, they are both essentially the same thing, the Gain pot dumps signal to ground at the input, the Volume pot dumps signal to ground at the output. So when the gain control is fully CCW the only thing stopping the entire signal from being dumped to ground and the pedal being silent is the 1K resistor at Gain 1. So it makes sense that you would have to compensate at the volume pot.

      So everyone's build should behave in that way or there is a build problem of some sort.

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    8. That's what I figured. I didn't think that was weird, what I do is the change in tone when gain is at "0" to anything "1" and above it gets trebly. I think it has to do with the change I made to the input cap, but not the output.

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  14. Just did some testing with mine one few days ago…
    and i have tired it with different amps(Orange dark terror, BlackStar stage 100 & Carvin V3M) and power supply(One spot & Joyo power bank)

    firstly, the pedal was extremely loud, and it is not that "Drive" or "Fuzz"….it was more overdrive sound from some vintage amp, sounds real good with blues stuff…

    however, i have meet a problem… i didn't know why the pedal was quite noisy, and especially i was using the one spot power supply, and i think maybe the output is kinda too high, so i made crazy feedback when i was trying with the Dark Terror and Black Star.

    and i am pretty sure that i have grounded everything well….but still….@@

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  15. What a weird bunch of differences from one pedal built by different people. Mine is a distortion but it is DEAD quiet with the One Spot. Eerily so. Maybe I'll swap out the transistors because I can't think of anything else that would change the sound any

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    1. Maybe it has to do with the transistors. I could see the hfe, and quality of the transistors making a difference. Maybe the higher the hfe the more distortion/fuzzy it gets. In my russian muff the hfe made a huge difference in fuzziness, output, and character of the fuzz.

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    2. hm… what kind of amp did you use? because when i first tired it with my small combo amp (Marshall MG15)… it was not that noisy, and some how it did quite more distortion sound….

      but i just didn't why it sounded differently with my three valve amps….

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    3. It's an old Fender Blues Jr 15 watt 2 EL84's. I was using a SG

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  16. Ok. Been messing with this one today and I think I figured out some of the problems with mine, and possibly the layout.

    First, if I put Q1 in and CBE just like the layout above, I get some hiss in the background, gets nice and fuzzy with gain at full CW, and the tone changes when the gain is turned CW from full CCW. I changed the orientation of Q1 to EBC, top to bottom, the pedal completely changes, IE: no background hissing at all, it does not get fuzzy, and no tone change when the gain is turned CW from full CCW. In fact, it sounds pretty much dead on to the video above, just bassier since I altered the input and output caps.

    I didn't see the schematic, but should Q1 be reversed?

    Second, I know it's listed as a fuzz, but the more I listen to it in the video and mine, it does seem more like an overdrive/distortion, up until about 3-4 clock.

    Pilt and Chee, reverse Q1 and see if that makes it sound right.

    Also, side note, I assume this can be daisy changed even thought Q1 is a PNP transistor. Am I correct?

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    1. Not according to the trace or the Jerkulator schematic. Both emitters are definitely connected with a cap to ground. Q1 collector has a resistor to ground, Q2 resistor has a resistor to 9V, same as the Jerkulator. You do have the latest version of the layout don't you with Q1 collector resistor to ground?

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    2. Yea, it's the same layout as above. I just looked at the schematic and you're right that it should be CBE. I just checked the board and its right too, no mistakes. Why could reversing Q1 make it sound correct, as opposed to the issues I had before? The biggest being a tone change when turning the gain pot.

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  17. This comment has been removed by the author.

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  18. Okay. I swapped out the transistors (same values) and it is more fuzz like. Much closer to the video sound. You get bloom with bends like a fuzz with the Drive on 11 (and it gets a little noisy, but not a troubling amount) So it's fuzz-ish for me but it might be a question of where that fuzz / distortion line is for me. At lower Drives, it's a nice sounding distortion, as I stated in an earlier post.

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  19. Hmm, I think my comment got lost whilst previewing it. But the short was - built it tonight, sounds like the videos, I like it, just waiting for some 1590a's to arrive to box it up!

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    1. Cheers Simon, I think with all the responses now it's pretty safe to tag this verified.

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  20. I've been playing with this one and I just haven't been satisfied with it. I tried it as-is in the schematic and it was really noisy, it picked up radio signals, and it just didn't give a good sounding distortion or fuzz for me. I switched Q1 as suggested by Johns, and it did get rid of the noise problem but I got almost no gain out of it, even when Drive was at maximum, and it sounded terribly thin. I switched both input and output caps and it just made it muddy. So I've scrapped this one altogether and am looking for another distortion. Thank anyway...

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  21. Hi, I'm working pedal at a given scheme and I think it's impossible to get the effect as videu.Radio frequencies are strong and I'm adding RF block capacitor of 150 pico circuit collector on Q1 and Q2.I am changed to input capacitor 22 nao to 47 nano and got stronger distortion. Noises which should be are still present.

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  22. is the collector resister for Q1 the 22k going to 9V+?just behind Q2?

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    1. Q1 collector resistor is the 22K to ground

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  23. Have to agree that we're missing something withe the schematic. I've built this thing twice with different transistors, pots, and caps and still couldn't get a working pedal. Lots of RF withe drive turned CCW., but pretty good sound at full CW. Anyone else have an idea?

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  24. Just finished building this. Getting a bit of hiss when drive pot turned up but other than that its not bad. Swapped Q1 round as mentioned in previous post and it does make it cleaner....weird. Mine is more like a very mild distortion than a fuzz. Might just double and triple check everything once more just to make sure my build is correct.

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