Monday, 29 April 2013

EarthQuaker Devices Hummingbird

It's a modded Vox Repeat Percussion so more use for those 2N2646's you stocked up on.

Info about the original:

The Hummingbird is, at heart, a hard and choppy tremolo. What comes out is more akin to vintage synth style oscillations. It's core is based on the old Vox Repeat Percussion with several updates to reduce noise, enhance the "chop" and add more control. It can create ring mod-like octaves, slow pulses, ping pong delay-like stutters, light blipping through machine gun stutter tremolo and many more wacky sounds!

Controls:
Depth- Controls amount of modulation from barely there to full signal chop.
Rate- Controls the speed of the LFO
Level- controls the input/output level
Mode- fast/slow switch for LFO rate







151 comments:

  1. I can't remember if I ever got around to ordering the 2n2646s, if I haven't I'm definitely going to now. This looks a lot more versatile than the Repeat Percussion.

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    1. I ordered 14 for some bizarre reason! :o)

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    2. £3?!! £3 for a single f***ing transistor?!

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    3. Damn you ebay! *shakes fist*

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    4. I hope you got them cheaper than I can find them for Mark.

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    5. Send me your address on FB and I'll send you one

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    6. Cheers! I can't imagine I've got much that you'd need, but if you think I might just say the word.

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    7. Holy Moly! I bought fifty 2N2546 from The States last year to do a Repeat Percussion for ten dollars! If anyone wants any please ask.
      Hate to name drop but there is a certain Spacemen 3 guitarist friend of mine who's going to love this!

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    8. Could i have one of those 2N2546 from you IvIark? im just sayin. Greetings from Mexico

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    9. Send your address to guitarfx at hotmail dot co dot uk and I'll send you one, but only because I love Javier Hernandez (sorry Rick) and thought Mexico and Mexicans were awesome on my honeymoon! :o)

      The free shop is now closed though or I can see this going on :o)

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    10. hey beaker, can i get one of those?

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    12. I'd love some of those trannys, if it's no trouble at all to you Beaker.

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    13. Email my your address Christian, and I'll sent you a few.

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    14. Sorry guys but sent out quite a few trannys now so can't afford any more requests for more.

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    15. IvIark thank you for the transistor finally the one that you send me arrived this week, maybe the postal service is not as good as in your country, i will be working on this and i will let you know how its going thanks man

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    16. Holy shit! A whole nyear???? Sheer madness!

      Por lo que veo, los servicios de correos funcionan igual en todo el mundo :P

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    17. Wow, I could have rowed there myself in that time! :)

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  2. More EQD stuff please! Hoof would be awesome!!!!

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  3. Ok, built this up this afternoon, works as it should but not as quiet as my vox repeater, i`m getting a pulsing whistle from it, a j201 made it slightly quieter and a mpf102 made it really quiet but highest level was below unity. I`ll see what it`s like when boxed. Is it better than the Vox? IMHO, no. It`s basically the Vox with a level control but without the tone switch. Build the Vox, experiment with caps for the rate switch and use your guitar volume for the level control.

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    1. The problem I have with the VOX is that it is really loud. As soon as it's engaged, the volume jumps significantly. I took it out again last night after the Hummingbird was posted and it sounds fantastic, but the volume thing bugs me. Any cure you know of for that?

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    2. Add a little volume daughterboard addon, set the level you want and forget. As per the bottom of the Offboard page.

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    3. Holy crap, how simple is that? Simple and elegant. I never noticed it before. I need to pay more attention. Thanks.

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    4. Have to agree with Dexxyy.

      Extremely disgusting pulse whistle on all settings, at high rate & depth you can notice it even louder than the guitar sound, and on high speed mode is just unbearable.

      Don't know what can be wrong, but this pulse sounnd can't be heard on demos.

      BR

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    5. Ooh, Q2 is the wrong way round, did you both correct that?

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    6. And 4u7 needs reversing. Jeez I was having a bad day here! :o)

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    7. So Q2 is not a DBA influence? :P

      Which 4,7 cap you mean? I suppose the one at the lower left, but just to be sure :P

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    8. Yes I've corrected the layout now

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    9. Yeah! Now it works great and as it should! Great job again Mark!

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  4. By the way, 2N2646, 1.25€/piece in Madrid, if someone's interested, just mesage me!

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    1. Man, I was happy with the "Shoot The Moon" tremolo but this is tempting. I might be interested in this offer. They're so expensive on eBay!

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  5. This sounds really cool, im gonna have a go at it.

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  6. Just a comment. This effect is EXTREMELY sensitive to power source. With battery is dead silent, but with power supply (I use a Spot 1, really good PS) you get a f*cking hum.

    Have to try with a bigger power filtering caps to see what happens, maybe a 470uf.

    BR

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    1. Did the usual trick: 220R + 220uf cap on +9 and now is dead silent with power supply too :).

      I tried before the trick a not very good PS that I have just to feed an external dvd recorder, and there was no sound, just a incredible hum, so it seems to confirm that this pedal is extremely sensitive to rectified DC. Take this in mind!

      BR

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    2. Do you put them in parallel before the +9v? What is this magical trick of which you speak?

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    3. Just run the power through a 100R or 200R resistor and then have a 100uF to 1000uF cap to ground.

      draw power from just before the cap and you will get clean DC that won't buzz/hum.

      Here, http://www.beavisaudio.com/projects/Huminator/index.htm Omit D2(The LED), C2, R2. Put that in the front of any circuit that doesn't play well with bad power supplies and you have reverse voltage protection and filtering.

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    4. Please can You elaborate that a bit. What do you mean by "run power trough" and "cap to ground"? You mean outside of the board or on board? Please can You be a bit more accurate? Mine is very noisy on PS on batt is silent...I know that huminator but I would like to do it in pedal it self...

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    5. Take the red wire from the dc jack and solder it to one leg of 100R or 220R resistor. Solder a piece of red wire to the other leg and use the remaining end of wire as +9V for the board.

      Swap the 100µ electrolytic on board for 220µ.

      That's it.
      +m

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  7. Is there any way to use this with an expression pedal?

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    1. or a function something like the pigtronix tremvelope that makes your speed increase or decrease after pick attack.

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    2. so an envelope controlled depth or speed.

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    3. I've been wondering about that for a long time, I've wanted to make an envelope controlled tremolo for a while.

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    4. or a tap tempo mod would be nice. I don't know how I'd ever get it in sync without having to bend over and fiddle with it after the song has already started.

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  8. Built this, can't get it working. The signal goes through fine but there's no tremolo happening. The only two things that aren't exactly as the layout are the 2N5089 and 330K. I used 2N5088 and 340K but that should still work.

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    1. Yes, me too Geiri. Got the same problem here. No tremolo happening. Only bypass signal. The only thing that work is the level control. Any issue with the layout Ivlark? Mind sharing the schematic? Many thanks. :)

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    2. Don't know guys, but mine works like a dream

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    3. Just take a close look to the 2646 trannie:

      https://www.google.com/url?sa=i&rct=j&q=&esrc=s&source=images&cd=&cad=rja&docid=a4ePcVPOXorosM&tbnid=WBLScDZtXdfg2M:&ved=0CAUQjRw&url=http%3A%2F%2Fwww.sentex.ca%2F~mec1995%2Fgadgets%2Fujttest.htm&ei=eEa7Ua-3AaSW0AWKyIGICw&bvm=bv.47883778,d.ZGU&psig=AFQjCNEyHgjduPQ-2CwDsYgxG7jJfdGpEg&ust=1371314071084386

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    4. Hmmm... is it normal for 2n2646 to go bad just like that? How to test this kind of transistor? May I know what brand of 2n2646 did you use, JaviCAP? Mine seems to have no other markings except 2n2646. Many thanks.

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    5. Thanks for the link. Will do the testing later. :)

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    6. I'm opening a topic on the forum with the pics.

      BR

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    7. Built this today, and i'm having the same problem, no tremolo at all, just a clean sound. Everything looks fine to me, no solder bridges, and components are in correct places. Can someone help me? Thanks

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  9. I just built this... and for a second I though i'd gotten really good at guitar... but then I started wondering how I was making the drum sounds... and realized that this pedal is just the best radio I've ever heard...

    Wait, it wasn't suppose to be a radio? Oh... well crap... let me just... oh oh I get it... don't @#%$ up and swap Q2 with Q3. Unless you want a kick ass radio...

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  10. Another verified build, sounds wonderful!

    I bought some NOS metal-can Motorola 2N2646 transistors from ebay, worked flawlessly. The only trouble I ran into was because I forgot to solder the diode, without it there's no tremolo. I used a 1N914 diode and that worked just fine too.

    Build this one right away, fast mode gives you a kinda psuedo ring mod and octave down effect.

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  11. Built it, works as a charm. Thanks, this is the tremolo that goes into my board!

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  12. Hi guys, only just got round to finishing this. Works as it should, but has a pronounced "ticking", more noticeable at fast rate. Anyone got any ideas what's up?

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    Replies
    1. Need new glasses - completely forgot the 22n cap.

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  13. anyone have any 2n2646s? i'll gift you some paypal money for your troubles!!

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  14. From my point of view, I have no tremolo but only some dry signal with the volume all the way up
    Is it possible that the type of 2n2646 affects the circuit?I bought two, but if there are not suppose to work with the first build, then why should they work with an other build..?
    Also could someone mention the voltages on the 2n5089 please.

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  15. I have a very similar problem with a Repeat Percussion with depth pot that I made with the layout here. Not sure what I did wrong, but I subbed two resistors for slightly different values that I had on hand

    If I figure it out I'll let you know, but I'm thinking of just scrapping it and starting it over

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  16. HI,

    I have a ticking problem. When switch is in fast mode ticking is present and on slow mode it does nothing just passes dry signal...can someone help me with this one? I have done humm free mode from above but it is same with or with out it....

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  17. Mine works great but the dry sound is slightly darker than my bypassed sound. Does anyone know how I would go about making it a tad brighter? Thanks.

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  18. first of all thanks very much for the layouts and for this site it's been really helpful.
    i 've built it but there is no tremolo. only the original signal. the volume pot works. the depth pot does nothing. the rate pot seems to to amplify the signal when turned all the way up. used the exact components as specified. please help.

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  19. built it but it has a pretty pronounced ticking which bothers me, and the proguitarshop demo video of it doesn't seem to have any ticking. any fixes for that?
    I already tried star grounding but to no avail.

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  20. I experimented with mine a lot today, since the way that it was with the ticking, it was so bad that i'd never use it.

    I finally got the ticking 90-95% quieter and is barely noticeable at all. IMO, it's probably as quiet as the demos of the original posted online now.

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    1. What was wrong with it? Mine had no problems at all, was a smooth build for the first try.

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    2. mine worked on the first try too, but the UJT's ticking really bothered me.

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    3. i am experiencing the same ticking problem. how did you fix it?

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    4. Hi, i have the same problem, no hum, the effect works good but when it's ON there is a continuous and annoying tick. How to fix it?
      I used a MPSA18 instead the 2n5089, with de 2n5089 ticks are more noticeable.
      Thanks

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    5. Hi John, how did you reduce the ticking problem?

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    6. jooooooooohn!!! help us!!! :D

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  22. @John Kallas can you share your experiment...I had a problem with this project, sounds termolo appear without being connected to guitar,like shadow...sorry for my english :)

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  23. https://sites.google.com/site/flofxdiy/deticking-lfo
    i think this site might help.
    i didn't have the time to test the fixes myself yet, but i shall do it soon enough.

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  24. Hey there. I've built this and it works, but i get the feeling that the chopping effect is not that extreme... is there any easy change to improve the chopiness of the effect? Cheers

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  25. from the looks of all these comments it seems that most people are getting dry bleed through on their repeat percussion effects. I built the simplest board of the original repeat percussion and I am definitely not getting that full chop, no dry signal, percussive effect. I was disappointed to find people are having the same problem with this layout. I wouldnt call a repeat percussion with dry bleed through verified. Maybe it just has something to do with these old transistors? anyone order a bunch and fix the problem by swapping transistors?

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  26. I got my build working like I've wanted by lowering the 330k resistor from emiter of the 2446, I've tried diferent values and sticked with 220K witch gave me a lot of chop on the effect! Don't know if this will solve some of the problems here... but it did for me!

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  27. Hi, the demo sounds very nice to me, so I want to build this pedal. I want to add a flashing LED as a speed indicator. But where do i have to add this LED? Do I need a voltage follower to isolate it from the LFO circuit? Could anybody help me with a schematic of this board?

    Thanks :)

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  29. Like Max, I am interested to the flashing led too...does anyone knows how add it?
    Max do you solve?

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  30. Built this tonight. Works great!

    Q1 and Q3 need to be switch on the layout. Mine didn't work at first and it was because I followed the layout and had the 2n2646 in the bottom socket and the 2n5457 in the socket above that. Switch them and it works!

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    1. Aaah I just noticed the numbering at the bottom doesn't match the transistors shown in the layout. I assume your build matches the layout then and ignores the notes?

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    2. right, transistors position is ok for me!
      Also, Mark do you know how I can add a pulsing led on this one?

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    3. When you add a rate LED to a tremolo or similar you need to take the feed for the LED off the LFO. I'm not an familiar with the 2N2646, but it looks as though you'd need to take the feed from B2. Best way to check is to get out your multimeter and measure between each pin and ground to see which one has the rising and falling voltage in sync with the tremolo. Add a current limiting resistor to that pin's row, and feed the LED from that. The CLR value is dependant on how bright you want it, what type of LED you're using etc.

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    4. I did everything as in the layout, all I did was have to swap Q1 and Q3. I saw some of the notes/comments but I figured the layout had been revised by the time I built it.

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    5. I took a multimeter to Q1 and found it was B1 that had the rising and falling voltage. Taking a wire from this row to the LED, I found that it worked as a rate LED albeit very dim even with no current limiting resistor (I'm using waterclear LEDs). Worse than this, I now have ticking even in bypass.

      How would I go about raising the brightness of this LED and stopping the ticking?

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  32. Ok, i`ll try it, thanks ALWAYS for your kindness :)

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  33. Built and sounding great. Thank you for the layouts and all of the info

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  34. question: When in the higher rate speed mode, is there supposed to be a kind of pitter-patter sound to it, almost like a sample and hold?

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  35. when there is not an input hole in the board, the input goes to the footswitch or to the jack in ?

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    1. as per the notes under the layout, input to level 3. input goes to lug 3 of the level pot

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  36. Hi, Having trouble with this build. Bypass works, and when switched on can hear a slight ticking that changes speed with the controls, but no trem or signal.

    To double check, the 2646 goes in the middle of the board, as Q1? Is it possible I got a bad one?

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    1. if it's ticking then IMO, the 2646 is probably working. i'd check for solder bridges or a misplaced component.

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  37. Guys, do you happen to have the schematics for this? Thanks!

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    1. Actually I tried to trace it, could you please doublecheck if it is ok? Thanks!
      http://members.upc.hu/dudas.csaba5/EQD_Hummingbird.jpg

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    2. Sorry missed this before. Just checked it and yes that looks spot on

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    3. Thanks Mark. If anyone interested I made a PCB layout for this one.

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    5. any way you could send me a copy of that schematic?

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  38. Hello Mark, I have no 1uF caps here, could I change for a 0.1uF? Would be a problem? Thanks!

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  40. built this. and start the first time, is very good and sounds really nice, I found some old 2N2646 and everything else brought from TayDa, thanks for these great designs
    greetings from chile
    excuse my English

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  41. Hey...does anyone know how to eliminate the pop-up when engaged?

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  42. try a 1M resistor between level's pot lugs 3 and 1

    ξεναγος νεκρόπολης

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  43. γεια!
    sorry...it was stupid...cause that way you just changed your pots value...sorry again...
    it usually stops with an 1m resistor from input to ground and that resistor isn't somewhere on this layout...that's what i knew and that's why i told you so(or i thought i did...)...maybe from lug 2 to ground?hope you use aligator clips...!!!and don't have to desolder anything...thessaloniki.you?

    ξεναγος νεκρόπολης

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  44. ah!and how did you wired the footswith?did you grounded the LED pole too as this?
    http://tagboardeffects.blogspot.gr/2012/02/offboard-wiring.html

    i always use the offboard wiring from this site and never had a problem.

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    1. Actually I use this wiring but I haven't saw from here in the first place.. Anyway I also thought that maybe the LED causes the sound but when I disconnect it, there is no difference
      I already tried from lug2 to ground with no luck (also from out to ground)
      Τούμπα

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  45. Hi Everyone! I'm a greenhorn in this site, I'm from Hungary, my english is not perfect. I made some circuits from this site, for example this tremolo. I could not find a good Hummingbird schematic, so I drew one, here it is:
    http://tinypic.com/r/b6a6gl/8
    I hope, it's correct, and I hope, I helped someone.
    And, I have some questions:
    1. How can I change the Depth range, because the minimum depth is too much for me?
    2. How can I change the Rate range at Mode 2 (fast rate), because it's too fast? I'd like to make a little overlap between Mode 1 and Mode 2.
    Are these possible? Many thanks.

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    1. i haven't built yet this fx but from your schematic i think you should use a lower value for the 47k(try with a 50k trimmer and go down till your value) for change the depth and you should use a lower/higher value cap(i don't know if mode 2 is the 4,7u or 1u but if it's the 4,7u try a lower, if it's the 1u try a higher) for change the rate. i hope may help you

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  46. Hello,

    After dealing with the damned lfo tick, I've found a way to make it barely noticeable, just in fast mode and very high volumes you'll hear a trace of this upseting noise.

    You have to isolate the ground of the lfo from the rest of the circuit. Make a new cut on the lower row, just under Q3 gate. Now the lfo has no ground connection. Just solder a new wire to the left or right hole of the lover end of the 39r resistor and the other side of the wire to the ground / negative pin of the DC jack.

    This way, the lfo ground is isolated from the rest of the circuit with the 39r resistor, and from the +9v with the diode. You can use a slightly higher value for the 39r resistor, but don't go up too much, 100r maximum.

    J.

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    1. I forgot: you could use too a 10nf capacitor in parallel with the upper 100uf one, this will get rid of the higher frequency noise of the power supply.

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    2. I think you mean "under Q1 gate"... :D

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    3. thanks for the suggestion JaviCAP .. isolating the lfo's ground from input certainly helps cut the tick significantly. i also had to isolate the input jack from the enclosure since it is connected to output jack. SO input jack is gnd to the 3pdt gnd lug which goes direct to DC jack gnd. much quieter but still ticks at high volumes..

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  47. Hey JAVI,
    THanks for the insight. Question(s). Will putting the two caps in parallel get rid of the LFO tick? Or will it only reduce the tick when conjoined with isolating the LFO from ground? Also, anyone have a answer to Ár István's question about changing the depth range? Thanks everyone for the great input. This site rulessssss.

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  48. Seeing as the 2N2646 is hard to get hold of, can I substitute with 2N6027? JayCar website states this is a programmable unijunction transistor so is it right to assume with correct input voltages this could work instead?

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    1. The 2N6027 can do the same thing, but more components would need to be altered so you can't use it as a direct replacement without a new layout completely. If you want something very similar but using 2N6027's then I'd suggest building the Moosapotamus Skippy

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    2. Thanks for the advice. Sounds like I need that transistor then.

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  49. This was a very easy and straight forward build. I like the switch that really spices things up a bit. Thank you for the layout. I have uploaded the images of my build if anyone would like to look.
    http://s1383.photobucket.com/user/denfox1/media/GreenTremolo2_zps5745938b.jpg.html?sort=3&o=1
    http://s1383.photobucket.com/user/denfox1/media/GreenTremolo1_zps3ffe1cd7.jpg.html?sort=3&o=0

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  50. I nearly built this working first time but it was too good to be true. I substituted the 27k resistor in line with the rate pot for a 30k one; Q2 changed to 2N5088; Q3 changed to MPF102. Bypass is loud and clear, the LED is on when the effect is engaged, I hear the tremolo effect and the depth pot changes the depth. However, I am finding the following problems:

    The effect volume is much lower than the bypass volume. Is this symptomatic of another problem or should I replace the level pot with a larger one (100k)?

    The rate pot does not work at all. The tremolo effect at the moment is fixed at a slow rate and a fast rate depending on the switch position. Is this due to my resistor substitution, transistor substitutions or is it another mystery problem?

    Any suggestions most welcome!

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    Replies
    1. Triple, no, quadruple check all your component placement and pinouts and stuff. I found that when building something late at night, that I just completely forgot to add a couple of components to a circuit. It could be something as simple as that.

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    2. Thanks for this. Will check and see if I've omitted something or connected it wrongly. I noticed after posting that Dexxyy on 30 April 2013 had posted using MPF102 and how it made the output below unity, which solves one issue.

      Can I confirm that my substitutions haven't caused the rate pot not to work?

      I didn't mention another issue, though. I pick up radio!

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  51. Can anyone help - i get dry signal through the effect, and the pedal volume pot works fine but there is no effected sound.
    Im confident i have the layout OK, no solder bridges so Im not sure what to check next.
    any advice?

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    1. Maybe you could check the transistors' pinout...

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    2. Did you ever get the effected signal out? I am having the exact same problem, and I am pretty sure the transistor orientation is not the issue.

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    3. I have built 2 variations of these, the original Vox from schematic, and this one as a copy of the vero board, and have the same issue on both
      I am using some different parts I don't know if this is causing my issues,

      I have subbed Q2 for 2n3905, and the diode for a standard 1n4001, the depth Pot for a 50k as I do not have any 25k.

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  52. Just in case my reply about the rate LED got lost up the message board, here it is again:

    I took a multimeter to Q1 and found it was B1 that had the rising and falling voltage. Taking a wire from this row to the LED, I found that it worked as a rate LED albeit very dim even with no current limiting resistor (I'm using waterclear LEDs). Worse than this, I now have ticking even in bypass.

    How would I go about raising the brightness of this LED and stopping the ticking?

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  53. Does anyone else hear a clicking noise when using this at high gain?

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  54. Hey !
    Wondering if it's possible to add a switchable 2nd depth knob (pot in parallel) to potentially cut the trem out of the circuit. Anyone played around with this?

    Thanks,
    Andrew

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    Replies
    1. Easiest way is to use a 3PDT footswitch. Take the Depth wires from the board to the middle row of lugs. The wire a pot to the top row and another to the bottom row. This would give you 2 switched depth settings. Use a 4PDT for an LED

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  55. Hey guys sorry to bother. I've built this twice exactly to the layout and the only thing that seems to be working is the volume pot. There seems like there might be a slight effect but the pots don't seem to do anything. I tried switching the legs on the transistors but still to no avail. Any help would be appreciated. I would hate to just trash it. Thanks in advance!

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    1. Actually the only thing that might be be different is my 100uf electrolytics are 16v. Could that be the problem? They seem to be holding up and not having a problem....

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    2. This layout works - I have built several of these. Take photos of BOTH sides of your board, and post them on the De-bugging page in the Forum.. We can have a look for you and hopefully spot your errors.
      There is no issue with the caps, 16v is fine.

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    3. Awesome thanks Beaker. I removed the 2646 so i'll rebuild and if doesn't work I'll send some photos. Reading the comments I saw some people say they had to switch transistors and all but I assumed this layout was the most recent correct version correct? I probably won't have another built til the Pope leaves town after this weekend, Non-stop work so I'll try and put one up monday. Again thanks!

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    4. Yes, this layout is correct - no doubt about it. The 2N2646 transistors are notoriously flakey, and some just won't work, while others work perfectly.
      It's highly possible that you have an error or short circuit somewhere on your board, hence the request for photos. Don't bother rebuilding it, just post some photos to the debugging thread - you may have made a mistake somewhere.

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  56. Hey peeps has anyone got a schem for this....?? Appreciate it highly
    [might have posted this earlier but it wasn't showing....]

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    1. I know it's a modded Vox Repeater btw....just want to know how modded it is and what the end resulting schem looks like.

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    2. http://effectslayouts.blogspot.com/2015/10/earthquaker-devices-hummingbird.html
      Here it is. dtgehring traced it for us.

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  57. Hi. Would it still work if I swapped the 5457 with a 5458? According to datasheets, they seem reaaally similar. Thank you. :)

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  58. Hi mark, could you help confirm - is the D1 diode supposed to be connected forward bias with the 100R from the 9v and in series with the 470R going to the 100uF cap?
    The schematic from dtgehring looks different on this D1/470R portion.
    Thanks in advance!!

    http://effectslayouts.blogspot.com/2015/10/earthquaker-devices-hummingbird.html

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  59. Sorry, the question was meant for lvlark...

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  60. Built this, effect is work fine. All knobs and switches act how they should.
    However, there is always a pulsing even with no audio connected, and it follows the level when level is at 0 it is still there but gets louder with level increase). and it changes speed with the switch and knob. So theres some noise getting through the effect i guess?

    Any ideas? thanks

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  61. Having built several of these, some ticking is unavoidable - it's just the nature of the beast I'm afraid. Shielded cable on input and output can help a bit. Do not socket the transistor - once you have established the unijunction works ok, either remove the socket and solder to the board, or solder the legs into the socket. Try several unijunction if you have them - some tick louder than others. Finally, make sure you have nothing, including the lid of the enclosure touching the unijunction - it needs some fresh air around it. Try pinching it between your finger and thumb aand the ticking gets louder!
    I hope this helps.

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  62. I dont have a 1u ceramic cap, what is a suitable replacement for it? I have tried with Tantalum 1u but I am getting no effect, just try signal that is affected by the volume control.

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  63. will the "2n2646 manu: on encapulation: can-3 unijunction transistor work with this? they're fairly cheap on ebay. or are they different

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  64. This one worked great for me.

    I had a LOUD ticking noise from the LFO for a while, but after a bit of tinkering it went away. I guess there was a loose connection somewhere; I didn't change any components. Now it's pretty quiet even though the connections are still going through the breadboard.

    I used 2n2222A for Q2. MPSA18 also works, but I ended up preferring the other one.

    I used an electrolytic for the 1uF, as it was all I had. It works both ways round but the sound seems a bit stronger with the anode on the emitter of Q1.

    I used 100k for Depth, again all I had handy. This allows you to roll the depth right off and use the pedal as a (very nice) transparent boost.

    Finally, I've currently got the Rate pot replaced with an expression pedal. I've wired up the 3 lugs of a stereo jack socket in place of the pot's lugs (some trial and error with croc clips needed). Then a TRS insert cable from there into the in & out of a cheapo volume pedal. It works backwards (i.e. heel down is high, toe down is low) but I can live with that.

    Thanks for this superb site -- I have a long list of things to build next...

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