Here's a cool variation of the Vox Repeat Percussion tremolo from EQD. It adds some extra controls to the original circuit for more versatility and control. I had a hard time tracking down a schematic for this one and ended up just tracing the vero layout from the Tagboard Effects blog. So here you go internet, the schem for the Hummingbird:
This is a library of perfboard and single-sided PCB effect layouts for guitar and bass. I'm not an electrical engineer by any stretch of the imagination, just a DIY'er who likes drawing layouts. It is meant for the hobbyist (so commercial use of any of these layout is not allowed without permission) and as a way to give back to the online DIY community.
Where can i find em-drive?
ReplyDeleteUse the search bar. It was back in Sept.
DeleteHey :) for some reason when I try to search 'hummingbird' using the search bar it gives me no results! Weird. Just thought I'd letcha know.
DeleteHi. Would it still work if I swapped the 5457 with a 5458? I'ts difficult to get a 5457 here and I found some posts that say they're similar. Datasheets say that too. I'll appreciate any opinion anyone has. Thanks. :)
ReplyDeleteI think a 5458 would work just fine. You could also try a J201. Sockets are your friends ;)
DeleteThanks man! I should've bought that 5458 when I had the chance. When I do, I'll do my best to verify this layout. :) Cheers.
DeleteI think you can call this one verified.
ReplyDeleteIt's working as far as I can tell. But it's popping like crazy.
I had the same problem with others layouts of this pedal.
Any ideas on how to make the popping noise subtler will be appreciated.
Will shielded wires help?
Thank you very much for all the effort and the layout guys. This is a great site.
Is it popping with the rate of the effect or just when you turn it on/off with a switch?
DeleteSorry. Wrong word.
ReplyDeleteIt is ''ticking'', with same rate as the LFO.
I don't think you're alone with the problem when cloning the Hummingbird. Lots of people had similar issues over on the Tagboard blog. First fix to try is upping the value of the power filter cap (second 100µF cap from the left) to 220µF or higher. You may also want to run the power through a 100-200Ω resistor before it hits the board.
DeleteHi! First of all thank you for all the effort you put on the site.
ReplyDeleteRegarding the hummingbird, is it possible to have a rate-indicator led instead of the classic fixed one?
Should i have to take the led + (or - ?) wire from somewhere around transistors?
Thank you again for your site :D
Someone asked the same question over on Tagboard and lvlark had this advise:
DeleteWhen 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.
Super-cool!
DeleteI'm absolutely tryin' it in the future!
Thank you :D
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Deleteyou need to add the LED in parallel with R11 :-)
DeleteI have build this layout 2 times. The second time I used the BC549C instead of the 2N5089 and the 2SK168 instead of the 2N5457. It worked without any problems. Also instead of 25kohm pot for the depth I used a 50kohm pot. So apparently the layout can work with alternative transistors and pot values.
ReplyDeleteAny change in the depth pot?
DeleteI used b100k for speed, and b100k on input.
DeleteWork great
What about to use SPDT on/off/on in mode switch?
ReplyDeleteWill work without any cap (middle/"off" position)?
You could try it, but those are some pretty high value caps being switched between. It's likely that no cap to ground there will result in some weird speeds.
DeleteSure.. I'll give it a try.
DeleteAs I notice in the "mode 3" in the latest EQD version, it's in the middle position: an ultra super percutive speed.
what happended whn you try the no cap position??
Deleteit turns off the lfo... no extrem high speed or weird stuff here :,( but it makes a clean boost with the volume input cranked a little !
DeleteGreat tremolo... the best one IMHO.
ReplyDeleteHow can I add an rate indicator LED? Is that possible?
Found it: you need to add the LED in parallel with R11.... and voilà!
DeleteHi, great info! Does your led flash in bypass? If don't, how do you achieve that? I can't figure it out :S
DeleteAny alternative to 2N2646?
ReplyDeleteNot without redesigning that portion of the circuit. :\
DeleteTest the circuit first on breadboard its working as it should. Build it on perfboard.
ReplyDeleteonly the level control works, it act like a clean boost when pedal was engaged. Any idea? Thanks
Short answer: You built it wrong. :D
DeleteLong answer: Check your connections around the Depth pot and R4 on the schematic (and really anything in the LFO).
Do you think my 2n2646 is still ok? That's the LFO right? I'll see it again to check the depth pot and r4 as you suggest. Thanks
DeleteYeah, definitely check around the 2646 too. Those are old devices and I don't know how reliable they are. I've only built one thing with 2646, so I don't have much experience with it.
DeleteI've run check on the circuit again checked for possible mistake...I've heard the ticking. The ticking changed when I turned all the knobs and switch, in that way I'm thinking 2n2646 is still functional together with the knobs and switches...so the problem narrows down with other parts and solder sides. The ticking almost gone in lower level so not much a bother to me..but still just clean sound no tremolo. By the way I solder 2n2646 direct to the board no socket only 2n5457 an 5089 are socketed. Just worried that I might fried it when I try to resolder and solder again. Maybe I should socket it too...thanks will post you an update once I get this thing done...
DeleteDid you fry it? Mine stopped working so I'm thinking I've done the same
DeleteGreat job! Does the Level pot increase the gain of the circuit as it is turned clockwise? I mean the light overdrive that you can hear with the Depth pot all the way up.
ReplyDeleteI've built a Vox Repeat Percussion based on another layout with a similar Level pot and its behaviour is this: as you turn it clockwise you get more volume (as expected), but you get more gain as well. I think this effect sounds great with a little bit of this overdrive. I like to set this kind of effects at the same volume as the guitar but if I do that with my build I don't get this light overdrive I said before, at least at unity gain. What I get at unity gain it's not as much overdrive as I would like.
So, is there anyway to control gain and volume in a separately way? As in every OD, fuzz or distortion pedal. I'm not an expert but I'm enjoyining a lot! :)
It's not designed to give overdrive. The level pot is there to help set the volume of the signal coming into the circuit, and probably to keep the circuit from distorting. Easiest way to add drive is to push this pedal with an overdrive pedal. But you could also play with the values of R5, R6, and C4.
DeleteYou're right about putting it in front of an overdrive pedal, but if I can avoid it by getting more gain with the hints that you gave, so much better. I think I will try with some trimpots for R5-R6 and see what happens. I will tell you how it went.
DeleteThanks!
Hi, what's about a 2n6027 instead of 2n2646, would it make any major difference? thanks
ReplyDeleteIt shouldn't. But you'll need to modify things a little to get it to work with the 6027. See the more recent Skippy layout for more info.
DeleteCan I use 2N6027 instead of 2N2646 as in Skippy Tremolo? Thanks
ReplyDeleteNot with out modification. Compare the two schematics
DeleteHi,
ReplyDeleteIt works for me ! But I've some questions. When I play with a clean sound, I hear that the sound saturates with no particular position with the volume, do you have an idea of what could do this? I was also wondering why there's no cap between the input and first pot to avoid noise ?
Reduced the ticking to acceptable levels by wiring the 39r resistor and switch lug 2 to dc jack ground instead of the circuit ground
ReplyDeleteRate led is wired led+ and 3k resistor to rate 3, led- to B2
Hi! Any ideas how to wire the control pedal input as in the original?
ReplyDeleteHi there, I built this effect and it seems to work but the it is sucking volume even with the ”level” all the way up. I don't have 2n5089 but I tryed 2n5088, bc550, mpsa18 instead, all with the same results. Maybe my 2n2646 is a little bit different and I need to tweak the circuit to make it louder? Any ideas of what could go wrong or how to get more volume out of it? Thank you so much!
ReplyDeletep.s it works the same no matter of the position of 2n5088, 'e b c' or 'c b e'
ReplyDeleteCrappy 2n5457, I spent the whole day rewiring my entire circuit because of these shitty transistors. I put a j201 and now it even givse me a sight overdrive with 'level' all the way up, loooooads of volume..... never knew these 5457 have such problems, they need biasing I think. If somebody will have volume issues with this pedal, check that freacking 2n5457..
DeleteGlad you got it sorted. Through hole JFETs are a bit dodgy these days sadly.
DeleteYeah, I've ended up replacing the 22k with the 122k to get the approximately 4.5V at the 5457's drain leg. Now I have more than enough volume. Thank you for the layout!
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ReplyDeleteObsevo que en tagboard effects hay dos resistencias de 100k que aqui no se encuentran... son necesarias? Tambien, todavia lucho con el tic presente del lfo... alguna otra alternativa a la ya mencionada?
ReplyDeleteMi circuito maracaba el tic del lfo. Cambié los transistores bc549c por los 2n5088, y desapareció.
DeleteHi there, I've just finished building this pedal. I've had some successful and unsuccessful builds before, most of the times that I got that ticking problem it was either because of bad potentiometers or because they didn't have good connections to the pcb.
ReplyDeleteNow I've got a different and rather unexpected problem, the pedal gets radio frequencies when I touch the potentiometers or its enclosure. Basically anything that is connected to ground.
Although all the cables, amplifiers and instruments here are in perfect conditions, if I turn this pedal on it gets this interference.
Would someone have any tip to help me? Thanks in advance.
Tu conseguiu resolver? To querendo montar esse layout copiado e colado sem colocar nada equivalente.
DeleteNão consegui descobrir o problema. É engraçado que a primeira vez que montei ele, o circuito funcionou perfeitamente, mas tive problema em todas as outras vezes que montei.
DeleteHi! I tried this with a 2N6027 instead of a 2N2646 (found the "mod" and was very easy to do. also implemented a pulsating led for the rate) But now I have a problem with rate and the depth. They only work when they are fully CW. I've done some debugging but can't figure it out. Any advice?
ReplyDeleteCheck your potentiometers. Maybe they've stopped working while soldering. Try replacing them or test them with a multimeter.
Deletehelp...
ReplyDeleteI follow the layout using 2n2646, 2n5457, 2n5089. And it comes no effect, just a radio...... Can anyone help me troubleshooting this?
I had this issue at first, in my case it was the orientation of the 2N2646 and the 2N5457 as they're different from your regular BJT transistor.
Deleteahah thank you, i put those two on a switch so you can play with weird white noise when you want :D
DeleteThis thing works fantastic if you use 4.7 uf caps instead of 47uf, and play use humbuckers. Loads of volume on tap. Didn't respond well to my tele.
ReplyDeleteHey folks, is there supposed to be some overdrive in the resultant sound? I can't get my build to sound clean....
ReplyDeleteIf I reduce the volume on the guitar, or level pot, it cleans up, but you loose a lot of bass, and with 2 pickups on it's not very workable at all.... I noticed this overdrive as soon as I built the first section with the JFET 5457.....
Anyone else have a similar issue? also surprised that there's about 8v on Q1 after R5.
I located some J201's and that addressed the saturation/gain issue.
DeleteI suspect that this schematic isn't biasing the 2N5457's correctly as LTSpice shows saturation too.
i built this using the etch template and I can't get the depth pot to have any effect. I have tested the pot and its fine. Tried using a 100k pot. I am getting 0.4v on the base of the 5089 and 0v on the collector and emitter. I've verified all resistors and caps are correct values. Any advice on where to go from here?
ReplyDeleteBit more info. I built a version on strip board and used the same transistors. It worked without issue. Very strange. I did use a large greencap for C2. I'm stumped.
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DeleteHola, estoy teniendo problemas con este proyecto, se escucha el tic del lfo pero no tengo señal de audio. Estoy usan 2n5088, 2n4548 y mu20 en reemplazo del 2n2646. Alguna sugerencia?
ReplyDelete