Tweakers may want to add a Chorus/Vibe switch, and if so you can do this by switching out the 10K resistor directly to the left of IC3.
Video of Geiri's build of this layout:
Original version
Modded version with Chorus/Vibe switch
Modded version with Chorus/Vibe switch and 3 speed Mode switch
I'm gonna start working on this one - I love the sound of this thing - Thank You!
ReplyDeleteYou could have done it a week before :P
ReplyDeleteWe like to play hard to get sometimes! :o)
DeleteSo that's why it's called 'zombie chorus'! I've never heard any sound clips of this before! I'm not normally a fan of Chorus, but I quite like this though!
ReplyDeleteYes it seems quite extreme, that's why I think the Vibe switch is a worth while mod.
DeleteOK, I just fired it up and it's working - nice lush chorus and no ticking! I didn't do the Vibe switch mod but I'm tempted - will this mod alter the chorus sound? Thanks for the nice layout!
ReplyDeleteNow that was fast! Thanks for verifying Frank!
Delete+m
Nice one Frank. In answer to your question, no it won't affect the chorus sound. The chorus effect is just the dry signal mixed in with a modulated signal, whereas the vibe effect is modulated signal only. So the 10K resistor passes the dry signal into the mix just before the output, so if you switch that you are just essentially turning the dry portion on or off.
DeleteThanks for the explanation Mark - I know what I'll be doing tomorrow!
DeleteGreat, looking forward to hearing how it turns out
DeleteVersion with Chorus/Vibe switch mod added
ReplyDeleteIs it possible to have a LED blinking in tempo?
ReplyDeleteI was thinking about that before. You'd need to take a feed from pin 7 of IC4 (or daisy chained off the Rate 3 lug, and I suspect you will still need a resistor of some sort to limit the current. That's where you will want to experiment anyway.
DeleteI just added the vibe mod switch and that works nicely - it got me to searching for other possible mods, and I came across a mod that Mark Hammer used on his. Here's what he said:
ReplyDelete"My Zombie has a 3-way mode switch on it. Two modes are stock, and the third uses a smaller value cap (330pf or so, I think) to bump the clock frequency into the range normally shared by some flangers when attempting to mimic slow Leslies. So, just a hint of comb filtering. Sounds nice. Reminded me of "Badge" when I first heard it."
I'd like to add this mod also but I can't find any more info on how to do this - any help would be appreciated.
Thanks Mark!
Sounds cool, you should do it and report back how it sounds.
DeleteI suspect it will be one of the 1nF caps attached to the Mode switch, but I'm not sure which one. I'll see if I can find more info.
DeleteLooking at the datasheet for the CD4046 it looks like the 330pF will have to go in between pins 6 and 7 instead of the two 1nF networks that combine in conjunction with the mode switch. I'll have to have a think about the best way to add it with the minimum amount of changes to the stock circuit.
DeleteRight I messed something up first time so to start again.
DeleteRight I've added a new modded version with a 3 speed Mode switch added. Just to explain it, the caps go between pins 6 and 7 of the CD4046, so you always have the (moved) 1nF cap on the board in circuit.
The M Sw wires share holes with the middle 500pF cap on the switch. In the middle position the middle 500pF cap is put in series with the 1nF cap on the board giving you 333pF and the slowest speed setting. In the down position the two 500pF caps on the switch are combined in parallel to give you 1nF, and then put in series with the 1nF board cap to give you 500pF which is the middle setting. In the up position all the switch caps are bypassed leaving only the 1nF board cap in circuit giving you the fastest setting.
The speeds are out of order but it's about as close as you can get using a common 3 position toggle DPDT switch.
Vibe switch is interesting. I think that in Sabro's vero is the R5 the one to replace if I'm not wrong. Will try it this weekend (and if so, i'll get rid of a standing resistor :p)
ReplyDeleteBR
Just checked it and yes it's R5 mate
DeleteThanks again, dude :P
DeleteWow, I can't thank you enough for posting these mods! I'm gonna see what I can do with that 3 speed mode mod, but it'll have to wait till tomorrow. Not enough hours in the day!
ReplyDeleteThere you go Frank try that one, it should be easier to adapt.
DeleteUpdate for Frank
I didn't change the type for the mode switch in the notes but it's a DPDT on/off/on
Oooops - I already made the adjustments on my original build - it's a complete Frankenstein board now, but it's working as are all the mods. The only problem now is, it is ticking. I don't know if that's due to me moving all the parts around, fixing original trace cuts and adding the new cuts and links etc. I'm gonna try a new build when my order of veroboard arrives - I had to join two pieces together on my first build because I didn't have a big enough piece, but I want to try this again with one board!
DeleteI really want to thank you for all the time and effort that you put into this, and all the other layouts! SUPERB!!!
Also, I found this diagram to stop LFO ticking:
Deletehttp://tinyurl.com/c66864h
The gentleman who posted this recommended a 1000uf cap but he used two 470uf caps in parallel because he didn't have the 1000uf cap.
Do you think this will help with the Zombie Chorus ticking?
And in the above LFO De-Tick layout, there is a trace cut beneath D1 - but D1 is optional anyway.
DeleteIn all honesty, if a 470uf cap doesn't do it, then a 1000uF won't either. I don't think it's noise from the power supply, it's LFO noise. It would probably be better to increase both 10u vbias filter caps, particularly the one attached to the LFO rather than the main filter cap. It could be something as simple as a wire that has moved close to a sensitive source during your mods. We know the effect CAN be silent because it used to be, so something has altered which has introduced the ticking and that points to interference from a wire somewhere. Just try moving them about a bit to see if the intensity of the ticking changes?
DeleteI just want to give you an update on my second Zombie build using your layout with all the mods - everything is working and no ticking with this one! Thanks for the layout, mods and help - I really appreciate it!!!
DeleteGreat, thanks for reporting back Frank
DeleteWhat needs to be done to make this bass compatible? :)
ReplyDeleteThere isn't that much to change to be honest. Most of the components are dealing with the LFO, clock and BBD and they wouldn't change so really you're just looking at maybe increasing the caps in series with the signal path to make sure all bass frequencies are getting through.
DeleteThe most obvious cap that may need changing is the 1nF input cap which to me looked small even for guitar (although it's obviously not by the demos). The output cap at 1u looks ok for bass. Apart from that there are a couple of low pass filters but they'll let all the bass frequencies through anyway.
So I'd say socket the input cap and see what difference that makes with bass, apart from that everything else would appear to be compatible.
Mark,
DeleteThanks a ton mate. Great job overall. Keep it up!
I bought these MN3007's and they worked fine for me. I suppose it'a decent price
ReplyDeletehttp://cgi.ebay.co.uk/ws/eBayISAPI.dll?ViewItem&item=111001427868
Ha ha, that's good to know, I bought 20 off them yesterday! :)
DeleteI have a question on this pedal.
ReplyDeleteWill this pedal create the same sounds as a EH Small Clone / Analog man Chorus with a switch to get it sounding like a Roland (boss) CE-2 ???
I need a good chorus and am interested in this build, or tonepad's Small Clone clone
lol
anyone?
Try the Small Clone clone (or original, I've seen used units for about 30 euros).
DeleteZombie Chorus is not an incredible chorus, nor near a top one. Sounds really good, but if you're thinking about a CE-2, forget about it.
Samll Clone emulation is better, but not verbatim. It's a good chorus, a nice and project, but has its own personality, if you're looking for a SC or a CE-2, go fot them.
BR
Ah ok, I will just go for the Small clone clone then... I really don't care for the CE-2 tones and like the Kurt Cobain warble that you get from a small clone!
Deletethanks!
That surprises me Javi, I've got a Small Clone and it's lack of controls make it a bit of a one trick wonder. I thought the Zombie would have been preferable actually, especially as the important components are pretty much the same or comparable, it's just the clock method that differs.
Delete
DeleteMark, the Zombie in clone mode is able to sound similar to the SC, but sounds just "similar". If you just play with the Rate Knob, and forget about the depth, you can get some spots where the sound is nearly verbatim, but that's all. The Zombie has not all the sounds of the Small Clone, and what's more interesting, the Small clone has not by far all the sounds of the Zombie.
To my taste, the Zombie is much more preferable and versatile but won't consider it a Small Clon substitute, as I stated previously, has its own personality.
Haven't checked the SC circuit (I'd never consider cloning a comercial modern pedal that I can get in nearly mint state for 30 euros), but have red in some webs that the zombie lacks many components that are present in the CE and the SC.
That's why I recommended to Leo that if what he wants is the SC sound, go and get one (cheap and good sounding), because if he builds the Zombie, may love it o may find that he gets not the sound that he wants.
By the way, I absoultely recommend building the Zombie if you want to try a versatile and fun Chorus, but woulnd't do it if what you want is a Small Clone.
BR
The Zombie, Small Clone and CE2 are all very similar indeed. Opamp inputs and outputs with the BBD in between. Clock linked to the BBD (CE2 uses MN3101, SC uses CD4047 and the Zombie uses the CD4046) and all with dual opamp LFOs.
DeleteThe main difference is that the Small Clone and CE2 has (I think) 4th order filters followed by a buffer at the input and output of the BBD, so there is a bit more component tone shaping to the modulation.
This comment has been removed by the author.
DeleteWell, I installed the vibe switch some minutes ago, as was waiting to some CD4046 that i ordered a few days ago (I used the 74HC4046, that seems to be direct replace).
DeleteVibe switch: yeah, it's a nice adiction to the Zombie, like the extra versatility it offers to the effect.
CD4046 was socked when I could hear..... tickin'! Didi install the 74HC4046 again, and problem gone. I've been taking a look to both datasheets and all I could understand is that these ICs are not exactly the same, so not a full replacement.
Can¡t really find differences in tone using both, just the tick tick problem!
No need to tell that the original 74HC4046 has returned to the socket. Will have to comment this issue with Harald.
BR
If you have ticking problems, try placing a buffer or a booster in front of the zombie. I got a MXR Microamp, and when it´s on, the ticking disappears completely
ReplyDeleteJust an observation from me when building my second Zombie Chorus. If you're getting a dry signal coming through but no chorus effect, then you've most likely got a faulty MN3007. I bought 10 of them and 3 didn't work. I recommend testing all the ones you've got and bin the faulty ones.
ReplyDeleteI've also built the Little Angel chorus but this thing is just SO MUCH BETTER. It's worth it and it's not really hard to put it in a 1590B anyways.
Just wanted to reinforce this -- I tried a lot of phoney MN3007s (from China and the UK) with no luck. At best I was getting dry signal only, and sometimes the chip went up in smoke.
DeleteOne very expensive order to Smallbear got me the real deal. I usually wouldn't spend so much on a component but this effect is well worth it IMHO.
Hi guys,
ReplyDeleteI finished the pedal and works really good, however I noticed that the signal saturates if I use the humbuckers instead of the single coils of my guitar, is that normal?
Any suggestions?
Modulation pedals can often clip with a hotter signal, I had a Jacques Meistersinger which was fantastic but suffered from the same issue when I was using my Les Paul.
DeleteI'll see if I can find a mod to tame it a bit when using humbuckers.
Thanks very much for the explanation Mark, I'll stay tuned!
DeleteHi,
Deletejumper the 47K next to the mode switch terminals with a bare wire and remove the 100K that is connected to the 47K. Found this information in a german forum, works fine for me;-). Blinking LED feed from rate lug 3 doesn´t work btw...
Heiko
Hi Heiko,
DeleteThanks for the mod!, the pedal works a lot better now, however, in the bridge humbucker still a bit of saturation but a lot acceptable than before.
Any op amp swaps for the tl062?
ReplyDeleteI've built a few using TL072, works fine!
DeleteYou could try any common dual opamp, but the TL062 is particularly good in LFOs which is why I suggested it here instead of the NE5532 shown in the schematic. It's the low power version of the TL072 and many people have commented that LFO ticking that you can hear with some opamps is reduced or eliminated by using the TL062.
DeleteFair enough, I'll try everything I have and see which works! haha.
DeleteBuilding my 2nd zombie
ReplyDeleteThis one with the 2pdt mode switch
I don't have any 500 pf caps, I have 470 and 560, which would be better
Also does the led+ off the board do away with the need for a 3pdt switch to control the led
Thanks
Ed
Built it, worked fine first try, thanks a lot again for a beautiful project. Really nice sounding chorus, I find it better and more versatile than my Small Clone clone (even with the depth pot mod). My only concern with this one is the depth range. For me could be a bit more. Is there a way to extend it?
ReplyDeletemmm, somthing wrong, any idea about compatibily of hef4046bp?
ReplyDeleteThis comment has been removed by the author.
ReplyDeleteDone! well, I had a chance to directly compare it to my tonepad Boss CE-2 build today and the CE-2 is 10X better, but the zombie isn't bad at all. IMO, the zombie is a lot better than the Little Angel.
ReplyDeleteZombie pic:
http://johnkvintageguitars.homestead.com/Effects/others/Zombie-01.jpg
Tonepad CE-2:
http://johnkvintageguitars.homestead.com/Effects/others/CE-2-01.jpg
Nicely done John, thanks for the pic
DeleteHi Mark, where would I connect the negative side of the LED? Thanks in advance.
ReplyDeletea mi me gustaria tambien saber.....negative led....help
Deletethe cd4046 must be unbufferet?
ReplyDeleteSomething wrong and dont found, my cd4046be dont works?
Hi,
ReplyDeleteHave any of you guys experienced high pitch noise when mode sw is in off mode and vibe sw is on?
I have that problem, can someone provide some solution or why does that happens?
Also my pedal is too noisy...it is humming loudly...on battery not on ps. how to fix that? I use tl72 ics.
i do have chorus effect it is very very nice but pedal is not working all the way as it should, please can someone help me on this one?
Thanks,
tick tick tick ughhhh
ReplyDeletemine doesn't tick, but after building a Boss CE-2, IMO, the Zombie is a bit disappointing.
DeleteI just printed off the Boss. I did notice that the ticking isn't as prominent after swapping the 10uf cap for a 22uf.
DeleteThanks Ivlark this was a great build. Spent my time and got it right first time and is sounding great.
ReplyDeletehi all.
ReplyDeletehappy new merry year holiday xmas -can't spell hanika.
is a CD4046BE ok to use here. The pix show CD4046 (no suffix). I cannot find a data sheet for CD4046 (no suffix) they are all BE UBE etc...I think BE is 'buffered'...anyway will CD4046BE work?
here's my build (alcohol-driven angle!) of the Zombie Chorus, w/vibe &3pos mode switch.
ReplyDeletehttp://imageshack.us/a/img19/5792/eey1.jpg
i quite like it, but it's definitely noisy (less noisy with switch in the middle position)
What kind of noise? Hum, hiss? I built this a while back and mine is very quiet. Now, I will say that I haven't played it at stage volume but I've had it at mid volume level and never noticed any noise. Have you tried a different power supply? I use a 1Spot and have never had any noise issues from power supplies. But I have read back on different threads where noise issues were improved or eliminated with different/better regulated power supplies. Just a thought.
ReplyDeleteI do like this chorus. I hadn't played it for several months and plugged it in during the holidays when I had more spare time. You can cover a lot of sonic ground with the mode and vibe switches. Knocked my Boss Chorus ensemble off the board ( I had used the chorus ensemble for the last 15 years or so...).
If the banished CE is a CE2, I'm more than willing to offer a new home to this little pedal:P
Deletehere's a soundclip i've recorded with bass, so you can judge by yourself:
Deletehttp://clients.cylens.net:8117/diy/zombi_chorus_vibe.mp3
same when powering with a brand new battery and swapping ICs...
Javi
DeleteAfraid it's just a normal CE5 - really does a great stereo sound though with 2 amps. Sabro's got a verified CE2 layout though. I think you need to build it and squeeze it into an A enclosure ;). http://www.sabrotone.com/?attachment_id=3738
cylens - it seemed pretty quiet ( except for the switch popping ) up until about 2:44. Then I hear the hiss. Wonder if that setting that you change to there has a little more gain on the circuit. I'm not technically able to ascertain that with my knowledge level though. Nice tone and playing btw....adds a nice swampy texture to your already nice tone.
around 2:00 I put it in "vibe" mode, si I guess the noise coming from the delayed signal is more exposed (not mixed with dry signal).
Deletedon't get me wrong, i'm not complaining and will definitely use it, but to me, this is not "clean": the bass goes straight in the audio interface so it clearly exhibits the characteristics of the pedal (i wouldn't say "flaws"). should i have plugged it in an amp, I might not have bothered... thanks for the kind words!
I'm quite new to veroboards, but there seems something strange with the layout:
ReplyDeletewhat's the polarity of the 1uf cap (between output and VSw5)
It could be my stupidity of course
I'm quite new to veroboards, but there seems something strange with the layout:
ReplyDeletewhat's the polarity of the 1uf cap (between output and VSw5)
It could be my stupidity of course
It shows a polyester capacitor which don't have polarity
DeleteAh ok, didn't know that existed even. Is there an audible difference in between the polyester cap and the electrolytic for 1uf?
ReplyDeleteIs there also a possibility to make requests for certain effects?
Thanks for the fast answer and the great job being done here!
Cheers
I built this 2 weeks ago and still can't get it going...I have tried everything. I even cut and repopulated a new board. I'm getting nothing but dry out of it.Tried 4 different MN3007, 3 separate CD4046, and 2 sets of TL072 chips. I've checked all cap polarity's and triple checked all ohm values. All jumpers and cuts are correct and i still can't get it going. Any one have working voltages on the ICs? Please help?!
ReplyDeleteOddly enough, I too am having the exact some problems. Unfortunately, the MN is 10.00 and I'm not real happy about dropping 50 or 60 bucks just to get one to work.
DeleteI know - the bay has them cheaper I'm sure, I really prefer not to go that route. So - I'm shelving this one as I did with the 2 builds of the Angel chorus. I guess modulating devices are just not my types of builds *sigh*
You may prefer not to get them from eBay but sure it makes more sense to put the board to one side for a while, get some and then see how you get on when they arrive. I've bought a few of these and they work fine, at that sort of price it's a no brainer when the alternative is ditching the board http://www.ebay.com/itm/271376214280
DeleteHi everyone,
ReplyDeleteI just finished this layout (with vibe switch and 3 speed switch) and have (too) many problems.
First, I only have dry signal. I tried another MN3007 but it sounds exactly the same.
So 3 speed switch logically doesn't make any difference.
Though, I can hear a ticking noise.
And a last problem with the vibe switch: I only have signal in one of its two modes, when 10k resistor is on.
Any help, please?
I forgot to say I tried other dual opamps. Same result. :-(
DeleteWhen the 10K resistor is in circuit, it passes the dry signal and so you get a chorus effect with dry signal and modulating signal mixed in with it. In Vibe mode the 10K resistor breaks the dry signal and so you only get the modulating effect, hence a vibe. So if you're only getting sound when in chorus mode it sounds like you're just getting dry signal and you're not getting the modulation from the MN3007.
DeleteYou're getting ticking so the oscillator is working (although the speed switch should change the rate of the ticking). So to me it sounds like the MN3007 or some of the connections to it. Are you sure they are ok? There are a lot of fakes out there for MN series ICs and you may have a entire bad batch.
If you do know the MN3007 is good, then check the pin voltages to see if that throws up any clues.
Thanks for your help and your explanations, Mark!
DeleteI'm not really sure my 2 MN3007 are good: they are the 2 first I have, so I can't put them in another build to verify they work.
And even if I bought them on a renowned site (not ebay...), I don't know if each IC is checked by the seller.
So I checked the pin voltages.
For a DC input of 9,71v (AC adapter):
Pin 1: 9,71v
Pin 2: 4,71v
Pin 3: 0,10v
Pin 4: 0v
Pin 5: 0v
Pin 6: 4,80v
Pin 7: 4,90v
Pin 8: 4,90v
What can you tell me about these results?
Thanks again! ;-)
Mine is working with these voltages:
DeleteBattery at ~9,2V
1: 9,0
2: 4,48
3: 4,90
4: 0
5: 0
6: 4,5
7: 4,97
8: 4,97
Your measurements seem to be in the ballpark, so i think you're problem must be somewhere else than with the 3007.
I do find this to be ok chorus, but it has real difficulty taking hot humbuckers in without adding distortion. Should probably try to lower the mixer gain at some point. Works ok with singles.
+m
Hey
DeleteIve got the same issue. Did you manage to figure it out?
Hi Mirosol and thanks for sharing your voltages!
ReplyDeleteThe only difference I can see when I compare them to mine is about pin 3: my voltage is weak for the least. Does it mean that signal doesn't come to 3007?
Hi everyone!
DeleteGood news: my Zombie Chorus works like a charm!
My problem was a faulty socket on IC1...
And there's no ticking anymore. Great!
Thanks to Mark for this great layout (again) and your help with Mirosol!
I think i have a crude workaround for the distortion. I soldered 4K7 in parallel with the 47K from IC3 pin 2 to IC1 pin 3. At least it tamed most of the distortion while keeping the level up. I think this sounds even slightly softer now. If not softer, then slightly less harsh. It still distorts when i hit chords hard, but not nearly as much as before.
ReplyDeleteSo if someone else is experiencing the same issue (distortion with good humbuckers), just lower the value of that one resistor.
+m
Just finished up my 2 nd zombie
ReplyDeleteGave the first to my son
This one sounds nice and clean with no ticking
However the depth knob O's not functioning
The chorus seems fixed at about 50 %
Any suggestions on de bugging this
Thanks
Ed
Check the voltages of IC2 and IC4 and let us know what you get
Deletei just built this but it real tame..doesnt wobble like the demo video nor does it really sound like a chorus. any idea what could be wrong?
ReplyDeleteIs the MN3207 a substitute for the MN3007? Specs seems to be the same and it's much cheaper.
ReplyDeleteThey do the same thing but you cannot replace one for the other in a circuit without modification, so no you'll need to use the MN3007 in this.
Deletehmm... Okay thanks Mark.
ReplyDeleteI will check on Ebay for more friendly priced ones. Inet shop here sells them for 12 euros each.
I confirm, if it doesn't work, try many MN3007...I've bought 5 of these on ebay, 3 doesn't work, 2 works but maybe not very very well I think............
ReplyDeleteThese are cheap enough to buy in a few and I know at least some are good because I've had them before and so has Javi I think
ReplyDeletehttp://www.ebay.com/itm/271376214280
Ig I'm not wrong, these are the ones I purchased time ago:
ReplyDeletehttp://www.ebay.es/itm/2pcs-Panasonic-MN3007-Audio-AMP-Delay-Effect-IC-m-/170690231721?pt=AU_B_I_Electrical_Test_Equipment&hash=item27bdee3da9
No problem so far, al I've used, worked great. Anyway, when I need a genuine IC beyond any doubt, I purchase it at Retroamplis, a spanish based store, but prices are not exactly cheap :P
http://www.retroamplis.com/epages/62070367.sf/es_ES/?ObjectID=3582809&ViewAction=ViewProduct
J.
That's still a great price if you know they are guaranteed to be original and working well.
DeleteHere's one for you mate
Deletehttp://www.retroamplis.com/epages/62070367.sf/es_ES/?ObjectPath=/Shops/62070367/Products/%22TR-MATCH/2N5952-4%22
:o)
Hehehehehehhe, I didi see this quad, but as I wanted too some vactrols, I did purchase both quad and vactrols at Musikding. Optos were way cheaper.
DeleteHave to build still the Phase 90, is still on my to do list :P
I bought my MN3007's from BanzaiMusic and got my Zombie walking :)
DeleteFirstly I tried a couple of 3007's bought from eBay, but they seemed to be bogus. I had clean signal coming through but no effect of any kind.
I bought two 3007's from BM and to my relief, they actually worked! And I must say, this pedal is a gem! Worth every penny and hours of troubleshooting :)
Thanks, Mark!
Hi, I have the same problem as other builder...My build makes a siren noise in one of the modes, If I place the Zombie behind something else, tuner or compressor the sound vanishes, also if I cut the tone of my bass... any ideas about this?
ReplyDeleteI just finished building the vib mod version of this layout. Overall it is working fine.
ReplyDeleteHowever I have a weird ticking problem. When I test the effect with my bass, an
Ibanez active bass, everything works fine. However, when I used it my guitar, a Cort
statocaster look-alike, i get ticking even if the effect is bypassed. I sued the following wiring scheme for the 3PDT foot-switch:
http://www.singlecoil.com/tb-strip/dia1.html
Is there anything I could try to solve this issue?
P.S. I made the ground connection of the jacks and the foot-switch from the board instead of from the DC jack, could this have an effect on the ticking?
thanks a lot.
i have a problem with mine, i have build this model of zombie chorus and i just have like a feedback distortion when i play very loud my big string on my bass and that, just for a little time. I check out all the circuit and i didn't found anything wrong. And i don't know if is wierd but when i check the source voltage with my battery when all is plug (in and out jack), the voltage always go down slowly, like ,01V by sec. Thank you
ReplyDeleteHi Mark!. I like so much your web, is great. Well... I'm working in the Zombie Chorus original version, but I didn't find a 1uF polyester/ceramic capacitor, then I decided to bought one electrolytic, but I don't know how to connect it, in which position I've got to put it on?, negative or positive to output? Thanks a lot!!
ReplyDeleteYou should put the capacitor so that the negative goes to output.
Deletethis is no good aki. you'll lose half of your waveform that way considering the polarized cap would filter away the negative part of your signal.
DeleteThis was a year ago and I'm sure he got it sorted, but for the benefit of anyone reading this as they build.......That's not how it works. Capacitors, polarised or not, pass AC (guitar signal) just fine. Just look at any fuzz face schematic. Its the frequency content they affect. Larger value = more bass. You can use a polarised cap in any place where the voltage on one side (positive leg) is always higher than the other side (negative leg). Or make a non polarised cap by placing 2 polarised caps in series back to back.
Deletehi i need help on this one ! i just finished it and it works great but i get some hissing and the ticking, i did the original project, i need THIS schematic please, with the second vbias network specifically for the LFO IC, also i used tl072 instead of 062 and linear pots instead of log, coud that be the issue. someone help please !!
ReplyDeleteHere's another little demo: https://youtu.be/hSUPPEuxgPE
ReplyDeleteHi there! This is definetely a good one. However I think it´s cutting some treble. Is there some kind of lowpass filter cap to replace?
ReplyDeletethanks!
Anyone figure out how to have a blinking RATE LED?
ReplyDeleteHi all, I managed to get clean sound through, no effect at all...
ReplyDeletehere are the voltage reading for the ICs.
IC 1
8.9
6.6
5.07
0
0.1
8.9
8.86
8.88
IC 2
6.61
6.61
8.9
8.9
0
6.94
6.95
0
4.56
8.08
0
0
6.42
8.91
8.33
8.9
IC3
5.08
5.01
2.5
0
8.71
7.61
7.61
8.9
IC 4
4.48-5.3 (unstable reading)
4.6
4.5
0
4.3-5.3
3.4-5.5
8.9
I notice that pins 6-8 of IC 1 are different from the voltages posted here.
Also, for the LED+ wire, I just connect it to the anode of a RED LED and the other end connects to ground. It's on constantly as long as DC jack is plugged, is this right?
Any advise would be very much appreciated, Cheers!
This comment has been removed by the author.
ReplyDeleteDear guys, diyers and all of you :)
ReplyDeleteFirst thanks you for sharing your knowledge and projects, I appreciate it.
Second, I've been working on 3 of this zombie chours, all done on Mod 2 layout (vibe sw + mod sw).
The good news it's that all of them work pretty good, very nice sound and versatile usability.
The really bad news it's that all of them have ticking issues! :(
I've spent a lot of time on the problem without obtain nothing so i decided to write to you :)
I've made many experiments, here the tests and the responses
WITHOUT CHANGING ELECTRICAL COMPONENTS
1) Using an active pick-up guitar => ticking got muted, just a bit of hum, but it's ok!
2) prepending a buffered pedal (Boss like) => ticking got muted and a bit of hum
CHANGING ELECTRICAL COMPONENTS
1) tried TL062 vs TL072 = always ticking
2) changed MN3007 and CD4046 (may faulty but..) = always ticking
3) changed caps = always ticking
QUESTIONS:
1) could be a grounding problem?
2) coloud be a component problem (type of capacitor..etc)
how to solve or get an hint?
Thanks in advance to everyone
Luca :P
Surfing the blog, i've found these projects
Deletehttp://tagboardeffects.blogspot.it/2014/08/buffers.html
I've built all of them and they solve the ticking problem.
As for the other methods that i've mentioned before, it will add a bit of hum in background but stop the ticking.
At this point i've to choose if the pedal worth to be a buffered one or a true-bypass.
In the first case the buffer is placed directly on the input of the pedal, before the switch, so it will be always on, affecting the chain even "if the pedal switch is off".
intput jack --> buffer --> switch (wet/dry) --> output
The second option is to add the buffer only in the circuit of the effect, after the switch on the wet channel, leaving the dry inaltered.
intput jack --> switch (buffer + wet / dry) --> output
What's your idea about this two options? :)
ZOMBIE CHORUS TICKING ISSUE SOLVED + BLINKING LED:
ReplyDelete1) DE TICKING
There we go, after very a lot of time spent on debugging this effect I finally "solved" the main problem: the fucking ticking issue.
As said in the previous post, I've experimented the use of buffers to de-tick.
They will work, BUT ONLY IF YOU USE IT OUTSIDE the zombiechorus box (a standalone buffer box putted in serie before the zc).
They will not work if you try to embed it inside the same box, it will tick the same.
Strange to believe but that's it.
The reason why is due to a sort of EM-field created by the zombie circuit!
So if you want to get a standalone zombiechorus without buffer
THE ONLY WAY IS TO USE SHIELDED CABLES ON EVERY WIRE CONNECTION, OTHERWISE YOU HAVE TO SHIELD THE OSCILLATORS CHIPS.
The second way is not really affordable for obvious reasons (I don't know how to really shield a chip) so you have to use shielded cable (for dummies: not the simple one-wire cable normally used, but the one with 2 coaxial wires, simply ask for "shielded small diameter mono cable").
This will solve the tickin problem on every channel, remember the ticking on the true-by-pass channel? You will get rid of it too :)
NOTES:
Shielded cables are bit a larger and less flexibles but they will still fit in the same small box, just be precise.
NOTES:
You can avoid to use shield cable for: 9+, grounds and LED cables.
They will not really interested in the ticking problem.
IMPORTANT:
Remember to put every shield-wire TO GROUND.
2) BLINKING LED
According to all of this zc layouts you can see the pink LED+ wire on the rightmost bottom link:
following it on the link it will only touch a 2.2K resistor which will be connected only to the 5th PIN of IC4 where +9v comes, right? Yes, that means that the led+ wire it's just standard positive pole for led with the resistor already seried, nothing else.
You can remove the 2.2k resistor and the LED+ wire because we are going to set a new LED+ pole.
The new pole will be on IC2 PIN 10.
PIN 10 will not be at +9V direct current but it will be an alternate current around +4.4V.
So maybe you can use a lower value for resistor (100 or 220 ohm resistor will be enought), feel free to test the desired resistor value accorind to the led used too.
I hope this will help. Enjoy
Rake
BLINKING-LED NOTE:
DeleteNote that the 10th PIN of IC2 (CD4046 chip) is actually unused so draining tiny of current from it will not affect the circuit at all.
It is working like a charm without any problem! I use old MN3007 from Japanese yamaha pedal dm-100. I bought 2 MN3007 from ebay but are fakes. From which ebay seller do you buy working MN3007?
ReplyDeleteThank you Ivlark.
I am interested on getting a pair of them too, so if you know somebody, pelase share! ;) I'll do the same!
DeleteThis comment has been removed by the author.
DeleteHi, you can buy from here: https://www.utsource.net/search.aspx?keyWords=mn3007&page=1 $3.6
Deletehttp://bonsaiforum.gr/images/electronics/mn3007.jpg
and polida2008 ebay.
DeleteNever buy from polida on eBay. They used to be reliable, but have been known for selling either counterfeit, dead, or way out of spec components. Even though they are cheap, you'd be better off burning your money then giving it to them. Remember that if it's too good to be true, it is. They're way way way way too cheap, to the point it's not a deal it's s risk.
DeleteThis comment has been removed by the author.
ReplyDeleteI made it with mn3207 instead of mn3007. The sound (to my ears) is the same.
ReplyDeleteHey Everyone, I was wondering, would it be possible to add a switch that can set the speed to 0 and just use the depth to detune the signal? I've always wanted an effect like that...
ReplyDeleteHey Everyone, I was wondering, would it be possible to add a switch that can set the speed to 0 and just use the depth to detune the signal? I've always wanted an effect like that...
ReplyDeleteSo, i've seen many comments about a Blinking Led, but no straight answer about it, so here it goes; you can add a rate LED by doing one of those two things:
ReplyDelete1 - If you want a Bliking Led (on and off), you can do it with a little modification on the board: remove 2K2 resistor right before LED+ and change it for a 10K one, next step move the top side of the resistor from IC4 Pin8 line to IC4 Pin7 line (just go down one hole). There you go, a blinking LED on the same Rate of the effect.
2 - If you want a Fading Led (slowly fading brighter and less bright, my favourite! =D ), there are two ways; you can simply add a 10k resistor to Depth Lug 3, and the other side of the resistor is your new LED+. If you want to do on the board, it's a bit more tricky, but we can do it on the same board by doing four or five steps, that i plain to post here soon.
This comment has been removed by the author.
DeleteOk, as i promised, here is what you have to do in order to have your Fading Rate Indicator LED using the board:
DeleteStep 1 -> Move the 4M7 resistor that is connecting Rate 2 Lug to IC4 Pin 2 two steps to the left.
Step 2 -> Cut a trace between collums 3 and 4 of the last line. (don't cut hole 3 or hole 4, make a cut BETWEEN these holes).
Step 3 -> Put a 10k resistor where the 4M7 originaly was, but with it north pole connecting to IC4 Pin1 instead of Pin2 (you will move it one hole above).
The hole left on the new trace cut right on the left of south pole of the 10k resistor is your new LED+ pole.
I hope you guys can do it, fading leds are the best for Chorus effects! (:
Can you use the original status led in addition to a fading led off of depth lug 3?
DeleteSure, you can add this led to be always on as the rate indicator, and a second led to indicate on/off effect!
DeleteHow does the LED connect?
ReplyDeleteConnect the LED+ wire from the board to the positive end of the LED (the long leg), and you connect the negative end to the 3pdt switch, as per the offboard wiring diagram elsewhere on the site.
DeleteHi, do this pedal works for a bass guitar? thank you.
ReplyDeleteThis comment has been removed by the author.
ReplyDeleteWhat kind of caps can i use,stacked metal film from panasonic or MKT MKS.
ReplyDelete500pF on the switch can i use hete 470pF.
ReplyDeleteBuild this one and it Works.thanks for the Nice layout.
ReplyDeletehello, can anyone help me? i have built it, pretty sure that everythink is soldered properly, but its not workinh and my MN3007 is really hot after like 20 seconds and drains insane amounts of current. can anyone help me?
ReplyDeleteHey.
DeleteIve got the same issue. Did you manage to figure it out?
Just finished my first attempt at this pedal. I was expecting the 'vibe' to be 'Uni-Vibe' but I got 'Vibrato' instead which I'm very happy about.
ReplyDeleteA couple of questions:
1. I've got the dreaded ticking issue. From reading through the comments the only definitive fixes are to use a buffer pedal in front of this one or use shielded cables for all the wires - is this still the case?
2. Are the three speed modes "Normal / Leslie / Clone" as documented elsewhere for this layout? If so, how do these modes map to the toggle switch (if my switch is orientated as it is on the layout above)?
Thanks!
Just finished my first attempt at this pedal. I was expecting the 'vibe' to be 'Uni-Vibe' but I got 'Vibrato' instead which I'm very happy about.
ReplyDeleteA couple of questions:
1. I've got the dreaded ticking issue. From reading through the comments the only definitive fixes are to use a buffer pedal in front of this one or use shielded cables for all the wires - is this still the case?
2. Are the three speed modes "Normal / Leslie / Clone" as documented elsewhere for this layout? If so, how do these modes map to the toggle switch (if my switch is orientated as it is on the layout above)?
Thanks!
Just finished my first attempt at this pedal. I was expecting the 'vibe' to be 'Uni-Vibe' but I got 'Vibrato' instead which I'm very happy about.
ReplyDeleteA couple of questions:
1. I've got the dreaded ticking issue. From reading through the comments the only definitive fixes are to use a buffer pedal in front of this one or use shielded cables for all the wires - is this still the case?
2. Are the three speed modes "Normal / Leslie / Clone" as documented elsewhere for this layout? If so, how do these modes map to the toggle switch (if my switch is orientated as it is on the layout above)?
Thanks!
Hello Liam, actually I'm still trying to solve the ticking problem, I think that the major issue is in the small enclosures stompbox. I can't figure out why using a buffer inside the same enclosure won't fix the issue.
DeleteTry to use a large enough case to avoid overlapping components such as 3PDT/jacks/pots and PCB..
Actually chaining before a buffered pedal or using active pickups solve the issue, but it's a pain in the ass to don't figure out a good solution to make it de-ticked...
Maybe some help about the authors will help...
This zombie will be in my prio one of this days. Im gonna try mn3207 for this one and we'll see if my tweaking luck will not be down the drain ...jun fr Philippines. Cheers!
ReplyDeleteHey everyone, I have built the most modded version of this (with the 3-speed switch) and get a real nice chorus sound but get a background 'wailing' in time with the LFO. It changes in intensity when switching the speed and vibe switches, as well as when adjusting the rate and depth controls, and in some configurations, there is a harsher sound at the peaks of the LFO.
ReplyDeleteAny ideas on what I can do to eliminate this noise? (Or what I have done to create it!) I don't get any ticking fortunately, but the wailing makes the effect unusable for recording purposes. I don't know if it’s a fault on the board, or maybe increasing the 10uF capacitors would help?
I can measure and post voltages and have a recording of the noise if required.
Update:
DeleteStill not fixed, tried removing the LED on Depth 3 (which works well for showing the rate of chorus with a fading effect), in case it was adding noise, but alas, it wasn't the cause. This is the only additional mod I made to this circuit (on top of the ones included in layout).
I have also tried changing both 10uFs for 47uFs in hope, but this changed nothing. Is there any advice for what I can do next? I am considering making an audio probe at this stage to see where this noise is introduced. Can measure and post voltages upon request.
Many thanks,
Patrick
Hi there, I never resolved this noise issue. It could be described as a siren type noise and is in time with the LFO as the fading Rate LED I added shows this. It is not causing the noise as I removed it and there was no change. I could measure and add the Voltages of any relevant points if anyone thinks it may help diagnose the issue. I just wondered if there's anything that might generally create this weird siren-type noise? Other than that, the chorus works perfectly so this is bugging me. All the best and Happy New Year!
ReplyDeleteAquà alguien de Perú, hice el circuito y todo pero la guitarra no suena como deberÃa, ya revisé todas las conexiones y están bien, pero sigue sonando como si estuviese conectado directo al amp
ReplyDelete¿Eres capaz de medir voltajes? Si es asÃ, mida los voltajes en todos los pines de IC y transistor y publÃquelos aquÃ. Si necesita ayuda con esto, escriba un mensaje y haré todo lo posible para responder.
DeleteAún no pude medir los voltajes, de momento lo probé con la guitarra y me di cuenta que el IC3 se calienta a diferencia de los otros IC's.
DeleteEs el único que se calienta y mucho
Es inusual que solo se caliente IC3, que es uno de los TL062 (o alternativo).
DeleteCuando dijiste que se estaba calentando, inmediatamente asumà que serÃa IC1 el MN3007, ya que puedes obtener lotes malos de ellos.
De acuerdo, esto podrÃa deberse a algunas razones diferentes ... sin voltajes, es difÃcil decirlo, pero ¿puede verificar la continuidad? La configuración de resistencia más baja en un multÃmetro también funcionarÃa.
Recuerde que absolutamente no quiere que se encienda cuando pruebe la continuidad o la resistencia. Asegúrese de que el circuito esté desconectado de la alimentación. Verifique entre las conexiones de 9V y tierra para asegurarse de que no haya continuidad. (Si usa un medidor de resistencia, si se acerca a cero ohmios, entonces hay continuidad)
También puede verificar la continuidad entre los pines para ver si puede haber pequeños puentes de soldadura que causen que este IC se caliente.
De momento, revisé la continuidad en los pines de los ic's para ver si están cruzados pero no existe ningún cruce, limpié los posibles puentes de soldadura y ya no se calienta y ya da señal, ya lanza audio, ahora el problema es que no sale con el efecto además que al cambiar la posición del V Sw a desconectado deja de sonar
DeleteDe acuerdo, según el interruptor, dirÃa que solo obtiene la señal limpia sin el efecto adicional. VerificarÃa tres veces las conexiones alrededor de los circuitos integrados para asegurarme de que las resistencias y los capacitores estén en las filas correctas, etc. También verifique las conexiones de alimentación en IC4 como dijiste, ¿tal vez parece ser un problema? Esto podrÃa ser muchas cosas como: unión de soldadura en frÃo, cortocircuito de la señal de efecto a tierra o algunas otras cosas. Si los voltajes no son posibles, ¿puede publicar imágenes claras del circuito en ambos lados?
Deletecomo dije, verifiqué la continuidad tanto en los terminales de tierra como de vivo en ic4 y todo está correcto, voy revisando 1 semana seguida el orden de todos los componentes de acuerdo a los diagramas y sigo quedando de cuenta que están correctos, a menos que el ic4 esté defectuoso porque si le llega la alimentación.
Deletese puede publicar imagenes aqui?
https://drive.google.com/file/d/1ryyRUDO095p6seSL1skP9nbqPzX9BhHt/view?usp=sharing
Deletehttps://drive.google.com/file/d/1lTKfTOgLWce8SWyq5k_rqX0i5JgiZRPh/view?usp=sharing
https://drive.google.com/file/d/10-F5rfK1RM2fcTicVpHtxZJSNceCKZMp/view?usp=sharing
ahà están las imágenes
Debo añadir también que los potenciometros no cambian nada ni el tono
ReplyDeleteal hacer el rastreo del sonido, vi que el ic3 ahora funciona bien, al tocar las terminales de salida, genera ruido
ReplyDeletepero el ic4 es el que no envÃa ninguna señal, no se oye ningún ruido ni al tocar las terminales de entrada ni las de salida a diferencia del ic3 que si emite sonido
This thing sounds really cool. I built layout 1 and then added the vibe switch. I likee. Thank you for the layout.
ReplyDelete