Here's a collection of vero (stripboard) and tagboard guitar and bass effect layouts that we have put together covering many classic and popular effects in growing numbers. Many of these have been posted on freestompboxes.org, so check that site out for great discussions on building your own effect pedals. Enjoy the builds and please also visit us on Facebook and Twitter
In the words of Prescription Electronics, the COB: "allows its user to blend a clean guitar signal with a pure upper octave at the preferred balance including output and overdrive levels. Noise free and compatible with your favorite stompboxes!"
This one here is a hard call, since there is no sample clips about it around to compare it to.. But i think i can call it.
It's neither a fuzz, nor a digital synth style super clean ring modulation / octave up, but it's clean enough to call it an octaver. 1M for octave pot seems to be a bit too much - and it should be wired the other way around. One can just cut the link between lugs 3 and 2 - and solder a new one between 1 and 2. If i box this, i'll probably swap that pot for 500K or maybe even smaller..
One other thing is that i got it to go a bit less fuzzier with 2N5089s. So as always, the sockets and the trial/error may be the best option to find what works the best. Just be sure to check out the pinouts :)
Might be much better effect with/for bass.
Anyway. The layout works. Mark. Congratulations! You're THE MAN. No one else on the planet has drawn 200 verified guitar effect layouts for tagboard and vero! I thank you from the bottom of my heart. Your layouts and advice here on the blog have taught me a lot and i really appreciate it. Thank you. And keep 'em coming - I'll be building! +m
Hey, just quick a note: I built this not on veroboard but on a PCB, and as mirosol suggested I had to go down to B50K on octave pot so it works as intended. If I hadn't done so and used B1M, the octave effect was only noticeable on the last 5% of rotation... Maybe it has something to do with hfe of those trannies, I really don't know but I used 2n3904's with around 220. just a guess...
They work better but while I had the two types of transistors together I tried combinations of the two. I ended up with Q3 standard, and the rest 5089.
For subtle textural use, (much clean signal) this it is the right kind of fizz in the fuzz to layer the octave effect under the clean signal like a keyboard comb filter sound.
Just built it, altho I used nte123a's (that's all I had laying around). They don't work so good in it :-) Gonna try again with 5089s today. Thank god for transistor sockets, right?
Just built it, altho I used nte123a's (that's all I had laying around). They don't work so good in it :-) Gonna try again with 5089s today. Thank god for transistor sockets, right?
Yes you're right, thanks for the heads up. If you move the top left hand 10u cap one column to the left then the 4K7 can go in that gap. I'll make the correction now.
Yea, this little 4k7 change sound, more octave just like demo!!! I'm just soldered on jumper to ground And no needs modify vero. Sorry for my English :-*
In the same box, this circuit with robot devil in parallel (clean inputs in two effects and mixing signal in output jack) it's great!!! (believe me, not noise box, very usable)
I followed this layout to the letter and, while I have sound - volume controls and what seems to be the blend, I get no octave at all. I'm using 3904s as well. Any ideas?
I found the problem with my build. I had the 4k7 resistor from Q4 connected to the base instead of the emitter. I move both it and the diode down one row, I now have the upper octave. It was a tight squeeze getting it into a 1590b along with a battery. I'm gonna box this up properly without the space for a battery. Nice sounding pedal.
Checked some youtube demos, seems like a nice pedal. I'm thinking of building an ultimate fuzzbox based on a fuzz face. Might be worth thinking about pairing it up with this. Dedicated switches for both. That would be awesome.
Hello, I have built it today. I work with amplitube, my guitar direct in this COB, and i doesn't have any octave. Volume work, blend too, but octave doesn't work. I've checked all my build, and no mistake...
Just built this and damn, what a nice tone for guitars! I'm having a slight issue with the clean channel though where the octave kinda breaks up in a strange ring modulator kinda way. It straight doesn't work with chords either. I actually intended to use this for my ibanez tmb30 which I modded into a bass vi, but it barely works with the lower notes. Can anyone suggest and resistor or cap changes to improve this? Just to note, I used 2N5089s as per mirosol's suggestion.
are you sure you have the transistors right? The pic is wrong but the CBE is right i went by the pic the first time and it worked but was crazy like your saying double check your transistors make sure CBE is right not the pic
thanks billy, got her working ..finally .it sounds really good ..like a green ringer but you can give it a little hair ..they are essentially the same pedal but thanks to doyle B we have to add a volume on it lol..and i finally got the Epi to stop buzzing and intonate ..was truss rod needed more relief on it ..like 3 whole turns but its plays good now
seems the sweep on the range starts around 40-50% ..I tried a bunch of things , like everything lol and cant get a full rotation. I think its the nature of the beast. I have made 4 of these now and all with 2n5089's around 500-650 ..there seems to be a small sweet spot buts it an oh so nice must have sweet spot ..the volume knob doesnt do a whole lot? im guessing its more for an amp to amp thing and fx loop thing?
Hey all, really hoping to get this working, as far as I can tell I'm 100% to the layout above and have added the 4k7 to ground from q4, getting volume but no octave/fuzz to blend. The transistors have me confused I have q3-4 as per CBE above but still no good. Any help greatly appreciated.
So... I built this and I used the 2n3904’s at first but it sounded pretty much like a low quality fuzz with a bit of octave but really not where it counted. It’s probably my cheap Chinese stock, however…
I sat and had a really good dig through my transistors and came up with a strangely sweet combo!
In the end I settled for Q1 BC108B Q2&3 Germanium BC109C Q4 2N2222
My intention was to use this pedal as an addition to a fuzz. Having the blend function makes this effect ideal for placing in front but I was concerned by the amount of gain being added to my fuzz. So I flipped a bunch of trannies.
I might add a pre gain knob or a mosfet boost/cut in front to allow for more control on the fly. But like this she’s a squealing octave beast but not massively harsh or gainy. Hope someone else try’s it this way, if only to prove I’m not mas ��
Really!? Dude that surprises me because mine are a lot darker than my silicones. If that’s true then I find this pretty cool! Tbh I hadn’t checked the data sheet I just had some laying about from a previous build. Rest assured I’m very happy at how it’s turned out :) not harsh anymore with clear octave almost throughout my fretboard \m/ The BC108B I used was a plastic but yes the 2 BC109C (just had a look and...) are indeed silicone metal can!
Just finished it. I love the way it oscillate with 2n3904 ! Very nasty little thing ! I needed a quick win before heading back to my tremolo project :) Many thanks :)
Mythos Argo is based on this I believe. Nice highly defined octave. The transistors have a huge impact on how much octave you can get. If you are having trouble hearing it you probably need to change them or fix something. I tried out several combos. Was looking for the balance between pronounced octave and mild OD somewhere in the Green Ringer range. Seems like Hfe of c.180 was my sweet spot. I did match them after I got to the finalists. Which were: 2n4401@190, 2n3904 a little hot, PN2222A@180, 2N4123@80. I went with the PN2222A's for the clarity, pronounced octave (even with the gain down), nice touch sensitivity, ability to clean up with the blend down and just enough grit when fully up. Turns out that I dropped one. Looked around and found it, I thought. Ended up with one 4402 in Q4 and couldn't beat it with any other combo. If you are looking for more of an octave fuzz combo the ROG Buzz Box has about 10 parts, gets a strong octave and it rips.
This one here is a hard call, since there is no sample clips about it around to compare it to.. But i think i can call it.
ReplyDeleteIt's neither a fuzz, nor a digital synth style super clean ring modulation / octave up, but it's clean enough to call it an octaver. 1M for octave pot seems to be a bit too much - and it should be wired the other way around. One can just cut the link between lugs 3 and 2 - and solder a new one between 1 and 2. If i box this, i'll probably swap that pot for 500K or maybe even smaller..
One other thing is that i got it to go a bit less fuzzier with 2N5089s. So as always, the sockets and the trial/error may be the best option to find what works the best. Just be sure to check out the pinouts :)
Might be much better effect with/for bass.
Anyway. The layout works. Mark. Congratulations! You're THE MAN. No one else on the planet has drawn 200 verified guitar effect layouts for tagboard and vero! I thank you from the bottom of my heart. Your layouts and advice here on the blog have taught me a lot and i really appreciate it. Thank you. And keep 'em coming - I'll be building!
+m
Top man, I'll do the corrections and tag it. 200th post coming! :o)
DeleteHey, just quick a note: I built this not on veroboard but on a PCB, and as mirosol suggested I had to go down to B50K on octave pot so it works as intended. If I hadn't done so and used B1M, the octave effect was only noticeable on the last 5% of rotation...
DeleteMaybe it has something to do with hfe of those trannies, I really don't know but I used 2n3904's with around 220. just a guess...
Just finished making this - fired up first time! I'm looking for subtle textural effects and this is really good for that.
ReplyDeleteUse this into a clean amp with the fuzz and the octave just there, add the right kind of reverb and echo, and you really notice if you switch it off.
Our band will use this in the quieter/dramatic moments.
Thanks Mark. Three quarters of our main guitar pedalboard is full of the goodies from this site.
I took Mirosol's advice and tried 5089's.
ReplyDeleteThey work better but while I had the two types of transistors together I tried combinations of the two. I ended up with Q3 standard, and the rest 5089.
For subtle textural use, (much clean signal) this it is the right kind of fizz in the fuzz to layer the octave effect under the clean signal like a keyboard comb filter sound.
There are a couple of YouTube demos, this thing actually sounds pretty good.
ReplyDeleteJust built it, altho I used nte123a's (that's all I had laying around). They don't work so good in it :-)
ReplyDeleteGonna try again with 5089s today. Thank god for transistor sockets, right?
Just built it, altho I used nte123a's (that's all I had laying around). They don't work so good in it :-)
ReplyDeleteGonna try again with 5089s today. Thank god for transistor sockets, right?
which are the best values for the potentiometer then the octave? 500k?
ReplyDeletewhich are the best, the 2N5089 or 2N3904 transistors?
thank you very much my friends
In the scheme, appears resistance 4k7 from emitter of q4 to ground.????
ReplyDeleteGreat blog (like a dream)!!!!
Yes you're right, thanks for the heads up. If you move the top left hand 10u cap one column to the left then the 4K7 can go in that gap. I'll make the correction now.
DeleteYea, this little 4k7 change sound, more octave just like demo!!!
DeleteI'm just soldered on jumper to ground
And no needs modify vero.
Sorry for my English :-*
In the same box, this circuit with robot devil in parallel (clean inputs in two effects and mixing signal in output jack) it's great!!! (believe me, not noise box, very usable)
ReplyDeleteHey,
ReplyDeleteI followed this layout to the letter and, while I have sound - volume controls and what seems to be the blend, I get no octave at all. I'm using 3904s as well. Any ideas?
And then the glitch makes itself known. Forgot to add the left ground from the board and switch the lugs on the octave pot. AMAZING SOUND!
DeleteI built this one the other day. it sounds awesome. just waiting til Monday when the enclosure arrives to box it up. thanks for posting it.
ReplyDeleteI got it completed today. I really dig this one.
ReplyDeletepics:
http://johnkvintageguitars.homestead.com/Effects/Fuzz-ODs/COB/COB-01.jpg
http://johnkvintageguitars.homestead.com/Effects/Fuzz-ODs/COB/COB-02.jpg
i am confused about q1, q2, q3 and q4 on the layout, why we see cbe and ebc if they are the same and positioned the same way?
ReplyDeleteJust follow the pinout for the 2N3904. Q3 and Q4 are positioned the opposite way round to Q1/Q2 despite the way they look in the layout.
DeleteI'm having some trouble getting any upper octave at all.
ReplyDeleteI should add that I have swapped the 1M pot for a 250k Lin and still no better.
DeleteI found the problem with my build. I had the 4k7 resistor from Q4 connected to the base instead of the emitter. I move both it and the diode down one row, I now have the upper octave. It was a tight squeeze getting it into a 1590b along with a battery. I'm gonna box this up properly without the space for a battery. Nice sounding pedal.
ReplyDeleteCould this be used to make a shimmer reverb, with the reverb full wet in a parallel loop?
ReplyDeleteChecked some youtube demos, seems like a nice pedal. I'm thinking of building an ultimate fuzzbox based on a fuzz face. Might be worth thinking about pairing it up with this. Dedicated switches for both. That would be awesome.
ReplyDeleteHi, could someone share schematic for COB.. I cannot find it anymore :/
ReplyDeleteHello, I have built it today. I work with amplitube, my guitar direct in this COB, and i doesn't have any octave. Volume work, blend too, but octave doesn't work. I've checked all my build, and no mistake...
ReplyDeleteJust built this and damn, what a nice tone for guitars! I'm having a slight issue with the clean channel though where the octave kinda breaks up in a strange ring modulator kinda way. It straight doesn't work with chords either. I actually intended to use this for my ibanez tmb30 which I modded into a bass vi, but it barely works with the lower notes. Can anyone suggest and resistor or cap changes to improve this? Just to note, I used 2N5089s as per mirosol's suggestion.
ReplyDeletedouble check the electrolytics. I had a cap in backwards once it did what your saying . you may be using too hot of transistor try the 2n5088
Deleteare you sure you have the transistors right? The pic is wrong but the CBE is right i went by the pic the first time and it worked but was crazy like your saying double check your transistors make sure CBE is right not the pic
Deletetry at least backing down q3 to a lesser gain like a 2n3904 or 2n5088 .
ReplyDeleteDoyle Bramhall II uses this, and Experience, alot so... just listen him.
ReplyDeletethanks billy, got her working ..finally .it sounds really good ..like a green ringer but you can give it a little hair ..they are essentially the same pedal but thanks to doyle B we have to add a volume on it lol..and i finally got the Epi to stop buzzing and intonate ..was truss rod needed more relief on it ..like 3 whole turns but its plays good now
ReplyDeleteJust built this with 2n3904's. Really nice, very useful, thanks for the layout!
ReplyDeleteseems the sweep on the range starts around 40-50% ..I tried a bunch of things , like everything lol and cant get a full rotation. I think its the nature of the beast. I have made 4 of these now and all with 2n5089's around 500-650 ..there seems to be a small sweet spot buts it an oh so nice must have sweet spot ..the volume knob doesnt do a whole lot? im guessing its more for an amp to amp thing and fx loop thing?
ReplyDeleteCant believe i missed this bad boy! Love it! 5089,s all the way through.
ReplyDeleteHey all, really hoping to get this working, as far as I can tell I'm 100% to the layout above and have added the 4k7 to ground from q4, getting volume but no octave/fuzz to blend. The transistors have me confused I have q3-4 as per CBE above but still no good. Any help greatly appreciated.
ReplyDeleteFigured it out, silly mistake read the 1u and 1n caps both as 1u, much better now
ReplyDeleteDo you have the actual schematic for the COB? Where does the switch connect? I'd like to do this in Altium.
ReplyDeleteBrossart once said that Q3 and Q4 was matched so... that might be something to look into!?
ReplyDeleteGoing a little bit lower on these two (talking hFE) might be an good idea as well.
250K Mixing pan not working? What is the problem as if you are carrying a volume adjustment task? please help
ReplyDelete250K Mixing pan not working? What is the problem as if you are carrying a volume adjustment task? please help
ReplyDeleteJust built this and audio passes, but no octave. I've double checked my connections and I can't find anything wrong. Any Ideas?
ReplyDeleteHi everyone��
ReplyDeleteSo... I built this and I used the 2n3904’s at first but it sounded pretty much like a low quality fuzz with a bit of octave but really not where it counted. It’s probably my cheap Chinese stock, however…
I sat and had a really good dig through my transistors and came up with a strangely sweet combo!
In the end I settled for Q1 BC108B
Q2&3 Germanium BC109C
Q4 2N2222
My intention was to use this pedal as an addition to a fuzz. Having the blend function makes this effect ideal for placing in front but I was concerned by the amount of gain being added to my fuzz. So I flipped a bunch of trannies.
I might add a pre gain knob or a mosfet boost/cut in front to allow for more control on the fly. But like this she’s a squealing octave beast but not massively harsh or gainy. Hope someone else try’s it this way, if only to prove I’m not mas ��
just an FYI. BC108B'S and BC109C's are NOT germanium. they're metal can silicon transistors
ReplyDeleteThis comment has been removed by the author.
Delete*Sorry recompiled my reply
DeleteReally!? Dude that surprises me because mine are a lot darker than my silicones. If that’s true then I find this pretty cool! Tbh I hadn’t checked the data sheet I just had some laying about from a previous build. Rest assured I’m very happy at how it’s turned out :) not harsh anymore with clear octave almost throughout my fretboard \m/ The BC108B I used was a plastic but yes the 2 BC109C (just had a look and...) are indeed silicone metal can!
This comment has been removed by the author.
ReplyDeleteJust finished it. I love the way it oscillate with 2n3904 !
ReplyDeleteVery nasty little thing !
I needed a quick win before heading back to my tremolo project :)
Many thanks :)
Mythos Argo is based on this I believe. Nice highly defined octave. The transistors have a huge impact on how much octave you can get. If you are having trouble hearing it you probably need to change them or fix something. I tried out several combos. Was looking for the balance between pronounced octave and mild OD somewhere in the Green Ringer range. Seems like Hfe of c.180 was my sweet spot. I did match them after I got to the finalists. Which were: 2n4401@190, 2n3904 a little hot, PN2222A@180, 2N4123@80. I went with the PN2222A's for the clarity, pronounced octave (even with the gain down), nice touch sensitivity, ability to clean up with the blend down and just enough grit when fully up. Turns out that I dropped one. Looked around and found it, I thought. Ended up with one 4402 in Q4 and couldn't beat it with any other combo. If you are looking for more of an octave fuzz combo the ROG Buzz Box has about 10 parts, gets a strong octave and it rips.
ReplyDeleteI originally used a B500k for the Octave. Switched to a B250k for a lot more even play from 30% to 100% up.
ReplyDelete