Hi,
in building my own crybaby i started with classic circuit and then added 4 mods, almost classic ones : SWEEP, MID, GAIN, VOCAL.
As result, it is more a volume control rather then a wah pedal.
I need your help in sort out what is wrong there.
Here the circuit and the board I did with eagle.
I checked the schematic and it looks ok.
Debug on own Crybaby
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Ichabod_Crane
- Resistor Ronker
Something like that happend to me when I made a mistake with the ground of the footswitch, during the true bypass mod. Try to check the grounds.
Check the soldering.
Are you did the mods one by one? I recommended to do one mods at the time and test.
You could include the Volume Pedal mod, if you want.
I'm doing exactly the same kind of mods you did!
I have some doubt about the value of the pots, but I have still start to mod, I didn't change the originale transistors, nor the inductor.
I hope you solve the problems, and let us to know the results.
Check the soldering.
Are you did the mods one by one? I recommended to do one mods at the time and test.
You could include the Volume Pedal mod, if you want.
I'm doing exactly the same kind of mods you did!
I have some doubt about the value of the pots, but I have still start to mod, I didn't change the originale transistors, nor the inductor.I hope you solve the problems, and let us to know the results.
Thanks guys I sorted it out.
It was the inductor. I connected just 2 of 4 pins, by connecting pins together in couple it solves the issue.
Schematic above is now correct and verified
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Now my wah is sounding amazing !!
It was the inductor. I connected just 2 of 4 pins, by connecting pins together in couple it solves the issue.
Schematic above is now correct and verified
.Now my wah is sounding amazing !!
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Ichabod_Crane
- Resistor Ronker
Great!
Can you explain us some details?
About:
Mid Pot: the stock resistor in Cry Baby is 1.5k. You have a 1k resistor in series of a 2k pot. The midrange is 1k-3k. You used the lugs 1 & 2.
How it sounds?
Gain Pot: a 56R resistor is in series of a 1k pot, the lugs 2 & 3 have a 1k resistor in parallel. The range should be 56R-556R.
How it sounds?
Vocal Pot: a 33k resistor is in series of a 100k pot. You used the lug 1 & 2. The range is 33k-133k.
Is it not too much 133k?
Sweep caps: the Cry Baby stock is 10nF, 22nF is Jimi Hendrix and Zakk Wilde version, 68nF is for bass version.
It has sense use 4.7nF and 6.8nF?
Level Pot: why have you preferred to have the volume control at the end instead of to replace the first 68k resistor?
The schematic doesn't have a 4.7uF // 82k in parallel to the ground like Cry Baby stock schematic, but has 3.3uf // 680nF // 100k to the ground. Is there some reason?
Let me know if I wrote something wrong.
Thanks!
Can you explain us some details?
About:
Mid Pot: the stock resistor in Cry Baby is 1.5k. You have a 1k resistor in series of a 2k pot. The midrange is 1k-3k. You used the lugs 1 & 2.
How it sounds?
Gain Pot: a 56R resistor is in series of a 1k pot, the lugs 2 & 3 have a 1k resistor in parallel. The range should be 56R-556R.
How it sounds?
Vocal Pot: a 33k resistor is in series of a 100k pot. You used the lug 1 & 2. The range is 33k-133k.
Is it not too much 133k?
Sweep caps: the Cry Baby stock is 10nF, 22nF is Jimi Hendrix and Zakk Wilde version, 68nF is for bass version.
It has sense use 4.7nF and 6.8nF?
Level Pot: why have you preferred to have the volume control at the end instead of to replace the first 68k resistor?
The schematic doesn't have a 4.7uF // 82k in parallel to the ground like Cry Baby stock schematic, but has 3.3uf // 680nF // 100k to the ground. Is there some reason?
Let me know if I wrote something wrong.
Thanks!
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Ichabod_Crane
- Resistor Ronker
Please, someone may answer to my questions?
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poiureza
- Breadboard Brother
I did a lot of wah breadboarding recently.
I can't speak for the circuit above as I used a weaker inductance and strayed away from many standard resistor/cap values but here are my findings :
Mids : acts on all frequencies below the resonnant frequency. It also increases the width (lowers the Q) of the resonnant peak a bit when in heel position. After playing for a while I actually reverted it back to the standard 1.5K value because the "beefier" sound that you feel is actually detrimental to the quality of the wah effect.
Gain : I used a 100R resistor in parallel with a 1K pot. Again when you increase the gain it makes a beefier sound but removes from the actual wah effect. I prefer it fully clockwise (1.1K resistance) most of the time and use a distortion pedal afterwards if I really need some grit.
Vocal : that 33K resistor in parallel with the inductor. Changing that value made ZERO effect in my build but this might be due to my peculiar circuit.
Caps : The wah is a sensitive build. Just like all old circuits, it's pretty unstable and more of a happy accident than a well thought project. So slightly modifying one value in the circuit sometimes has a huge impact on the way it works (operating range, peak amplitude etc ). In my tweakings, I needed indeed to use values between 4n and 100n to make it work depending on what I did. In particular, the gain and mid pots push the operating frequency range all over the place, so it makes sense to have a couple of capacitor options to bring that range back in the desired spectrum.
Level : Ideally you'd have a level at pot at the input and one at the output since both do different things. He needs it at the output because he implemented a gain pot. You can get some serious volume increase for low Q1e resistance values. BTW regarding volume/clipping etc I prefer to replace the 68k input resistor by a 100K pot, instead of replacing the 470R Q1e resistor by a 1k pot. (involves then an input buffer of course)
Cap + resistor to ground : 3.3uF instead of 4.7uF makes a very subtle difference in the HF roll off (in my circuit at least). A non-topic
100K to ground instead of 82k has ZERO effect.
Eventually, I have no idea what the 680nF to ground brings. Very interesting, I have to check out that one.
I can't speak for the circuit above as I used a weaker inductance and strayed away from many standard resistor/cap values but here are my findings :
Mids : acts on all frequencies below the resonnant frequency. It also increases the width (lowers the Q) of the resonnant peak a bit when in heel position. After playing for a while I actually reverted it back to the standard 1.5K value because the "beefier" sound that you feel is actually detrimental to the quality of the wah effect.
Gain : I used a 100R resistor in parallel with a 1K pot. Again when you increase the gain it makes a beefier sound but removes from the actual wah effect. I prefer it fully clockwise (1.1K resistance) most of the time and use a distortion pedal afterwards if I really need some grit.
Vocal : that 33K resistor in parallel with the inductor. Changing that value made ZERO effect in my build but this might be due to my peculiar circuit.
Caps : The wah is a sensitive build. Just like all old circuits, it's pretty unstable and more of a happy accident than a well thought project. So slightly modifying one value in the circuit sometimes has a huge impact on the way it works (operating range, peak amplitude etc ). In my tweakings, I needed indeed to use values between 4n and 100n to make it work depending on what I did. In particular, the gain and mid pots push the operating frequency range all over the place, so it makes sense to have a couple of capacitor options to bring that range back in the desired spectrum.
Level : Ideally you'd have a level at pot at the input and one at the output since both do different things. He needs it at the output because he implemented a gain pot. You can get some serious volume increase for low Q1e resistance values. BTW regarding volume/clipping etc I prefer to replace the 68k input resistor by a 100K pot, instead of replacing the 470R Q1e resistor by a 1k pot. (involves then an input buffer of course)
Cap + resistor to ground : 3.3uF instead of 4.7uF makes a very subtle difference in the HF roll off (in my circuit at least). A non-topic
100K to ground instead of 82k has ZERO effect.
Eventually, I have no idea what the 680nF to ground brings. Very interesting, I have to check out that one.
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Ichabod_Crane
- Resistor Ronker
Thanks gor sharing.
I got a 500R pot to replace the gain resistor and I will use a 56R or so resistor in front of it. A 1.5k resistor in front of a 2k pot for the midrange.
A six position rotary switch for the sweep cap. From 10nf at 68nF.
I have still to decided about the vocal resistor. I didn't want to go under the 33k resistor, but somebody - pobably depeneds from the inductor - got a nice wah with clean channel setting this resistor to 0 Ohm.
I got a 500R pot to replace the gain resistor and I will use a 56R or so resistor in front of it. A 1.5k resistor in front of a 2k pot for the midrange.
A six position rotary switch for the sweep cap. From 10nf at 68nF.
I have still to decided about the vocal resistor. I didn't want to go under the 33k resistor, but somebody - pobably depeneds from the inductor - got a nice wah with clean channel setting this resistor to 0 Ohm.
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poiureza
- Breadboard Brother
Regarding the 33K resistor I only tested with bigger values : 33K and 100K gave the same result.
I did not test with lower values.
The outcome definitely depends on the inductor impedance that will be in parallel with this resistor.
I noticed that inductor DC resistance is extremely detrimental to the wah effect. It is way better to have a weak inductor (say ~300mH) with low DC resistance (say 50R), rather than a big inductor (~550mH) with larger DC resistance (say 200R).
I did not test with lower values.
The outcome definitely depends on the inductor impedance that will be in parallel with this resistor.
I noticed that inductor DC resistance is extremely detrimental to the wah effect. It is way better to have a weak inductor (say ~300mH) with low DC resistance (say 50R), rather than a big inductor (~550mH) with larger DC resistance (say 200R).
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poiureza
- Breadboard Brother
OMG I'm dumb ...
680nF to ground is simply to make a total of 3.3+0.68 = ~4uF
680nF to ground is simply to make a total of 3.3+0.68 = ~4uF
I suppose you meant to say that he removed the resistor, otherwise the inductor would be fully bypassed.Ichabod_Crane wrote: I have still to decided about the vocal resistor. I didn't want to go under the 33k resistor, but somebody - pobably depeneds from the inductor - got a nice wah with clean channel setting this resistor to 0 Ohm.
Last edited by poiureza on 22 Dec 2016, 12:21, edited 1 time in total.
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Ichabod_Crane
- Resistor Ronker
Somebody can tell me why sometime the Vocal mod doesn't do anything?
Thank you!
Thank you!
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poiureza
- Breadboard Brother
Hey, still working on the wah I see !
As for your question, one explanation I see is that the resistor is in parallel with the inductor ESR :
Say you typically have an inductor resistance of 200R and that 33k parallel resistor. Total = 198R
100k resistor in place of 33k will yield 199R instead : nothing noteworthy
Now take a 1k parallel resistor. Total will be 166R, the difference becomes notable and the Q moves accordingly (it gets sharper and higher but offset by part of the signal starting to bypass the inductor completely)
Just a first guess ...
As for your question, one explanation I see is that the resistor is in parallel with the inductor ESR :
Say you typically have an inductor resistance of 200R and that 33k parallel resistor. Total = 198R
100k resistor in place of 33k will yield 199R instead : nothing noteworthy
Now take a 1k parallel resistor. Total will be 166R, the difference becomes notable and the Q moves accordingly (it gets sharper and higher but offset by part of the signal starting to bypass the inductor completely)
Just a first guess ...
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Ichabod_Crane
- Resistor Ronker
Yes, I started just now the bigger mods. 
But I already put immediately in the output the Foxrox Retrofi. Of course my wah have a true bypass switch with the original buffer bypassed, too.
I have the stock inductor.
I tried the Variable Q like the Dime Wah, with any result. See the attach.
I didn't understandand your suggestion, sorry.
You didn't suggest me to replace the original resistor 33k with 1k pot, you did? The Vocal mod is an higher value of that resistor. About 68k, but people try different solution. A 100k pot should give me a large range, but with my surprise I got nothing! I can't explain how someone got a good effect and someone else not.
I guess it depends from the inductor. Myabe changing it with a Red Fasel (one I'd like) the Vocal pot could be work fine. Actually i don't want to spend a lot for this mod, especially if i'm not sure to get the effect I want.
But I already put immediately in the output the Foxrox Retrofi. Of course my wah have a true bypass switch with the original buffer bypassed, too.
I get exactly what you got. No changing at any setting of the 100k pot. A zero I got no wah effect, I already said all that.poiureza wrote:Regarding the 33K resistor I only tested with bigger values : 33K and 100K gave the same result.
I did not test with lower values.
The outcome definitely depends on the inductor impedance that will be in parallel with this resistor.
I noticed that inductor DC resistance is extremely detrimental to the wah effect. It is way better to have a weak inductor (say ~300mH) with low DC resistance (say 50R), rather than a big inductor (~550mH) with larger DC resistance (say 200R).
I have the stock inductor.
I tried the Variable Q like the Dime Wah, with any result. See the attach.
I didn't understandand your suggestion, sorry.
You didn't suggest me to replace the original resistor 33k with 1k pot, you did? The Vocal mod is an higher value of that resistor. About 68k, but people try different solution. A 100k pot should give me a large range, but with my surprise I got nothing! I can't explain how someone got a good effect and someone else not.
I guess it depends from the inductor. Myabe changing it with a Red Fasel (one I'd like) the Vocal pot could be work fine. Actually i don't want to spend a lot for this mod, especially if i'm not sure to get the effect I want.
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poiureza
- Breadboard Brother
No, I simply said that you should notice a difference with a 1k resistor instead of the stock 33k resistor.
And you should probably not notice any difference with 68k or 100k instead of the stock 33k resistor.
The variable Q circuit in the Dime wah does add series resistance which is detrimental to the wah effect (i.e. it lowers the resonance peak).
I don't think you'll want that (I'm pretty sure that, with the Q pot set at 1k, the pedal won't wah at all)
Yes, the inductor type is definitely very important in this pedal.
Sorry but I think the vocal mod is a hype.
What is really affecting the sound are both caps (that's exactly what Dunlop does in the 535Q-Wah) and the 1.5k mids resistor
And you should probably not notice any difference with 68k or 100k instead of the stock 33k resistor.
The variable Q circuit in the Dime wah does add series resistance which is detrimental to the wah effect (i.e. it lowers the resonance peak).
I don't think you'll want that (I'm pretty sure that, with the Q pot set at 1k, the pedal won't wah at all)
Yes, the inductor type is definitely very important in this pedal.
Sorry but I think the vocal mod is a hype.
What is really affecting the sound are both caps (that's exactly what Dunlop does in the 535Q-Wah) and the 1.5k mids resistor
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Ichabod_Crane
- Resistor Ronker
Sorry for the misunderstanding about your report.
Weird, I used to know that the Q Variable was very similar to the Vocal mod. Rather is the Sweep pot that reduce the wah effect. I seen some video on youtube some time ago and never tried other wah pedals. It should be easy watch again. other videos and check it up.
And you know? Today I was thinking I let go the Vocal pot mod, and instead, I want to insert, or at least to try, the Sweep pot. I know there are many pot, but it's fun make some experiment. This is the DIY, right?
Anyway, the Vocal mod remains a mistery!
Unfortunately the inductor is pretty expensive for a simple mod, so well the wah pot.
Definitely the Mid pot works. And the cap, but I got pop when I change it.
A thing I don't understand: the trnsistors. MPSA18 has very highe hfe. Somebody use transistor with lower hfe.
Weird, I used to know that the Q Variable was very similar to the Vocal mod. Rather is the Sweep pot that reduce the wah effect. I seen some video on youtube some time ago and never tried other wah pedals. It should be easy watch again. other videos and check it up.
And you know? Today I was thinking I let go the Vocal pot mod, and instead, I want to insert, or at least to try, the Sweep pot. I know there are many pot, but it's fun make some experiment. This is the DIY, right?
Anyway, the Vocal mod remains a mistery!
Unfortunately the inductor is pretty expensive for a simple mod, so well the wah pot.
Definitely the Mid pot works. And the cap, but I got pop when I change it.
A thing I don't understand: the trnsistors. MPSA18 has very highe hfe. Somebody use transistor with lower hfe.
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Ichabod_Crane
- Resistor Ronker
I have to report an issue.
Looking at the schematic in the first post we can see the resistor R12 56R in series to the Gain pot. That is a thing I initally tried, I didn't have 56R and I used a 47R, but with the Vocal pot at 100k I heard a pop noise (sounds sort a pop cap noise) in a certain position of the wah. So I lowered the Gain pot until the pop there was no more, the resistor of the Gain pot was exactly 82R. So I replaced my 47R qith a 82R.
Now I excluded the useless vocal pot (now there's the stock resistor 33k) and I tried to removed any resistors in front of the Gain pot, but I got agan the pop noise in a certain position of the wa. I guess is not a problem, I'm going to measure the resistor and put it in front of the Gain pot (47R probably will be ok, like when I didn't add the Vocal mod).
The question is: What is that pop noise when the gain resistor is very low?
Looking at the schematic in the first post we can see the resistor R12 56R in series to the Gain pot. That is a thing I initally tried, I didn't have 56R and I used a 47R, but with the Vocal pot at 100k I heard a pop noise (sounds sort a pop cap noise) in a certain position of the wah. So I lowered the Gain pot until the pop there was no more, the resistor of the Gain pot was exactly 82R. So I replaced my 47R qith a 82R.
Now I excluded the useless vocal pot (now there's the stock resistor 33k) and I tried to removed any resistors in front of the Gain pot, but I got agan the pop noise in a certain position of the wa. I guess is not a problem, I'm going to measure the resistor and put it in front of the Gain pot (47R probably will be ok, like when I didn't add the Vocal mod).
The question is: What is that pop noise when the gain resistor is very low?
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Ichabod_Crane
- Resistor Ronker
Escuse me, I would do an updating.
The thing I discussed above seems more complicated. This pop depends from the amount of the gain, the position of the midrange and the volume of the Foxrox Retrofit.
I got pop at higher gain (at low resistence); I got pop when the volume of the Retorit is within a certain level (at max reduce the danger of the pop); I got pop at intermediate values of the Midrange pot, (less problem at max or at min).
I tried some adjustment and I reach an kind of balance. Now the 500R Gain pot has a 470R resistor in parallel (between lug 1 and 3) and the new value is 245R. Max resistor is 395R, Min resistor is 180R. Unfortunately I get less gain than I would.
I did really like at 47R or even 82R, at least.
And this get the Volume pot less useful, because at min gain the volume has to be almost full to reach the unity volume, and at max gain I don't have too much volume to low too much the volume pot.
Of course the Volume pot is just to adjust the volume with the gain setting. I'm sorry about the amount gain.
The thing I discussed above seems more complicated. This pop depends from the amount of the gain, the position of the midrange and the volume of the Foxrox Retrofit.
I got pop at higher gain (at low resistence); I got pop when the volume of the Retorit is within a certain level (at max reduce the danger of the pop); I got pop at intermediate values of the Midrange pot, (less problem at max or at min).
I tried some adjustment and I reach an kind of balance. Now the 500R Gain pot has a 470R resistor in parallel (between lug 1 and 3) and the new value is 245R. Max resistor is 395R, Min resistor is 180R. Unfortunately I get less gain than I would.
I did really like at 47R or even 82R, at least.And this get the Volume pot less useful, because at min gain the volume has to be almost full to reach the unity volume, and at max gain I don't have too much volume to low too much the volume pot.
Of course the Volume pot is just to adjust the volume with the gain setting. I'm sorry about the amount gain.