Hi guys. TIme ago I bought an used CryBaby to modify, a lot!
True Bypass Foxrox Retrofit in the output done.
Now I started to mod other things. Gain pot, 500R with a resistor in front (82R); Mid pot, 2k with the 1.5k in front; Rotary Switch 6 position for range frequency; Volume/Wah switch.
And I had a great expectation about the Vocal Mod. I replaced the stock resistor with a 100k pot, but it doesn't do anything, except when is set to zero. The wah effect is cancelled.
How it could be possible? :icon_eek: I can hear the effect in the other CryBaby on youtube!
Schematic???
Schematic???
Schematic???
The CryBaby lovers knows what I'm talking about, but here it is.
This is interesting: https://www.electrosmash.com/crybaby-gcb-95
Schematic:
(https://www.electrosmash.com/images/tech/crybaby/cry-baby-wah-gcb-95-schematic-parts.jpg)
Frequency Range cap: C2
Gain resistor: R4;
Vocal resistor: R7;
Mid resistor: R2.
But the mods are here: http://stinkfoot.se/archives/549
IMHO, you don't have to be a "Cry Baby Lover" to see, when R7 is set to zero, L1 is short-circuited..
Thanks!
Do you mean this could explains the no wah effect to zero setting?
Of course..
Wah effect is primarily created due to 500mH inductor "self-resonance" in conjunction with R7/C3/R8 (LRC filter).
When R7 is set to zero Ohms, the whole current coming through R6 is going right to GND..
(not splitted through L1 and the other relative items.. - it's like to have L1 taken out of the circuit.. )
I always found the vocal mod to be the most useful and pronounced mod. That said I hate the crybaby and bought a vox and never looked back.
I can't measure the resistance of the pot through the board, (I guess beacuse the inductor), but I verified the connection of the pot with several spot: C2, R2, and C3.
I thought the inductor is the issue, but I hope I wrong, because I don't want to spend money for the a red fasel or someone else, too expensive, now. To the otherside the vocal po is useless.
(Actually, I have another little issue. The gain pot crackles, but works.)
Quote from: Elijah-Baley on December 04, 2017, 06:23:49 AM
The gain pot crackles, but works.
DC leakage..??
(through C5 or/and C4..)
???
The pot works fine and I can measure the right resistance on the board. The other lug goes to the ground.
I didn't touch C5 nor C4.
The work had to be simple, but not I'm beginning to worry.
If you replace R7 with 100k pot, it should work. I added 27k (or 22k, can't remember) in series with mine, because anything below that is pretty much useless. When in doubt, go back to 33k, check that it works as usual, then do the mod. No way you cna go wrong.
Quote from: Juan Wayne on December 04, 2017, 09:43:43 AM
[...] No way you cna go wrong.
Indeed. I don't understand why it doesn't work. it just cancel the wah if set to 0R. I'll go back with the original, but it is a dead end.
The cancelling effects is actually normal, that's why I use a "minimum" resistor in series. However, just to be on the same page (and because I've spent so many hours cursing at unplugged equipment that worked perfectly it's not even funny), are you attaching the pot in place of R7, with no R7 in place? By this I mean, getting rid of R7 completely and using the same holes to connect the pot, acting as a variable resistor, affecting the Q of the filter.
Also, how ironic is it that I said "No way you CNA go wrong"? I can't even spell right, talk about messing with electricity and shit.
I taken off the R7 resistor, a wire from the lug 1 of the pot and one of the hole, and a wire from the lug 2 and the other hole. Lug 3 is unused. Maybe it is wrong?
Same method for the Mid pot and the Gain pot.
Pics tomorrow.
I'm as puzzled as you. Maybe pic will help then.
For a while my wah had a 33k fixed with a 50k pot (variable resistor) in series. I found the effect to be quite subtle. I kept going back to 33k, so I took the pot out.
The old wahs started with 100k, but moved to 33k within a few years. Of all the wah sounds you've heard on records your whole life, probably >99% of them had a 33k.
QuoteI hate the crybaby and bought a vox and never looked back.
What's the difference? The circuits of both have changed many times over the decades. For at least one long stretch, they were the exact same product with different branding and cosmetics.
cutting to the chase cuz i'm an asshole. ;)
dude, don't use a pot for the vocal mod. its pointless. stick a big resistor in there, be done with it.
as others have pointed out, with the pot all the way down, its GOTTA kill the circuit cuz you're shorting it out ;)
Quote from: thermionix on December 04, 2017, 03:23:50 PM
For a while my wah had a 33k fixed with a 50k pot (variable resistor) in series. I found the effect to be quite subtle. I kept going back to 33k, so I took the pot out.
[...]
Initially I had decided for a combination more ore less like yours, using resistor + 50k pot, then I convinced myself to use the highest range: 0-100k.
Actually, I heard this story about the subtle ot this mod sometimes, but at the same time some demos can disprove us. Indeed, somebody decided to keep the stock resistor, somebody use an alternative value and somebody use pot or resistor + pot.
This is the reason I say it could be the inductor type, but this is only a supposition. In my CryBaby there's a dark red one, on it there's written "FASEL". I don't think is the Red Fasel, but just the stock.
Quote from: pinkjimiphoton on December 04, 2017, 04:39:34 PM
cutting to the chase cuz i'm an asshole. ;)
dude, don't use a pot for the vocal mod. its pointless. stick a big resistor in there, be done with it.
as others have pointed out, with the pot all the way down, its GOTTA kill the circuit cuz you're shorting it out ;)
Thanks for yout post. 8)
As we can see someone use a pot. I could use a 22k + 50k pot, for example. But the problem is that modding the resistor I don't get any changing, and I found it weird. In this case I can settle with the stock resistor, but I really would a sort of Q pot.
Try to look here:
(http://i.imgur.com/0COFT.jpg)
There's an alternative way to set the Q. Look the 1k pot for the Variable Q. That could be the same work of the Volcal pot, but, maybe, the position is a bit different. And maybe it could work?
This doesn't explain why sometime the Vocal mod is more than subtle.
Pictures.
The wires of the Vocal pot are under the board, I soldered them twice because the issue, and the second time it's been easy solder them like that
(https://i.imgur.com/9GyMIAO.jpg)
(https://i.imgur.com/JwJSn0H.jpg)
Tell me about the Q pot of the Dime Wah version.
Quote from: Elijah-Baley on December 04, 2017, 05:03:51 PM
As we can see someone use a pot.
As we can also see, "he" uses the pot IN SERIES with the inductor..
(and the whole arrangement through 1k5 resistor to Q1 base..- "he" actually trims the overal NFB loop for a variable Q)
That's totally different arrangement than the one with Resistor/Pot IN PARALLEL with the inductor 'cause in this case "he" only can add resistance to the inductor and not short-circuit it, in any pot setting... :icon_wink:
I guessed, I was sure this Q pot was different, I meant that the someone uses the Vocal pot as I wanted.
Is it normal that the two sides of the inductor are in contact?
Quote from: Elijah-Baley on December 05, 2017, 08:10:45 AM
Is it normal that the two sides of the inductor are in contact?
They shouldn't be..
You've probably checked them with continuity tester (beeper) so you've got an audio signal but also some resistance reading..
So, the thing is suspect. ???
The beeper beeps when I touch the two pins of the inductor, on the board, of course. But also the lug 1 and 2 of the pot result in connected. I treid to measure the resistance, and on the inductor measure as the pot.
It seems that the pot has put in contact the sides of the inductor each other.
Tomorrow I'll try to desolder the vocal pot, but not the wire. I have available the stock 33k resistor and some other value, and even a 50k pot. I have to make some experiment to understand what is happening.
I add a layout + schematic found in the web.
I don't have really follow this schematic, but accidentally, it was really close to my intentions, so a bit I was inspired.
(https://s18.postimg.org/gpam6ajad/Wah_Mod.jpg) (https://postimg.org/image/gpam6ajad/)
The inductor has a fairly low DC resistance, probably low enough to get a beep from a continuity tester. You should measure resistance, zero ohms means it's shorted somehow. I can't remember a number specifically, but I think a working wah inductor is usually a few hundred ohms.
Other than that, seeing that you have true bypass and the FoxRox output buffer, I would HIGHLY recommend omitting the input buffer. Your wah will be less subtle overall, probably the "vocal mod" would be too.
So the inductor is ok. :( And then the Vocal mod doesn't work.
The input buffer is already omitted. The input start from that red cap.
My bad, I saw 3 transistors and assumed you still had the input buffer.
No worry! ;)
Now I don't know what to do... :-[
Here the PCB, meanwhile I can study a method to replace the Vocal pot method with the Variable Q method. And I hope that will work! :icon_eek:
(https://www.electrosmash.com/images/tech/crybaby/dunlop-crybaby-gcb95-pcb.jpg)
I avoid to draw the layout with the Variable Q pot beacuse even this doesn't work. :-[
I tried to rotate the wah pot some step higher, for more open sound. Maybe the Vocal mod start to hear? Maybe very subtle? I'm not sure, anyway. But I don't like this wah pot settings. Too much treble, hurt the ears.
Did someone use a working Vocal pot?
I'm still confused. Looking at your board compared to the stock GCB-95 it sure looks like you are still going through the input buffer. Have you cut traces under the board and just bypassed it with wire?
Yes, there's a cut track. You can find this method on the web.
No worry about it. ;)
Dig.
Ok, for my CryBaby let go the Vocal mod. For the moment, at least.
I know it's not the main topic, but can we manage a couple of things?
Quote from: antonis on December 04, 2017, 06:41:23 AM
Quote from: Elijah-Baley on December 04, 2017, 06:23:49 AM
The gain pot crackles, but works.
DC leakage..??
(through C5 or/and C4..)
I got a sort of white noise while I turn the gain pot. It's pretty weird, coulde be the little 500R pot? I'd exclude mistakea, even this time. I just replace the resistor with the pot and a resistor in front. Is this noise normal. :o
Another little issue is the pop when I switch the cap with the rotary. This I would absolutely solve it. It is like if an hammer hit a little tin can box ;D.
I guess I need one or more resistor, but I didn't get how I should connect them.
I found these schematics with a solution, a bit different, and I don't know if they are verified.
(https://s8.postimg.org/5wbh3iwpd/tegaki.jpg) (https://postimg.org/image/5wbh3iwpd/)
(https://s8.postimg.org/44ii8oash/ivl2md.gif) (https://postimg.org/image/44ii8oash/)
The gain pot adjusts Q1 emitter resistance, right? It would have DC on it by nature, no leaky cap required. So, not a bad pot, just don't adjust it in the middle of a song.
Is your rotary switch Make Before Break, or Break Before Make? Probably the latter. The resistors might help tame the pop, but it still won't be something you want to switch while playing.
About the gain pot, it sounds weird to me because I never heard about its scratchy or noise during the adjustment. Nor seen it on some video.
This is the rotary switch: https://www.musikding.de/Rotary-switch-2P6T-open
I don't remember the kind, I bought it a lot of time ago, maybe for a Rat.
I will not adjust the gain "while" I play, neither to turn the rotary switch, but at least I would adust it when the wah is engaged, and these two noise are a bit annoying. Not too much the gain pot, but the pop, at the beginning it is enough loud, then less. Of course I could turn three or four times the rotary switch, so it will be almost silent, and I can settle like that for the moment. But it's not the perfection, I would to know how fix this issue.
Sorry, I ask again: is there a verified method?
Update:
I just found this wah pedal.
The brand has some wah version and this has some of the mods I want in my CryBaby. I can hear exactly the same pop when the cap changes (around 2:00 and 6:00), and when it ajdust the gain (around 3:43) when the same noise.
It has even the Sweep control to smooth the wah effect. Right in these days I was thinking about it. You can see that control in the Dimebag version CryBaby.
> I don't know if they are verified.
What do you want, a note from the Dalai Lama? Just try it.
Of course, in case I'll try. ;)
It just for saving time. I have just those caps and I want make a clean work, probably I'd do another board if one of those tricks work. I can use the breadboard. We'll see.
Meanwhile I'm planning to let it go the Vocal mod and make the Sweep pot like the Dimebag CryBaby version, or the Wilson Wah posted above.
Quote from: thermionix on December 10, 2017, 09:55:01 PM
The gain pot adjusts Q1 emitter resistance, right? It would have DC on it by nature, no leaky cap required. So, not a bad pot, just don't adjust it in the middle of a song.
Is your rotary switch Make Before Break, or Break Before Make? Probably the latter. The resistors might help tame the pop, but it still won't be something you want to switch while playing.
I should buy a new Make-Before-Break rotary switch, I need it also because the one I have got has the shaft too long and the knob are very high.
I have almost finished, I have just to adjust the resistor gain pot.