Cry Baby Original

[Goodrat]

A friend at work let me borrow one he had in his closet since the 80's.
So I'm sharing what was in it, in case it is helpful for any info
(other than the tons of info out there).
He wants to sell it. It is scratchy, not modded  and not sounding as well as my new one.
These values match the patent values.

http://www.rickviola.com/images/OriginalCBpic.JPG


http://www.rickviola.com/images/OriginalCBschem.jpg

[Goodrat]

After playing it, I can see why everyone wants to increase the gain on the older units.
However, on mine, with the op amp buffer and SMD board, it needs less gain because humbuckers will overdrive it.
The old had less wah range, I think, but the pot doesn't have those couple of steps though the range like my new one.
I should get a better pot for mine.
Maybe I should give him $20 for the enclosure.

After looking at this on a scope and signal generator, I think I realize something.
Increasing gain in the Wah circuit is not a good thing. It starts to clip on the top peaks.
What this needs is less gain in the wah, or less signal into it, then an output amp/buffer stage to make up for any volume loss.
That's my take on it. Great invention, but I think they cut corners.

[joegagan]

this is the era crybaby that caused ken fischer to say to jim dunlop " you know why your wahs don't sound good? - your inductor has the wrong Q!" dunlop replied, "well, these cost me 40 cents each, the better inductors are a dollr-forty five". ( as told to me by ken on the phone in 2002).

this is transition era stuff, dunlop was looking for ways to lower cost. they even instructed clarostat / AB to make the pot shaft AND bushing shorter. note how the potshaft does not extend beyond gear, and the nut is nearly at end of threads despite skinny washers.  by 92/93 or so they had reverted to 70s era shaft and bushing length.

pictured wah would have been mid 80s. i guess you would find an 85 thru 87 date code on the pot.

with an inductor change, these can sound really good. everything else sounds pretty good.

goodrat, agree, the key to good wah tone for me is getting a nice balance between input r and Q1 gain , they each have their own flavor when turned up. and like you said, an output boost or buffer helps. dunlop has an output buffer in circ at all times at end of bonamassa wah to preserve high end while using only 50% of the pot's r range.

[Goodrat]

The pot has a number of 8805 if that is a 1988 date.
Here is the output when the input is 500mVrms, pedal forward, frequency at highest output, which is possible on a guitar.
Notice the distortion:
http://www.rickviola.com/images/CbabyWav.JPG

[joegagan]

yes, 5th week of 88.
interesting graph.

[Goodrat]

I have to turn down the input below about 220mVrms to see no obvious distortion on the output,
which is around light to medium strumming level single coil. That is just not right.
(New scope. $329 for 100 MHz, usb file saving.)

[kingswayguitar]

I have to turn down the input below about 220mVrms to see no obvious distortion on the output,
which is around light to medium strumming level single coil. That is just not right.
(New scope. $329 for 100 MHz, usb file saving.)

jealous

[Goodrat]

My inherited Tektronix 2235A died and stunk up the house, so it's an early X-mas present
So I tinkered with the last buffer stage of my rev E Cry Baby PCB.
First of all to get rid of any distortion on the first transistor, I raise the emitter resistor to 1.3K. I have a trimmer there.
On the last op amp buffer, I had to lift a pin (not easy), add a feedback resistor, a cap and resistor to ground from the inverting input (basic non-inverting amp),
all with micro grabber jumpers. A gain of 2 is all that is needed to replace the gain lost in the Q1 emitter resistor increase.
I wasn't able to play it with the fragile connections, but it looks good on the scope, no unwanted clipping.
I'll find a neater way to do this and report back.
"If it ain't broke, it hasn't been modded enough", someone used to say.

OK, I tried it while playing with the New model Crybaby (rev E pc board) changes. Q1 emitter at 1.3K,  no lower.
Last buffer op amp with 5K feedback (pin 1 to 2) and a 5K in series with a 0.1uF to ground on pin 2.
That's a gain of two with lower corner of 318 Hz, but there is a 3.4KHz HP in front of it anyway.
Too much more gain than 2 may hit the rails.
I also had to change the feedback resistor at the Q1 base back to 1.5k or the lower frequencies may distort.
Everything is critical now. I need to find an easier way.

[joegagan]

good report.

i also find when simming wahs in spice that the interactivity of all the parts and pieces is very interesting. i liken it to the old star trek triple board chess game.  everything affects everything & one change causes a domino effect.

[Goodrat]

I can't seem to tweak values to center the clipping. If I drive with near 500mvrms, the top peak always distorts first.
If I reduce gain with Q1 emitter resistor to prevent that, it is just a little too low on the final output. I tried the collector resistor on Q1. with No success.
I increased R18 to 100K and this helps, but it still distorts on the top half a bit and I need a little more output.
I'm working on this model:

http://www.rickviola.com/images/GBC95FrevB.jpg

[PRR]

> I need a little more output.

Either or both halves of U2 can be wired for gain.

FWIW- the boost due to C12 appears to be supersonic.

Your transistor symbols are PNP but this is surely wired for NPN?

[Goodrat]

Ooops, yes, NPN. I'll fix that tonight.
If I boost before Q1, I will over drive.
With U2 I can get a little, but after 2X gain there, that op amp hits its rails.
No head room available.
OK, drawing fixed.

[zombiwoof]

Just to clarify:  Is this an early Dunlop wah, or a late Thomas Organ wah?.  Maybe an early Dunlop using leftover Thomas Organ case and boards?.  I have never seen those "greenie" caps in a CryBaby.  Also, what type of transistors are in this unit?.  Dunlop has been using those high gain MSA18 transistors for a long time in their wahs, I think that's another reason the standard CryBaby's don't sound like the older Vox/CryBaby wahs, which used lower gain transistors.  I believe Dunlop tried to compensate for the high gain transistors by changing a couple of component values.

Thanks,
Al

[wavley]

Just to clarify:  Is this an early Dunlop wah, or a late Thomas Organ wah?.  Maybe an early Dunlop using leftover Thomas Organ case and boards?.  I have never seen those "greenie" caps in a CryBaby.  Also, what type of transistors are in this unit?.  Dunlop has been using those high gain MSA18 transistors for a long time in their wahs, I think that's another reason the standard CryBaby's don't sound like the older Vox/CryBaby wahs, which used lower gain transistors.  I believe Dunlop tried to compensate for the high gain transistors by changing a couple of component values.

Thanks,
Al

I have one from the 80's and it has greenie caps, that cheap pot, and an even cheaper inductor.  It's the reason that for years I hated wah pedals because it was my first one and it always sounded terrible.  I have a Thomas Organ one that I did some mods to and it changed my mind.  The other shell is waiting to be gutted to make either the Univibe in a Crybaby Shell or something else fun.

Hey look, I found one kinda like mine!  Mine doesn't have the external power, has a brown pcb, and greenie caps, so it's like a mix of these two pedals.

This is my 80's Dunlop Cry Baby.  It was purchased brand new and right now it is all original.  Use of this blue inductor couldn't have been very popular because have not seen any information on this type of inductor on the web.  I never really got the sound I wanted out of the pedal and it has been shelved for decades.  With all the information out there on pedal modification, I wanted to see if I could get some better mojo out of this pedal.  I got an ArielFX halo, "blue" 3PDT switch for true bypass, and a "black top" Pro Pot for what I consider to be necessary replacement parts.  The halo for better vocal quality, 3PDT for better bypassed tone, and the Pro Pot to get rid of the scratchy old pot and for better vocal sweep.  Since I will need to relocate the 33k resistor (located just above the blue inductor), I will probably replace it with a 47k to further enhance vocal quality.  Of course I will test after each mod but if I'm not happy at that point I will try some additional mods.  68k input resistor to a 47k (volume boost), the 470 ohm resistor to a 300 ohm (for more gain), and the 1.5k resistor to a 2.2k resistor (more mids and smooths out bass/treble transition).  I am also going to shave the bumper at the back of the pedal for more sweep when the pedal is rocked all the way back and adjust the pinion gear to what my ear likes for the sweet spot.  We'll see how all that goes...LOL 

[joegagan]

Just to clarify:  Is this an early Dunlop wah, or a late Thomas Organ wah?.  Maybe an early Dunlop using leftover Thomas Organ case and boards?.  I have never seen those "greenie" caps in a CryBaby.  Also, what type of transistors are in this unit?.  Dunlop has been using those high gain MSA18 transistors for a long time in their wahs, I think that's another reason the standard CryBaby's don't sound like the older Vox/CryBaby wahs, which used lower gain transistors.  I believe Dunlop tried to compensate for the high gain transistors by changing a couple of component values.

Thanks,
Al

that is an early dunlop board. there was an era where they used the same supplier as the thomas boards, then they switched , it was right around this era.  the picture is the first terminal clip style i think, but the layout underneath matches the old thomas layout. initially, dunlop used up an existing stock of thomas boards, i have seen that as well. these all have SOD inductors as far as i have seen.


i agree, also the 390 ohm R to ground at Q1 was raised if i recall, as a way to make the modern mpsas sound less gainy.

a review of the progression as i recall it
1. first dunlop crybabies used thomas boards and wiring style, including SOD inductors. whereas thomas would use alternately a mix of tdk and SOD inductors ( 70 - 80% TDK approximately). i have a theory that when dunlop bought thomas from the whirlpool corp, there was a large stash of SODs that came with the acquired parts.
2. first dunlop design PCB retained the thomas layout and manufacturer, but now with term clip wiring provision. SODs still appear on these, ( i think). first appearance of power supply jacks, a 1/8" jack that was somewhat standard in the late 70s, / 80s.
3. same board style as above, but now the inductor is the small, poor sounding unit seen in the picture here 3/8" dia, 1/2" tall
4.  new boards followed, getting further and further away from the thomas layout
the green caps are common in the era pictured. the 5117 trans lasted a few years into the dunlop era.

the hotpotz1 , mexico made by clarostat but also sometimes marked allen bradley ( claro had acquired  AB by this time*), was started around 84 or 85. earliest date code i have seen on a HP1 is 85.
* note, clarostat acquired AB pot division, allen bradley continues as itself for a lot of other products they make.

[Goodrat]

To clarify, the initial post was about the older 80's Crybaby I got hold of, then I was talking about my new one (Classic bought a week ago) and how to reduce the distortion on the input. The X-sistors in the old one had the Thomas number on them "5117" which does nor correspond to a 2N number I discovered after research.

[PRR]

> If I boost before Q1, I will over drive.

That's why I saud "U2".

> With U2 I can get a little, but after 2X gain there, that op amp hits its rails.

So 3V peak is not enough??

[zombiwoof]

Just to clarify:  Is this an early Dunlop wah, or a late Thomas Organ wah?.  Maybe an early Dunlop using leftover Thomas Organ case and boards?.  I have never seen those "greenie" caps in a CryBaby.  Also, what type of transistors are in this unit?.  Dunlop has been using those high gain MSA18 transistors for a long time in their wahs, I think that's another reason the standard CryBaby's don't sound like the older Vox/CryBaby wahs, which used lower gain transistors.  I believe Dunlop tried to compensate for the high gain transistors by changing a couple of component values.

Thanks,
Al

that is an early dunlop board. there was an era where they used the same supplier as the thomas boards, then they switched , it was right around this era.  the picture is the first terminal clip style i think, but the layout underneath matches the old thomas layout. initially, dunlop used up an existing stock of thomas boards, i have seen that as well. these all have SOD inductors as far as i have seen.


i agree, also the 390 ohm R to ground at Q1 was raised if i recall, as a way to make the modern mpsas sound less gainy.

a review of the progression as i recall it
1. first dunlop crybabies used thomas boards and wiring style, including SOD inductors. whereas thomas would use alternately a mix of tdk and SOD inductors ( 70 - 80% TDK approximately). i have a theory that when dunlop bought thomas from the whirlpool corp, there was a large stash of SODs that came with the acquired parts.
2. first dunlop design PCB retained the thomas layout and manufacturer, but now with term clip wiring provision. SODs still appear on these, ( i think). first appearance of power supply jacks, a 1/8" jack that was somewhat standard in the late 70s, / 80s.
3. same board style as above, but now the inductor is the small, poor sounding unit seen in the picture here 3/8" dia, 1/2" tall
4.  new boards followed, getting further and further away from the thomas layout
the green caps are common in the era pictured. the 5117 trans lasted a few years into the dunlop era.

the hotpotz1 , mexico made by clarostat but also sometimes marked allen bradley ( claro had acquired  AB by this time*), was started around 84 or 85. earliest date code i have seen on a HP1 is 85.
* note, clarostat acquired AB pot division, allen bradley continues as itself for a lot of other products they make.

Good info, Joe.  I remember that years ago I had an early Dunlop Cry Baby that developed some kind of problem, and I sent it to Dunlop to be fixed.  It came back with the separate wired jacks and board replaced with the assembly that had the board-mounted jacks.  They told me it made the pedal "less noisy".  I was skeptical about the change, but I ended up selling that pedal later anyway.  It always seemed to me that the as Dunlop made subsequent changes to the construction, and got further away from the Thomas circuit, the worse the Cry Baby's sounded.  The Dunlop-made Vox 847 was a little better, but still had the high gain MPSA18 transistors and needed some mods to get the older Vox sound.  I still have that Vox, which has gone through several mods, but I don't use it much anymore, my main wah at the moment is a BBE, which I like pretty much out of the box.  It sounds a lot closer to my old original Clyde McCoy wah that I had when I was a kid, and later sold (for not much money!) when wah went out of fashion for some years.  Anyway, thanks for the info.

Al

[joegagan]

agree, the 2 trans dunlop made vox were good , however they used the same hotpotz1 & 2 as the cb, with its fast ramp taper. what kind of taper does the bbe have?

[Goodrat]

Yeah Paul, I suppose a small 2x boost at U2 should be enough. I will try that again. I got a tiny 5.1K SMD resistor to stick between pins 1 and 2  then I'll place another in seies with a 1uF cap from 2 to ground. I have to cut the trace between pins 1 and 2 though  because lifting an IC  pin  is too fragile.
With the wah only having the shifting narrow band, it is perceived as lower volume so you need the right amount of volume after to compensate.
(Obvious, but just thinking out loud.)