# Schadenfreude wants to tap, tap, tap



## jeffwhitfield (Aug 21, 2022)

Hey folks, just finished a Schadenfreude a few days ago. I think it's working...but I'm getting a weird tap from it whenever it's engaged and I'm not playing. It's at a rhythm of ever 2 seconds and appears to be coming from the CD4046BE. I switched it out and it doesn't seem to fix it. Could it be I'm using the wrong CD4046? Or maybe the 100n film caps I'm using need to be changed out? Thx in advance.


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## Chuck D. Bones (Aug 21, 2022)

_Build Docs Coming Soon..._


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## fig (Aug 21, 2022)

Chuck D. Bones said:


> _Build Docs Coming Soon..._


That large tantalum appears to be between INTENSITY and GND. Could the tap ( ~1Hz ) be due to poor filtering? Just showing off my well-versed ignorance here. Feel free to cite Bill’s law.


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## Chuck D. Bones (Aug 21, 2022)

Until there are some build docs, I'm unable to assist.


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## Robert (Aug 21, 2022)

https://docs.pedalpcb.com/project/Schematic-Schadenfreude.png

It might be worth attempting to ground the unused inputs of the CD4049.... they were not grounded in the original, so they are not here, but that doesn't make it "right"...    You could pull the 4049 and see if it stops, if it doesn't, that's not the issue.

This is a crude circuit, I'm not particularly fond of the Tone control....


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## Chuck D. Bones (Aug 21, 2022)

"Crude" doesn't begin to describe it.  

Does the ticking change when you turn the SPEED or INTENSITY controls?


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## jeffwhitfield (Aug 21, 2022)

fig said:


> That large tantalum appears to be between INTENSITY and GND. Could the tap ( ~1Hz ) be due to poor filtering? Just showing off my well-versed ignorance here. Feel free to cite Bill’s law.


That's a damn good suggestion.


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## jeffwhitfield (Aug 21, 2022)

Chuck D. Bones said:


> "Crude" doesn't begin to describe it.
> 
> Does the ticking change when you turn the SPEED or INTENSITY controls?


Nope. Speed and Intensity has no effect.

I'll look into Robert's suggestion on the grounding of unused inputs. Makes sense if it's some internal issue with the 4046.

I'll also try Fig's suggestion...or at least investigate...cause you never know. Damn tantalum could very well cause something like this. Then again, if that was the case, then the tapping would occur before things even hit the CD4046. That is unless it's some jacked up filtering that only effects the CD4046. I'm not an engineer so I'm talking out my ass. 

Heh..."crude". That's funny, right there.


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## Robert (Aug 21, 2022)

Pull the 4049 first,  that'll save you some trouble if the ticking doesn't go away.


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## Nic (Aug 21, 2022)

4049 and 4046 are similar?

Doc says 4046, so I guess this is no problem

Now feeling dumb seeing those two are present ,  just ignore me!


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## Feral Feline (Aug 21, 2022)

Wowskers!

You've got one of them thar $50 silicon mauve thingers.

You like to mauve it mauve it, you like to mauve it mauve it, you like to...

MAUVE IT!



Subbed, in case I can learn something riding the coattails of others.


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## jeffwhitfield (Aug 23, 2022)

Ok, so here's what I discovered...

I pulled the 4049 and didn't hear any taps. I also switched out C1 and C9, which resulted in a significant reduction in the timing between the taps. The taps are audible only on the left side of the 4046 (pins 2, 4, 6, & 7). 

Only thing I can surmise is that the run of 4046's I got might be defective. Might try another one from a different vendor just for grins.

Granted, this is a "crude" circuit so could very well be that it's sensitive to the 4046 and caps used. If I turn on my noise gate with it I can make the taps go away easily so, while it's a bit annoying, it's not unusable. Gonna mark this one as "solved" for now. At the very least, this will let other builders know this could be an issue with this particular circuit.


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## Robert (Aug 23, 2022)

I'll dig out my prototype and see if I hear anything like this.


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## fig (Aug 23, 2022)

jeffwhitfield said:


> Then again, if that was the case, then the tapping would occur before things even hit the CD4046.


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## Chuck D. Bones (Aug 23, 2022)

jeffwhitfield said:


> Only thing I can surmise is that the run of 4046's I got might be defective. Might try another one from a different vendor just for grins.


CMOS is very sensitive to ESD, so *if *the 4046 is defective, it was most likely cause by ESD.  On the other hand, the design certainly has its defects... 

I'm resisting the urge to breadboard it, just to find out what it does.


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## jeffwhitfield (Aug 23, 2022)

Chuck D. Bones said:


> CMOS is very sensitive to ESD, so *if *the 4046 is defective, it was most likely cause by ESD.  On the other hand, the design certainly has its defects...
> 
> I'm resisting the urge to breadboard it, just to find out what it does.


Considering the source the 4046's came from (Tayda) I honestly wouldn't be surprised if it was ESD. I mean, Tayda is ok with most things...but I can't say with any certainty that they're all that great about how they handle ESD sensitive chips. Probably will get another set of 4046's from another vendor just for grins. 

It's a weird one for sure. The Flock (Beetronics Swarm) is a pretty weird one too. That's been my thing though lately...weird shit!


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## Chuck D. Bones (Aug 24, 2022)

I think that if pulling the 4049 causes the tapping to stop, then the problem is in the 4049 part of the circuit.  If the tapping persisted after removing the 4049, _*then *_I'd suspect the 4046.

What are you using to drive this circuit?  If you're using a guitar, does turning the guitar's Volume control affect the tapping?


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## jeffwhitfield (Aug 25, 2022)

Chuck D. Bones said:


> I think that if pulling the 4049 causes the tapping to stop, then the problem is in the 4049 part of the circuit.  If the tapping persisted after removing the 4049, _*then *_I'd suspect the 4046.
> 
> What are you using to drive this circuit?  If you're using a guitar, does turning the guitar's Volume control affect the tapping?


Definitely the 4046. Even without the 4049, you can clearly hear it pumping. Guitar volume has no effect. Happens even if it's just a loop pedal going into it followed by an Orange amp. Gonna get some 4046's with my next order for further testing. That's gotta be the problem.


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## flemming (Aug 25, 2022)

I wonder if your "tap tap" is my "tick tick" in the Super Heterodyne Receiver:






						Ticking from SuperHeterodyne Receiver
					

I've poked at this one several times now, boxed it up, unboxed, rinse, repeat and I'm finally throwing it out there to see if anyone has any tips.  This isn't the first time this has been mentioned:  https://forum.pedalpcb.com/threads/mini-heterodyne-receiver.462/post-2722  The ticking only...




					forum.pedalpcb.com
				




Does it sound like this?


__
		https://soundcloud.com/user-74207647%2Ftick%2Fs-q25YU2uUSou

Mine seems to be coming from IC6 which is a 4046 as well.  I'm sure there are a boat load of other reasons why this could be occurring, but I've been watching this thread to see if you came to any conclusions.  I too switched out the chip for one I bought directly from TI and the problem still existed.  When I last pulled it off the shelf I feel like for a brief moment the noise went away when I unplugged the input (this isn't the case so I must have been delirious at the time), so I threw a shielded input cable on it just for the hell of it and no dice.  The only thing that I've found that "fixed" it was knocking the voltage down to 8v.


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## jeffwhitfield (Aug 26, 2022)

flemming said:


> I wonder if your "tap tap" is my "tick tick" in the Super Heterodyne Receiver:
> 
> 
> 
> ...


Interesting. It does seem similar. Mine is a much, much slower tick/tap...like a good 2-3 seconds apart. It slowed when I switched out the caps around it. I'm wondering if maybe adding a resistor inline on the leg that powers the chip will help...basically taking down the voltage enough to remove the tick/tap.


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## jeffwhitfield (Aug 21, 2022)

Hey folks, just finished a Schadenfreude a few days ago. I think it's working...but I'm getting a weird tap from it whenever it's engaged and I'm not playing. It's at a rhythm of ever 2 seconds and appears to be coming from the CD4046BE. I switched it out and it doesn't seem to fix it. Could it be I'm using the wrong CD4046? Or maybe the 100n film caps I'm using need to be changed out? Thx in advance.


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## Chuck D. Bones (Aug 26, 2022)

Have you tried a different power supply?  I have a 9V PS that does not like powering 4049s running in linear mode.  

A 1K resistor in series with the power (downstream from the LED) might just fix it.  I think running CMOS in linear mode on 9V is a bad idea.  I get less current draw and more gain by reducing the Vcc.


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