Little Angel problem

[bluebunny]

When I got back into this lark about five years ago I bought a "starter compendium" of mixed poly caps.  I was had - they were clearly offloading.  Nothing smaller than 100nF.  Amongst the monster haul I have a bunch of 4u7 (yes, 4u7) film caps the size of a small desk.   

[Kipper4]

  Amongst the monster haul I have a bunch of 4u7 (yes, 4u7) film caps the size of a small desk.   
[/quote

You and me both Marc....

[duck_arse]

First time I bought green poly I didn't know how much them were big so I bought a pair of 470nF, just for try it. Huge! Never used them, I still have it. 

wire them on tagboard, or point-to-point, call it mojo. for added points - tell people they are the hard to find ones with a 20% tolerance on the mojo (most of us have to make do with 10%, sometimes as low as 5% mojo).

what are you doing to that lark, blue?

[vigilante397]

I have a bunch of 4u7 (yes, 4u7) film caps the size of a small desk.   

Pics?

[Elijah-Baley]

[...] indeed I have on my list the zombie chorus, ready to build.
[...]

Indeed I built it. Indeed it WORKS at first attempt.
I used the tagboard layout. It has a chorus/Vibe switch, (the Vibe mode I don't like too much at slow speed, but I don't care), and a three way modes switch. Some mode are a bit noiser than other, but it's ok.
I have a chorus , maybe not THE chorus, but it sounds nice to me.

Just an issue, I have a little tick noise. But also I have to say I have the resistor for the led on the board, but stil no connected to the led. It is a hint? Because if I touch the lug of the Rate pot the volume of the tick raise up. Something to do with ground or whatever?

[bluebunny]

I have a bunch of 4u7 (yes, 4u7) film caps the size of a small desk.   

Pics?

The cap is on the left.  That's most of the UK on the right.  So you can see it's pretty big.   

[Elijah-Baley]

[...] indeed I have on my list the zombie chorus, ready to build.
[...]

Indeed I built it. Indeed it WORKS at first attempt.
I used the tagboard layout. It has a chorus/Vibe switch, (the Vibe mode I don't like too much at slow speed, but I don't care), and a three way modes switch. Some mode are a bit noiser than other, but it's ok.
I have a chorus , maybe not THE chorus, but it sounds nice to me.

Just an issue, I have a little tick noise. But also I have to say I have the resistor for the led on the board, but stil no connected to the led. It is a hint? Because if I touch the lug of the Rate pot the volume of the tick raise up. Something to do with ground or whatever?

I soldered the led. Positive from the board and its negative with the ground.
I can hear the ticking noise, especially with high volume of my amp and more than else with high rate and high depth settings. Seems to me there's no mistake on the board. Is it just like that?
Thanks!

[Cozybuilder]

[...] indeed I have on my list the zombie chorus, ready to build.
[...]

Indeed I built it. Indeed it WORKS at first attempt.
I used the tagboard layout. It has a chorus/Vibe switch, (the Vibe mode I don't like too much at slow speed, but I don't care), and a three way modes switch. Some mode are a bit noiser than other, but it's ok.
I have a chorus , maybe not THE chorus, but it sounds nice to me.

Just an issue, I have a little tick noise. But also I have to say I have the resistor for the led on the board, but stil no connected to the led. It is a hint? Because if I touch the lug of the Rate pot the volume of the tick raise up. Something to do with ground or whatever?

I soldered the led. Positive from the board and its negative with the ground.
I can hear the ticking noise, especially with high volume of my amp and more than else with high rate and high depth settings. Seems to me there's no mistake on the board. Is it just like that?
Thanks!

Elijah-
I built a Zombie Chorus, and to get rid of the ticking wound up using power filter caps right at the LFO, and a 47nF cap to ground between the flashing LED and the CLR- See the following schematic, especially U3 and Q2:

[Elijah-Baley]

Thanks a lot, Cozybuilder!
I'll give it a chance and I'll let you know.

[Elijah-Baley]

I'm looking the schematic, but is a bit different from mine.
I built this:



I should be built with an anti-tick trick. I think it should be absolutely silent, but I can hear a weak tick, nothing loud, but If the volume is high, the setting extreme, and I don't play I can hear it.

Mine doesn't have the flashing led. Should I filter my normal status led anywasy with a 47nF cap?

About your U3, on my building it have to be IC4, a TL062.
So, I need a 100pF (a simple ceramic?) and I got it. And a 22uF tantalum? Necessarily? Unfortunately I have 10uF and 47uF electrolytic . Could be ok?
If I am not wrong I can solder them: one leg on the pin 8 of my IC4 TL062, and the other leg on the stripe immediately above the first one, because that should be on the ground. Try to look the route, it is a bit long, but it should be out on the ground wire. I'm gonna check with the multimeter, anyway.
Is that all ok? Seems pretty easy. If it will work for me.

Thanks.

[Cozybuilder]

The differences I saw between your (Mark's) layout and my schematic are:
   1- Vref uses 12K to ground (mine is 15K)
   2- Vibe switch (removes 10K from circuit for vibe mode- my R5)
   3- CD4046 pins 14 & 16 are tied to +9V only, mine has additional power filtering at the chip (10uF electro + 100nF ceramic).
   4- No 10K to depth pot at CD4046 pin 9
   5- Depth & speed pot values differ
   6- I use additional  power filtering at LFO power (10uF electro + 100nF ceramic)
   7- Different LFO chips

If you don't have a flashing LED, then the 47nF between the CLR and LED won't help

For the value of the additional filter caps, I would think either your 10uF or 47uF electro with the 100n ceramic at the LFO should be fine.

You asked about tantalum vs electro- tantalum is electrolytic. You can use any electrolytic you want here- mine was a small box build and size was a consideration.
The additional power filtering is probably the biggest contributor to reducing the ticking. Separating the Vref between the I/O and LFO was the major fix, and your layout incorporates that. Now its a refinement- the additional caps.

[Elijah-Baley]

Thank you for found the differences between the schematics.

Indeed, I thought with my layout I would not have ticking problem, but I have a bit.
That filter you used could be worth. I have to try, no choices.

Update: NOT solved.
This filter in my case have no effect on the ticking. Try the 100nf ceramic cap and a 10uF, a 47uF and a 100uF electrolytic (this one was for my X-Fuzz project).

(I confused, I used a 100pf ceramic, and then my only 100nF ceramic I have. I also have a 100nF film, but I think it will no change anything, now).

With pot at max I can hear the ticking. No much usable at this condition. With medium settings no problem, the ticking become less audible or not audible at all.

And now? What about the filter on the CD4046? Could be help me?

[duck_arse]

EB - does the tikk follow the rate pot setting, or is it in some way connected to the "other" parts being oscillated? [I have no experience at all w/ the 4046.]

one drastic measure that might work is to cut the link to IC4 (I hope that's the lfo?) supply pin8 and the ground link to pin4. then run a hook-up wire FROM pin4 to where the supply ground enters the board, and another wire FROM pin8 to where the V+ supply enters the board. an even more desperate measure would be to stick a small value resistor 47R~100R ish in the line to pin8, to work with the bypassing caps.

[Elijah-Baley]

Thanks for the quote, duck_arse: [In your face PT2399!]

So, it seems a bit drastic indeed. I don't know if I understand it all.

Where the supply ground enters the board, exactly? And where the V+ supply enters the board, exactly?
If you mean to wire that two points (pin 4 and pin8) directly to the ground stripe and the 9v stripe (or ground lug and 9v lug on the DC jack) it could really be so different?
Or I wrong all?

[duck_arse]

no worries, mate.

my thinking on the dractic measures is that the supply and groun to the lfo wander all over the board, and supply the audio section as well. any current the lfo draws (thump thump thump goes the lfo) will produce a voltage drop across all that wandering resistance, however small it might be, and could then find its way into the audio stream.

so, take the lfo out of the way of the audio section, by essentially "starring" your supply. run lines to and from the lfo chip that supply nothing else, and the only way to do that is to get the supply volts where they enter the board, so as close to the wires that go to your DC jax, fer inst. so not directly to the ground stripe, but as close to directly to the supply ground wire. and supply +. yes, the jack itself would be ok, but you need to cut those links on the board.

and if I'm wrong .....

[Elijah-Baley]

Separating the Vref between the I/O and LFO was the major fix, and your layout incorporates that. Now its a refinement- the additional caps.

It should be already, don't forget. But, if I would...

...to try that mod I should cut the stripe between the pin4 of the IC4 and the jumper. Pin 4 is not grounded now. About pin 8, I think I should cut the jumper, and pin 8 doesn't go to the 9v (and even the CLR. No matter, I can put it flying on the DC jack).
I could solder the wires directly on the solder side of the board. One on the pin 4 and one on the pin 8. I'm testing the circuit with the alligator clips. Pin 4's wire will go with the ground wire of the board (and the negative of the battery snap). The pin 8's wire will go with the 9v wire.
Is that good?

[duck_arse]

Is that good?

only time will tell.

[Elijah-Baley]

I know . Just to see if I translated the idea into the layout.

[Cozybuilder]

I think Duck is right, the ground to the 12K of your Vref to the IO chip (U3) is shared with and in close proximity to the LFO ground. Heres one way to isolate the LFO ground:

For board hole ID, letters across, numbers up & down, starting at upper left corner:

1) Solder a jumper wire from D9 to C21 (clean ground to 12K & 10uF cap)
2) Make a trace cut under the 47K (G21)
3) Remove the jumper to U4 pin 4 (H17 - H21)
4) Connect IC4-pin4  to star ground (H21 to power jack or other star point)

[Elijah-Baley]

The Vref was separated, but not the ground? If I touch lug 3 and 2 of the rate pot the ticking become louder. Has it sense?

I draw it.

Seems easy, this time, too.
Thank you, guys.

If this doesn't work...