Parasit Studio - Quantum Defrakulator help? CD4013 bouncing?

[Tome]

Just finished building the quantum defrakulator and it almost works.....



Its a 3 oscillator synth circuit with oscillator 1 turning into a 4 step sequencer when the LFO switch is pressed. All the oscillators work... the sequencer doesn't and neither does the switch for that matter. The switch doesn't do anything until randomly it might engage the sequencer for one step or so then reset back to the first and stay there.

When I mess about with the CD4013 I can get some movement... if I ground (with a probe) pin 1 and 8 (they're joined with a jumper) I get it moving through one cycle of the 4 step sequencer. When I ground pin 13 is moves back and forth between seq1 and seq 4.

The rate knob doesn't do anything however if I touch the lugs on the rate and and seq1 knob then I can hear the rate/lfo.

I've tried changing/removing the 1M resistor and 100n cap connected to the switch however that didn't make any difference at all. I've been reading about the bounce issue related to the CD4013 however can't really figure it out.. I suspect that's the issue here?

Any help would be much appreciated... its sounds fantastic.. if only it work exactly as it should!


Stripboard layout

https://imgur.com/a/YucZmx1


build doc/schematic

https://www.parasitstudio.se/uploads/2/4/4/9/2449159/quantom_doc.pdf


Build photo

https://imgur.com/a/N2L81vC

[Jdansti]

I just put this one on my build list. Please post a photo showing the other side of the board and I'll check for mistakes.

BTW, what are the black and red wires on the bottom track going to?

[Tome]

Hey - thanks for the response.

Heres a pic of the other side.

https://imgur.com/undefined

Black and red wires are just connected to ground for the filter and oscillator pots.

I should say, I ve checked for continuity and it all seems good.. but you might see something I haven't

[anotherjim]

Pic of the solder side doesn't load for me. This is the one most helpful to eagle-eyed bug hunters.

The switch should be a momentary non-latching one. U3 5 & 6 form an electronic latch. Sequencer should run when U1.1 pin6 Set input is 0v and stop when 9v. C3 & R4 should cause enough time delay to prevent switch contact bounce causing it to jitter. C3 will start discharged to 0v. When the switch closes, the output pin10 is momentarily shorted to 0v by C3 and this, in turn, forces pins 12 & 11 to 9v. When the switch opens, C3 will charge to 9v via R4. This reverses the action next time the switch closes giving the required start-stop action.

Oscillator U3.1 should always be running. At the slowest rate (max pot resistance) I would expect to see the voltage on its pin switching between 0v & 9v. At the fastest rate it should read about 4.5v as the DMM won't change fast enough so shows an average between 0v and 9v.

[Tome]

This link should work:

https://imgur.com/a/77TqrFx


Yep, I'm using a non latching momentary foot switch.

Would it be useful for me to record all the voltages of the IC pins?

[Vivek]

Do your LEDs cycle ?

[Tome]

They cycle only when im grounding pin 2.. its not a steady cycle. 1-2-3-pause-4-pause then back to 1 and nothing happens.. something like that. But they do light up the corresponding oscillators work as well.

[Vivek]

If it was
1,2,3
5,6,7

Then it's Salsa !!!

[Vivek]

Does the rate of the LEDs change with the rate knob ?

[Tome]

hahaha... salsa sounds more enjoyable than figuring this out!

No, the rate knob isn't really doing anything. (unless im touching the lugs .. then I can hear the rate change but has not effect ton the LEDs)

[Vivek]

That would possibly mean that the error lies in the LFO part

To prove that analogue switch onwards works

You could disconnect A and B  from the LFO

And apply 0 or 1 to A and B with wires to ground and Vcc

And check if you can get 4 different sounds from the Analogue switch

Once that's proven to work, we can debug the flip flops

[anotherjim]

It would be worth recording the voltages. Logic is logical. An inverter should always have an output level the opposite of its input.
A worry is the CLR resistor for the LED's. If this is too low value, too much current will flow in the 4053 chip. If you have ordinary 20mA LED's, the CLR can't be much lower than 6k8.

[Vivek]

Build Doc says

Current Limiting Resistor for the sequencer LED's. They share a
single resistor since there's always just one LED engaged at the
time. Use the appropriate value for your LED type. I recommend
using a 4.7K resistor for a diffused LED or a 15K resistor for a clear
superbright LED.

Vcc is 9V
Hence that would be low current maybe around 1.3mA for diffused LED



If you had 20mA going through a 6k8 CLR, the voltage drop on that resistor could be fairly substantial.

[duck_arse]

we can't see the led. or the switch. or any of the pots. we need all, just in case.

[anotherjim]

Use the appropriate value for your LED type

The first online guide I found wants 330R for standard red LED's at 9v. The chip spec says 10mA max.

[Tome]

Good morning!  and thank you for your input...

So, I'll get around to recording and posting IC's reading in the next couple of hours.


Regarding the LED - I am using these: https://www.taydaelectronics.com/leds/round-leds/5mm-leds/led-5mm-orange-water-clear-super-bright.html


I tried changing the CLR LED.. it was 4k7 and I upped it to 15k and then 20k... all of a sudden it started working more like it should. the momentary switch was triggering the sequencer and the rate knob was effecting the speed!! ... then I moved the circuit and it all stopped and is again sporadic although less so.

So, some progress that's for sure! any thoughts..?

more pics:


https://imgur.com/9uGLfi8

https://imgur.com/2lYHHzJ

https://imgur.com/vxSAAWv

https://imgur.com/48UaFda



IC READINGS

IC1 CD4013

1:    8.5
2:   0
3:   .13
4:   0
5:   0
6:   0
7:   0
8:   0
9:   8.5
10:   0
11:   0 -8.5 cycling
12:   0
13:   8.5
14:   8.5



IC2 CD4052

1:   .05   
2:   .08
3:   1.8
4:   1.8
5:   .06
6:   0
7:   0
8:   0
9:   8.58
10:   8.58
11:   3.95
12:   3.95
13:   3.95
14:   3.95
15:   3.95
16:   8.5


IC3 40106

1:    0
2:   8.5
3:   8.5
4:   0
5:   3.30 - 4.60 cycling
6:   0 - 8.5 cycling
7:   0
8:   3.95
9:   3.95
10:   3.95
11:   3.95
12:   3.95
13:   3.95
14:   8.5

[anotherjim]

4013.
Pin3 should be same as pin11. Are they linked ok? I suspect pin3 has no connection.

[Tome]

4013.
Pin3 should be same as pin11. Are they linked ok? I suspect pin3 has no connection.

Wow! You might be absolutely right!! That jumper isn't connected at the top! Column 2 row 7

[Tome]

Despite looking over everything a thousand times I managed to miss an unsoldered jumper end... can't believe it! Thank you everyone for your input... truly an amazing community. 

[Vivek]

4013.
Pin3 should be same as pin11. Are they linked ok? I suspect pin3 has no connection.

Excellent catch, Jim !!!

Respects !!!