SOLVED Super Heterodyne Receiver clicking sound

[GanjaBlitz]

Hi guys,
I recently started doing my first few project. Ordered a few pcb and completed 5 pedal for now. I got super confident as all of previous project were made without a single problem. I was keeping this board for later to make sure I got a better understanding of the assembly process so I started this one last week. I can only do these on spare time so I'm working very slow but eventually got everything soldered.

When I tested it at first I had absolutly no sound. Rechecked everything and had to resolder a few cold joints. The second time I just had a ticking sound without anything else so I rechecked and missed another cold joint. Now the pedal is "working", every function act as supposed but no matter the knob I turn I get a sort of clicking//ticking sound that is not intended compared to the data corrupter. My assumption is now that something is wrong with the TL072, CD4046 or CD40106. I have very limited knowledge about ICs in general so I'm kind of not sure where to look at and since I'm a newbie at this I'm ready to learn some more.

Thanks in advance!

 

[Nostradoomus]

would you say it is heterodyning?

 

[jwin615]

would you say it is heterodyning?

Most definitely.

 

[giovanni]

I still see a few solder joints that may be a bit cold. Some look like big “blobs” which often means they haven’t flowed enough and/or they have a bit too much solder. That may or may not fix the ticking. Also, if you haven’t already, double check all component values (visually).

Finally, I haven’t had any issue with ticking on my build but this is a pretty noisy pedal. Does anything change if you move the wires around? I am not sure which chip produces the LFO, I would need to study the schematic a bit more than I have.

 

[jwin615]

Do the root or glide switches change the ticking, either in audible frequency or rate?
Any other controls make it better or worse?
Also, cmos chips are particularly sensitive to ESD so use proper precautions.

 

[GanjaBlitz]

I still see a few solder joints that may be a bit cold. Some look like big “blobs” which often means they haven’t flowed enough and/or they have a bit too much solder. That may or may not fix the ticking. Also, if you haven’t already, double check all component values (visually).

Finally, I haven’t had any issue with ticking on my build but this is a pretty noisy pedal. Does anything change if you move the wires around? I am not sure which chip produces the LFO, I would need to study the schematic a bit more than I have.

I did double checked values but maybe something specific is not working properly since there might be cold joint left so i'll recheck that to make sure. Also moving wire doesnt change anything or make anything worse but ill check and make sure solder joint are not cold also just in case. Im unsure too about the LFO but i'll try to get some data on the ics to confirm the ic and double/triple check joint for that specific socket. Maybe try to reflow if needed also.

 

[GanjaBlitz]

Do the root or glide switches change the ticking, either in audible frequency or rate?
Any other controls make it better or worse?
Also, cmos chips are particularly sensitive to ESD so use proper precautions.

The root switch on the oscillator side seem to make the clicking go at different rate if I remember correctly ill validate when I get home, but maybe the 4046 or 4024 could be in cause with the cold joint or blob mentioned by @giovanni . When you says "sensitive to ESD so use proper precaution" ,is it in the sense of when I manipulate the IC ?

 

[giovanni]

The root switch on the oscillator side seem to make the clicking go at different rate if I remember correctly ill validate when I get home, but maybe the 4046 or 4024 could be in cause with the cold joint or blob mentioned by @giovanni . When you says "sensitive to ESD so use proper precaution" ,is it in the sense of when I manipulate the IC ?

Yeah, when you handle the ICs, be careful. I don't think your ICs are cooked based on what you are describing but they are a bit more delicate than others.

 

[GanjaBlitz]

@giovanni , it seems you were right about the blobs. Did reflow on these and on every chip and works perfectly , also no more ticking. Pretty happy with the build, will try to design all original graphics for next set of build I do, these first few ones allowed me to get comfortable with the whole design, part ordering and assembly process.Thank all for the suggestions.