Super Heterodyne - Divebomb sound with no input

[airbud]

Hi all, just finished this about an hour ago after the delivery was delayed due to the big storm in the northeast. While I'm playing it sounds cool and I believe is working correctly, but if I don't play or even unplug the input, it'll make a kind of divebomb sound falling in pitch, like a whammy bar dive.

I tried a different opamp and CD4069 (based on another thread I had some intuition it might've been those), and checked the soldering on both those two spots specifically (the last two pics) and overall. I didn't see anything that screamed out at me, any thoughts on what to try next?

The sound reminds me of when I had GI Joe's as a kid, and some made crappy little noises designed to annoy parents, and this one was the divebomb noise.

Thanks for any advice!

 

[airbud]

Hey airbud,

I also built the heterodyne receiver, and have a similar sound that I could describe as a "divebomby" video game kind of sound, but I think it's just part of the pedal/settings.

I know this because you can get the same effect in the flock/swarm and delaying the tracking (rightmost knob, CW). I think it is taking the input and harmonizing with it/octaving. When the input stops, it takes a while for the pedal to catch up from where it was at the input note as it tracks down to zero, so it gives you the video game diouuuuuu u u sound. Is that what you're talking about?

If it is, thats just my uneducated guess.

yeah that's the sound, and it's definitely something along those lines, but it makes the noise even when no input is connected (or the guitar is muted). it's constantly starting from one pitch, going down to an almost inaudible frequency then goes back up to the starting pitch.

my hypothesis is some noise is going into the CD4069, which in my understanding takes the input voltage and turns it into an oscillator. at this point I think the batch of chips is causing the noise, so I'm going to order some NOS chips soon.

 

[comradehoser]

Is it across all settings?

The key to mine is the rate knob at the bottom. If it's set CCW, it divebombs, CW, not (although there are still plenty of glitchy artifacts). Seems to act the same in reverse as the "tracking" setting on the Flock.

 

[airbud]

Is it across all settings?

The key to mine is the rate knob at the bottom. If it's set CCW, it divebombs, CW, not (although there are still plenty of glitchy artifacts). Seems to act the same in reverse as the "tracking" setting on the Flock.

ah ok, I'll experiment a bit more when I'm back home. I got very fixated on analyzing the circuit itself early on so I may just not have played with the knobs enough.

one of the most frustrating/challenging aspects of this hobby has been knowing "is this supposed to sound like this or is it broken?" I question my soldering, whether I got the right component values, if the parts I sourced are duds and sometimes it's just "oh yeah don't go past 3 o'clock on the bingbong knob or you'll break your eardrums."

 

[comradehoser]

Believe me, my dude, I feel you on that one, 100%

Best thing for me is to go check out some demo videos and see if the pedal matches, more or less.