Most noisy capacitor/PCB ?

[Jaunedeau]

I just saw EEVlog #885 video, where Dave replace some ceramic smd cap to greatly reduce the humming from a multimeter.

What if you want maximum sound emited from your capacitors ? Let's say I want to play the emperor's march not using brushless motors one a floppy drive / cnc, but I juste want the acoustic noise from the circuit to sound familiar and loud ?

-Which are the more noisy capacitor I can find ?
-Should I use different size / capacity for each different note ? OR maybe one for treble, one for mid, one for bass ?
-I noticed that the caps don't emit sound when aire soldered to thin wires. I guess the PCB acts as a guitar's soundboard (and maybe some other effect occures ?). What should be the best thickness for pcb ? (thiner = noisyer ?) What would be the most noisy pcb shape ? (maybe you need to have a small tab with a resonati frequency equal to the note you want the cap to produce, then a larger pad to transmit pcb vibration to air ?)

treg.

[radar_macgyver]

I would think they'd be Y5V or Z5U ceramics. These exhibit microphonics (tap them and they'll produce a voltage) so the opposite would be true as well.

As for the PCB, perhaps a slot cutout on three sides with the cap in the middle? Size the cutout to match the frequency of interest. Have more than one, with different sizes for bass/treble?

Would make a great easter egg to have your board sing to you

[Jaunedeau]

I found a doc saying that :

-Putting the cap in the center generates more noise
-Lower voltage capacitor are noisyer
-Putting 3 caps in parallal generated +14db sound
-Thiner PCB means more noise

I now need to find long white, short white, and short black capacitor to make some keyboard shaped layout. Why don't mouser allow to search by color ?

[Stonent]

Might be fun to hard wire an SMT cap to the end of some coax and do some frequency domain analysis on it by stimulating it with perhaps a piezo transducer on a signal generator.

[sarepairman2]

using a capacitor as a input device seems like an interesting idea.

instead of buttons/etc you just use touch sensitive capacitors and scan for microphonics.

They will never wear out or anything, since there are no moving parts. and no sensitivity to grime and whatnot. very cheap too.