Burn in Capacitor phenomena


Hello,

I just wanted to post about something I've just experienced with burning capacitors and a theory on a contributing reason to why they may sound different with time on them.

I made a capacitor burn in rig that play's music through the capacitors for burn in. During startup of this rig I noticed as the electric pulses of music pass through the capacitors they vibrate. That is you can hear the capacitors playing music. Over time I've noticed the volume or vibrational amplitude seems to have gotten slightly smaller. I am just throwing this out there, but my hypothesis is; that as electricity passes through, there is heating and swelling of the parts, the parts then undergo greater pressures and a greater sense of malleability and stickyness for a lack of a better word. These parts begin to Stick together and oils or plastics begin to settle into imperfections in the surface of the foils, ie: the parts meld causing a less ressonant (or perhaps a coupled resonance allowing the capacitor to resonate as a whole) sum of parts.

Why else would the capacitor become percievably less quieter? Other than a drop in frequency or less resonant.
perhaps because it's burning out, haha, I hope not.

Anyway I notice a difference in capacitor sound quality with time, and typically it sounds better as a less resonant capacitor probably would.

Thoughts?
scutterflux
microphonic caps? new one on me. I have seen i on guitar amp tubes and some pedals but not on discrete components. that aside it seems risky to assume the nature of sound from a cap is linked to the sound of the system they are installed in. Sounds like your burn in rig is driving the crap out of those caps and likely just burning them up.
Agree with Paulsax. They become microphonic when they are about to die.
Had to replace many in my 30 years old preamp.
All caps are apparently microphonic. That's why those tiny little 3 mm (contrained layer) VTS dots from Marigo when stuck onto the tops of all caps improve the sound.

Cheers
Caps vibrate to the music. I can't say that I have heard them play music but they do vibrate. This topic was discussed when I worked at Westlake Audio and the owner took this into consideration when he chose caps for his products.
The better sounding/quality capacitors do seem built to address the issue of resonance and they are better damped.
Duelund is a prime example of high effort to minimize resonance.
Regards,