Also, I found this. Seems relevant given that the alleged benefit of charge coupling of caps is related (I think) to dielectric absorption.
Capacitor Characteristics - what do they mean for audio applications? Are 'audiophile' grade caps worth the extra?
sound-au.com
Don't know haw to link it directly, but from the above web site (quoted as fair use in scientific context):
"I only heard about 'charge coupling' fairly recently, although it's apparently been around for a while. This is best described as a complete crock, and it doesn't stand up to even the most rudimentary scrutiny. Yes, the 9V battery will last for its shelf life (there's no current drawn other than a tiny leakage), but it's simply a waste of parts and a battery. We all
know that the battery will eventually leak its essential fluids (which are corrosive). It's not shown, but a single 9V battery can 'charge' multiple different caps within a crossover network via additional 1MΩ resistors.
I must confess that this has to be one of the
most pointless exercises I have ever seen, even though there is no end to other pointless exercises in audio. The needless increase of parts (and cost) will never provide an audible 'improvement' in a double-blind test, although there
might be a small audible difference because of the extra capacitance (due to the 'bypass' caps) which will change the crossover frequency slightly."
He's Australian and I wasn't that harsh. But the language taken aside, I agree. Dielectric absorption isn't an issue if the circiut is low impedance, as he said. Please keep in mind that even electrolytics are useful if a) not overloaded current wise and b) used as the symmetric bipolar variant. I never had any problems with even super old specimen of trustworthy pedigree, but that's anecdotal.
