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Combining in antiparallel still halves the capacitance, no?
The use of series combinations has been suggested before (i.e. by Bateman). While this is probably even more effective in reducing distortion (essentially it lowers the AC swing seen by the capacitor) it also reduces the effectively available capacitance,
To my best knowledge I'm the first one who writes about this, despite the striking simplicity of the arrangement. Samuel
The problem with two electrolytic capacitors in antiparallel would appear to be that the combination doesn't tolerate much or any DC.
So even if the reverse bias is not large enough to make it explode, that cap won't be happy.
John Curl wrote about anti parallel caps in TAA or audio many years ago.
Perhaps the most funny application would be to use the anti-pair in micpres.
Not looking to generate more work for you, but have you considered testing the influence of DC bias?
Did you by any chance test a couple of tantalums as well?
Try a pair of caps in anti-series, + ends connected to one another, and a 1M resistor connected from the junction between them to V+.
Your measurements seem to suggest they are happier with one back biased?
Presumably there is a reason why you don't just use NP caps?
In fact I've been mostly thinking about caps in the feedback network of transformerless micpreamps; here the impedance levels are really low (approaching 1 Ohm), so series combinations ain't a practical solution. Also the addition of a servo is not as straight forward as it is for other applications. However DC offset at this place is usually less than 10 mV, so the anti-parallel arrangement should be a decent solution.Samuel
True, thanks for pointing this out. In this case it's even more surprising that this arrangement is not better known--31 years later I can't remember having seen any schematic except my own which would show it.