Hi There (again) ,

- Back to this 52uf cap question. ( After a couple of years )

- Here's a link to a place that consistently sells these MPP caps in oil ( that I previously mentioned above ). Click Here !!!

- I'd recommend buying the listed 40 uf /370 volt , Sprague Motor-Run for use a base cap . At less than $5.00 a piece ( before taxes or shipping ) it's really hard to go wrong in buying a couple ( to at least play about with ) .

- I'd then follow Gordons' advice from above but implementing a hybrid version of it. That means I would add a 10uf Dayton MPP ( dry film ) on top of the 40 uf motor run and then another higher quality 2 uf Film & Foil Polypropylene sort ontop of this mix to make up the desired 52 uf value. So far IME, the smoothness of Polystyrenes bypass caps are somewhat "lost" in coned speakers of that size ( 10" ) so I would use the .01 uf Audio Thetas from RelCap / these have quite a following at this forum ( though I haven't yet tried them ).

- Another "wrinkle" to this would be to DC bias ( Charge Couple ™ ) just that additional 12uf of capacitance (that sits on the 40 uf oiler ). I'm doing this right now in my horn circuit. The DC biasing works very well on the dry films and somewhat less so on the "wet" films . ( I presently run one horn circuit completely biased with the other having just the dry film biased ) . It's difficult to impossible to make out a difference between these two approaches. If DC biasing the 12 uf , I would first try 2 , 24 uf Solen paralled across the 40 uf oiler . IMO, Solens' are cheap enough to buy as an initial investment in the search for the perfect mix of caps. I've found that the Solens' will "mix" quite nicely with a wet MPP cap type when the Solens are DC biased. ( MPP = Metallized Polypropylene ) ( wet = oil immersion )


- To learn some more about DC biasing ( and Bypassing ) CLICK HERE !