MMC caps: prices, sources, and types

["Tesla list" <tesla-at-pupman-dot-com>]

Original poster: pepperman-at-softhome-dot-net 

I've been trying to price an MMC, but using the recommendations I've
generally seen (e.g. 3-4x the rated voltage of your transformer) I've been
having a hard time finding a good source.  Putting that many in series to
handle the voltage tends to mean you need more strings, which
significantly drives up the price.  I noticed that the Geek Group tended to
not use as many in their MMC, and it seems to perform acceptably.

So what would you say the minimum combined DC voltage rating (as a
percent of the transformer voltage) is to have an MMC that will perform
acceptably and still have good reliability?  I'm not overvolting the
transformers on a variac, so that shouldn't be an issue.

I'm also looking for a good source for the caps.  I know the Geek Group is
generally a very good source, but my time frame doesn't allow for the
delay it would take to get caps from them (they won't get another
shipment in until 5/31).  What other sources would you recommend for
good (and cheap!) caps?  And would any type other than the metallized
polypropylene caps still be acceptable?

Finally, what would you say to expect to spend to put together an MMC
for a 1.5 kVA Tesla coil?  I'm not sure yet whether I'll be using 10 kV or 15
kV transformers, so unfortunately I can't specify.  I guess if 10kV, I'll be
trying to get 150mA, and if 15kV, I'll be trying for 90mA.

Thanks for your help!
Michael Johnson