Crossover capacitors

[Adolf Corkscrew]

Hi everyone.

I'm having trouble deciding caps for my passive OB's crossover. The problem is, that for the lower point I need about 156µF worth of capacitance for the midrange. Currently I have this bunch of odd PP caps (Solen fast, Audyn MKP QS, Obbligato) I have made the total value of. Also an Arcotronics MKP motor cap. The values range from 4,7 to 47µF. No small bypasses.

The question is this: would I be better of buying a single quality cap to make the whole 156µF, or paralleling a little smaller caps of the same quality? Has anyone had any first hand experience on the difference here? eg. 155µF Clarity Cap ESA would do the trick just fine, but would I be better off buying 3 * 47µF and a 15µF and paralleling them? At least ESL & ESR would drop, in theory...

[Starre]

I have read that parallell use of say 3 caps is even better than one big, so I think you can do that without problems.

[Adolf Corkscrew]

Hmm... Maybe I should try it out, then document the comparison here... I would also presume, that the parallel caps might even be better, but it wouldn't be the first time I was wrong a priori. Then again, putting hundreds of euros in caps just for the fun of it isn't something I currently can afford. To really do such a test, even only an open listening, all of the caps should of course be of the same variety and same voltage rating.

The Obbligato oil filled caps sold by Acoustic Dimension look very promising. Anyone tried these?

[JLOP]

Yes I did in Tannoy HPD 12" crossover. Was very impressed by the results : much better definition and treble sharpness, but not a tiring sound, very natural. Only negative point is that they are quite difficult to source.

[skorpion]

I have used the Obbligatos both in my 'Volks-OB':
My 'Volks-OB' Mission Accomplished and in the 'MJAO':
MJAO G 098 - The Anagram - Crossover revision
They perform exactly as JLOP says, very good, nothing to compare, I think, at the price.

Tony Gee has them in his capacitor test: Humble Homemade Hifi

I bought mine from DIY Hi-Fi Supply: Obbligato Film Oil Caps | Diy HiFi Supply

/Erling

[sharpi31]

On the basis that 80uF is approx half the value you need, and readily available as a motor run film cap, I would buy a number of cheap 80uF film caps from ebay and measure for pairs that totalled 156uF (or near enough).

There are always tons of Ducati, ASC, GE polypropylene (with & without oil) caps on ebay and they are not expensive.

I'd rather buy 8x ebay motor run caps and measure all to find two closely matched pairs, than risk spending big bucks on expensive audiophile caps that often have terrible tolerences compared to standard industrial stuff (ther are exceptions, but these are rare).

Here are some nice ones to cosider:

DUCATI 80uf CAPACITOR MOTOR RUN 450v 80mfd | eBay

ASC High Capacitance Polypropylene Film 80uf / 330vac AC Filter Caps | eBay

http://www.ebay.co.uk/itm/Mars-Mars2...item5193c09d20

[Adolf Corkscrew]

Originally Posted by skorpion

I have used the Obbligatos both in my 'Volks-OB':
My 'Volks-OB' Mission Accomplished and in the 'MJAO':
MJAO G 098 - The Anagram - Crossover revision
They perform exactly as JLOP says, very good, nothing to compare, I think, at the price.

Tony Gee has them in his capacitor test: Humble Homemade Hifi

I bought mine from DIY Hi-Fi Supply: Obbligato Film Oil Caps | Diy HiFi Supply

/Erling

I've used the dry type Obbligatos with good results in electronics, but in a crossover my experience is inconclusive, since the X/O was only partly with Obbligatos. They did make some improvement, but in a series crossover, all the caps should be the same. Any idea on how the oil type differs from the dry type? I've read T. Gee's page over and over again, but I like having second opinions, since these things are also matters of taste.

[Adolf Corkscrew]

Originally Posted by sharpi31

On the basis that 80uF is approx half the value you need, and readily available as a motor run film cap, I would buy a number of cheap 80uF film caps from ebay and measure for pairs that totalled 156uF (or near enough).

There are always tons of Ducati, ASC, GE polypropylene (with & without oil) caps on ebay and they are not expensive.

I'd rather buy 8x ebay motor run caps and measure all to find two closely matched pairs, than risk spending big bucks on expensive audiophile caps that often have terrible tolerences compared to standard industrial stuff (ther are exceptions, but these are rare).

Here are some nice ones to cosider:

DUCATI 80uf CAPACITOR MOTOR RUN 450v 80mfd | eBay

ASC High Capacitance Polypropylene Film 80uf / 330vac AC Filter Caps | eBay

Mars Mars2 Oval Run Capacitor 80 uf 370 V 12990 12090 | eBay

I appreciate your input, and for basic MKP's motor run caps seem to be quite adequate. But what I'm looking for now is something more "high end". In the aforementioned Tony Gee's cap test summary the Obbligato oil type receives a rating of 9, whereas the tried industrial types - oil or dry - fall between 6 and 7.6. Of course I know this is no official authority, but it's better than just saying "there's no difference between caps". And the price of those MKP in oil Obbligatos isn't exactly too high. They're about the same as those industrial types are.

I actually do think that at least some industrial types are very good caps in audio too. But not as good as the best specialised caps. The problem is to differentiate the overhyped and -priced crap from the real things. If I had infinite money (who would'nt wish for that...), I could just spend it away and just test everything. Maybe even learn something. Now I'm just trying to probe whether or not I should save some money buying a little cheaper or not. (Actually, the speaker is quite good as it is with the bundle of what-I-had-round -caps, but I'm just neurotic and want them all to be of the same type...)

[skorpion]

I have actually also used 1 pair of the Copper caps for treble HP. I don't think that you can hear a significant difference. Both perform very well in my opinion.

/Erling

[Adolf Corkscrew]

Originally Posted by skorpion

I have actually also used 1 pair of the Copper caps for treble HP. I don't think that you can hear a significant difference. Both perform very well in my opinion.

/Erling

Thank you! I think I'll take your advice on this, and try the oil types for the lower X/O-point. The price difference is quite much compared to not hearing the difference, so maybe my neurosis will be satisfied with the oil types. If they live up to expectations, they're actually quite cheap.