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Caps for crossover upgrade for Opera Grand Callas Loudspeakers

Hi, first of all excuse me for my English.
I’d like to upgrade crossover of my beloved Opera Grand Callas Loudspeakers
http://www.operaloudspeakers.com/en/collections/callas-line/grand-callas.html
I’ve got a Merging Hapi as dac, Soulution 721 preamplifier and Krell Fpb 400cx amplifier, I use pure Ag Lasound cables (http://www.lasound.it/en/)
Here you could find more information about my loudspeakers.
https://drive.google.com/open?id=0B9kNUs8PnpkEa21XMjRmaE5ZdWs
They use Scanspeak 9700 tweeter from 2khz and above, Seas 6" custom midrange from 200hz to 2Khz and two Scanspeak 8" aluminium woofers.
Woofer could be this, but I’m not sure
https://www.scan-speak.dk/products/prod-woofer/?single_prod_id=157
While midrange is very similar to this
http://www.seas.no/index.php?option=com_content&view=article&id=101:h1520-08-u16rcyp&cat...
Here is the schema of the crossover, maybe it could be quite different, I haven’t yet dismount the woofer in order to take photos, but this schema is taken from the my loudspeakers’ little sisters, the Opera Callas Diva, that are a little smaller and with only one woofer instead of two.
http://i66.tinypic.com/etil95.jpg
And here is a photo taken from Opera Callas Diva crossover.
http://i67.tinypic.com/16blocz.jpg
As you can see, and in this respect I know that it’s the same as my loudspeakers, capacitors used are Mundorf Evo Aluminium.
I’d like to change the 6,8 uF capacitor used for the front tweeter and the 10 uF used as bypass capacitors for midrange in order to obtain e more relaxing and refined sound. I’d like to have more air, more natural and organic sound without loss in high frequencies extension.
I like my loudspeakers very much, but sometimes I found the sound, especially with not perfectly recorded and mixed records, a little bit on the hard side in the uppermid frequencies, especially on female voices.
I think it could depends on Mundorf Evo caps that are known to be a little "nervous", so I think to go for a Jupite Copper Foil Paper and Wax caps for the 6,8uF (eventually with a Duelund Silver 0,01uF bypass) and maybe a Jantzen Alumen ZCap for 10uF midrange cap, I know it could be better to use another Jupiter Copper for midrange, but I don’t know if there is enough space for it.
Have you any suggestions?
For midrange caps what do you think of Jupiter VT? What are the differences between Jupiter VT and Copper Foil in terms of sound? And between Jupiter Vt and Jantzen Alumen Zcap?
Thanks.
grunter

Showing 7 responses by erik_squires

erik_squires
15,646 posts
 
Hi  @grunter

If a 10uF cap was exactly like 2 x 5uF caps and those were exactly 2 x 2.5uF caps you'd be correct.


However, in listening to Clarity CMR caps I have not found this to be true, but this could be due to the the specific crossover I was working on.


Audyn True copper caps are relatively inexpensive, so I strongly suggest listeners who are curious try it out for themselves, and come back and tell me I'm wrong. :D


Best,

Erik
erik_squires
15,646 posts
 
Ahhhh, that makes more sense, @dgarretson

Based on my experience, I'd really love to try using smaller CMR caps to build up larger values. I think there's something about the uF being larger than 4 ~ 5 uF that matters. I don't have any money for this and barely any energy either though. :)

Best,
E

erik_squires
15,646 posts
 
Hey @dgarretson

What uF were the Clarity you bypassed?
My experience has been that below 4-5uF I can't hear any difference in bypassing them.

I also used 0.047 Duelund pure silver caps on the 10 uF caps I have. No difference for me.

I needed at least 0.1uF to make a difference, and only on the bigger caps.

I forgot if you saw the speaker I put the CMRs in. :)


Best,

E

erik_squires
15,646 posts
 
So you have good experience with Clarity Cap CMR bypassed by a copper caps. Which one?


I used the Audyn TruCopper models.


In what do you prefer CMR Clarity Cap over Duelund and Jupiter?


Cost and size! But if I could afford Jupiter copper foils I would.  Unfortunately my current custom speakers require about 14uF in the tweeter, about $800 / speaker and that's just not money I have.


Mundorf Supreme <<<<< Clarity CMR (with bypass) < Jupiter


and never heard the Duelunds. I find the Clarity has a very neutral, and very open presentation. Jupiter adds sweetness. Mundorf to my ears adds a Disney-like sheen, or scintillation quality to everything and while it’s pretty, it’s unnatural and often too cool sounding for me.


erik_squires
15,646 posts
 
Actually, given the costs involved here, before you begin, you should probably invest in a Dayton DATS V2.

Measure the impedance of the entire speaker, and it will let you measure the ESR and DCR of any components you pull out.

Then you can use it along with something like XSim to simulate the electrical characteristics fully.

You'll also be able to use it to help you diagnose problems when you re-assemble the crossover.

Best,
E
erik_squires
15,646 posts
 
It would be interesting to see the impedance curve, but the 100uF shunt cap on the woofer is interesting. They usually need 0.5 Ohms to 2 Ohms to prevent an impedance issue in the next driver up.

Don't replace it willy-nilly. Measure the ESR and add a resistor if needed.


Best,
E
erik_squires
15,646 posts
 
Those caps are top notch for their type. Magico uses them or very similar, and .... I don't like them! :)

I far prefer Clarity CMR + 0.1uF Copper foil bypass caps. as giving a much more natural and relaxed presentation. If money is no object, size might be though, so be sure in any upgrades you check the physical dimensions, especially with the Jupiter and Duelund copper foil caps.
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