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Crossover cap upgrades for Heresy's


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I was so impressed with the sound improvement in my La Scala's after Dean reworked the networks and set the taps up to drop the squawker by 3 db that I see the merit of swapping out the old cheap caps. Apparently the caps leaked all over when I shipped the boards to him so it was time anyway.

These 84 Heresy's I just picked up would probably benefit from a cap upgrade as well. Here's my question, replacing the total of six caps with Theta Audiocaps can add up in cost pretty quickly and I wonder if using the Dayton or Solen metallized polypropylene for a lot less money will still be a large improvement over the old caps? I dont know much about this but I want to tackle it myself. Are the new caps polarized and if so can someone describe which way they orient on the crossovers? Thanks, Carl

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I thought the Dayton's were rebranded Bennics -- they look identical to me. However, the guys at PartsExpress say they aren't. O.K. I figure, they're not "rebranded", but probably rolled in the same factory.

The values in that network are small enough that you can go big quality without going broke. Don't cheat the circuit unless you absolutely have to.

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I suspect that difference you heard in your reworked crossovers was primarily due to the change in tap.

None of the capacitors in the E2 network in the 84 Heresy are polarized. Two are already metallized film, although mylar, not polypropylene, if IIRC. The other is a 33 uF nonpolarized electrolytic which I am sure was chosen by Klipsch on the basis of price. Large metal film capacitors are much more expensive, and much larger, than electrolytics. That said, I would be willing to bet that Klipsch also determined it would not make an audible difference.

I rebuilt the crossovers like yours with Solen capacitors, mainly to get rid of the electrolytic because electrolytics have a nasty property of failing over time. While I was in there, I replaced the other two capacitors with Solens also to match the changes I made on older Heresys that originally had the old motor caps.

I cannot say for sure that I can actually hear a difference in any of my Heresys after the crossover changes. I suspect any inprovements are likely to be swamped by the inherent distortion in the woofer, squawker driver, and tweeter, and differences between them between boxes.

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I posted this is another thread, but it applies here too:

Another option would be to replace all the caps with Dayton Poly caps then bypass each one of those with a 0.01uF AudioCap Theta cap. I read over on a Lansing forum where a guy had very good results doing that on his JBL horn's crossover. His results agree with a guy's high-end cap testing -- see http://home.zonnet.nl/geenius/Cap.html -- in that he recommends Thetas be used as a bypass caps. Although I have no practical experience (yet), I have to believe in the law of dimishing returns when it comes to upgrading caps.

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On 6/25/2005 9:56:07 AM STL wrote:

I posted this is another thread, but it applies here too:

Another option would be to replace all the caps with Dayton Poly caps then bypass each one of those with a 0.01uF AudioCap Theta cap. I read over on a Lansing forum where a guy had very good results doing that on his JBL horn's crossover. His results agree with a guy's high-end cap testing -- see
-- in that he recommends Thetas be used as a bypass caps. Although I have no practical experience (yet), I have to believe in the law of dimishing returns when it comes to upgrading caps.

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I would suggest that instead of the 0.01 uF bypass cap that won't pass audio that you use a teflon tie-wrap. Same effect on the sound and is cheaper.

Bob

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not to scare you from buying the dayton caps. The few i have tested have high ESR values and were either high or low in the 5% spec. i just dropped $100 for cornwall II parts from parts express. i purchased Solen caps, they were all very close to spec. They aren't much more than the dayton caps.

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On 7/3/2005 9:22:00 AM Jay L wrote:

not to scare you from buying the dayton caps. The few i have tested have high ESR values and were either high or low in the 5% spec. i just dropped $100 for cornwall II parts from parts express. i purchased Solen caps, they were all very close to spec. They aren't much more than the dayton caps.

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That is surprising, I have found just the opposite with my cap testing with the Daytons being better than Solen in ESR and more consistent cap to cap in capacitance.

Bob

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On 7/3/2005 9:46:38 AM BEC wrote:

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On 7/3/2005 9:22:00 AM Jay L wrote:

not to scare you from buying the dayton caps. The few i have tested have high ESR values and were either high or low in the 5% spec. i just dropped $100 for cornwall II parts from parts express. i purchased Solen caps, they were all very close to spec. They aren't much more than the dayton caps.

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That is surprising, I have found just the opposite with my cap testing with the Daytons being better than Solen in ESR and more consistent cap to cap in capacitance.

Bob

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bob,

i would guess you have tested many more than i have. i only had a hand full laying around which i based my decision on. if i were any of you guys on the fence and didn't have the opportunity to test different ones then i would go with bob on this one. i purchased a few extra of each cap so i got what i wanted, it worked out well for me. i now have a pair of cornwalls out in the shop just waiting for a place to set em up inside. 9.gif

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"Tweeter caps pass the signal directly through to the driver, and thus differences in cap quality are readily apparent."

An '84 Heresy uses the K77.

All Cornwall and Heresy speakers using the K77 have the signal feeding the tweeter having to also go throught the midrange cap. The MKII versions do not, they are direct from the input terminals, do not go through the midrange cap, nor the autoformer.

"I would suggest that instead of the 0.01 uF bypass cap that won't pass audio that you use a teflon tie-wrap"

"good one Bob!"

Bragging that you can't hear again?

I can hear small bypass caps, so can the engineers at JBL, they go to the expense of using them on many of their models.

An inexpensive speaker using the 2404 tweeter:

http://www.jblproservice.com/pdf/Network%20Schematics/4612OK%20Network.pdf

The $99 (1978) L-19/4408 bookshelf:

http://www.jblproservice.com/pdf/Network%20Schematics/4408%20Network.pdf

A mid-priced 12" two-way PA speaker:

http://www.jblproservice.com/pdf/Network%20Schematics/SR4722A%20Network.pdf

I don't like wine, but I am smart enough to know that I don't bring a bottle of Thunderbird as a gift for a dinner party.

You may not be able to tell the difference, but maybe a guest can.

To cheap to spend $1 extra?

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"I would suggest that instead of the 0.01 uF bypass cap that won't pass audio that you use a teflon tie-wrap"

"good one Bob!"

Bragging that you can't hear again?

I can hear small bypass caps, so can the engineers at JBL, they go to the expense of using them on many of their models.

Dennis,

I have a standing offer of a free bag of dog biscuits to anyone who can demonstrate the ability to hear the 0.01 uF cap we are talking about here.

Bob

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Guys,

I agree with Bob, there is no way you can hear the tiny increase in current

that will flow through a .01 uF cap when it's connected across another cap of

significantly higher value. The bottom line is people hear what they WANT TO

HEAR!

Everybody knocks Solen FastCaps. I have used literally hundreds of these and

of Hovland MusiCaps. I have had to return several hovlands because they were

out of their +=5% spec. I have NEVER found a FastCap out of speck. I have

had one short-circuited one that I had to be returned however.

I test every cap I use with a Stanford Research SR720 lcr meter that is in

current factory calibration (+-0.05%). It is connected to an old DOS computer through

an RS232 port which controls it and sorts a group of caps by value to make

matched sets. Here's an example of a group of eight 22 uFd FastCaps computer

sorted. The "Q" value is simply 1/D. The last column is the percent error

between each and the next one if it is to be used as a matched set of two.

The first column is a reference number I write one each cap with a grease

pencil.

4 C=21.84900 Q=3030.3 0.01 %

3 C=21.85200 Q=2500.0 0.02 %

5 C=21.85700 Q=1923.1 0.74 %

1 C=22.01800 Q=2173.9 0.07 %

7 C=22.03300 Q=2040.8 0.02 %

6 C=22.03800 Q=2222.2 0.10 %

8 C=22.05900 Q=2777.8 0.15 %

2 C=22.09200 Q=2381.0

Al K.

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Al,

About a year ago, I bought up and tested a couple of batches of Solens and Daytons. It that test of those batches, the Daytons looked a bit better than the Solens. Might get a different idea if I did the same test again with two different batches. All were good caps, however, and fine for crossover use.

Bob

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Bob,

The Solen caps are very consistant from batch to batch. The batch of 22 uF I tested above is typical. I have never tested any of the other brands of caps to do a real comparison. I have beed quite happy with the Solens. I think they are probably not quite as good as caps with thicker metalization, but they are in the same "league".

BTW: I am staring to double them up rather than put a 1 uF bypass around a larger value. Not only is the "Q" (ESR) better but they allow me to match sets even closer. In a typical sorted list, I pair up the 1st with the 4th cap on the list and the 2nd with the 3rd cap. The combination makes extremely close pairs!

Al K.

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