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Chorus II crossover conundrum! leok, deang, alk, mike stehr; share your wisdom!!!!!


krustyoldsarge

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Dean,

Yes.. It's not the hobby, it the nature of the human brain! I might do a listening test, but I will let my wife listen. I'll trick her into thinking there is definitly a difference and I'll ask her to describe the difference. Even this is dangeroius becasue he may manufacture a difference by forcing herself to pick something that isn't there!

Al K.

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As far as I can tell, from the tests performed by Al, one of which I suggested and the other designed by Al, the Hovland caps Al used did not need conditioning. Before this point, Al was certain Hovland caps don't need conditioning. There was nothing in my reference concerning cap construction, my experiences, that he found significant. And the tests, even in my judgement, did not support my claim. He has made it clear he is still certain Hovland caps don't need conditioning.

Having had several experiences with the need for and impact of conditioning, in tantalum and and a high power paper-oil-polypropylene caps (non-audio applications) and substantial success using it on crossover caps, I will continue to recommend it. Unlike Al, I don't have the equipment to check the performance of a crossover electronically after it's completed. If a cap, or set of caps, is (are) not performing correctly, I won't know it and will asume the caps are a bad idea or there's a design problem. For me, conditioning is a good way to know the caps aren't defective, and a good way for me to be sure that the small manufacturing defects that I believe may exist, have been cleared. For people who believe cap manufacturers ship a perfect product every time, I can appreciate that conditioning will appear to be a waste of time and resources. Since Al tests his crossovers, he will catch a poor performer.

I have a few caps that I removed from my RF-7s. They've never been conditioned and have reason to believe they are not performing as well as they would after conditioning. I will spend a little time trying to figure out a way to expose what I think is degrading the performance.

Leo

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Leo,

I agree! I think you simpy have to readjust your thinking from "conditioning" to "quality control testing" with respect to the procedure of charging a cap in both directions before use. I test all my caps for capacity value to make matched sets. This will almost always catch a bad one. I have cought two Hovlands there were out of the 5% value speck but never found one with leakage or loss. I have also found one bad Solen Fastcap. It was nearly shorted. Each network I built is tested for insertion loss through each each channel. That has caught at least one off value inductor that I can remember and one mis-makded 10 Ohm resistor!

BTW: I did a listening test using the two caps in the oscilloscope test. I put a square wave through both of them alternately into a headphone. The two sound identical to my ear.

Al K.

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Well my Chorus II's are long gone, but I still kept the parts. Except for the 3.6 millihenrie solid core air chokes, ebay got them.....

I basically just hard-wired everything on piece of MDF painted black. It looked quite similiar to what Al builds.

I just replaced things with better parts I suppose.

In the woofer circuit, I replaced the 3.5 mh inductors with Solen 12 awg solid-core at 3.6 mh. They didn't have 3.5 millihenrie. The 68 mic 'lytic was replaced with a big ol' Solen 68 uf metalized polypropelene.

The midhorn circuit used a big Northcreek Crescendo 6 uf cap,(couldn't afford Hovland in that value) with a Mills 12 watt 20 ohm resistor, the stock autoformer, and a 1.8 millihenrie Solen air core inductor, 14 awg? litz wire.

The tweeter circuit used two Solen 2 uf with a Solen .16 mh litz wire inductor, can't recall the awg.

The Solen 2 mic caps were bypassed with the Northcreek Harmony 0.22 uf bypass caps.

If were to keep the Chorus II's, I would have tried better caps in the tweeter circuit and tried to get away from the big 68 uf Solen in the woofer circuit.

I dunno......

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You're a trip Al, too funny.

True confession time, and I really don't feel to comfortable saying this -- but when I was rebuilding DQ-10s and Advents a while back, I definitely preferred electrolytics in the LF section of those speakers. The bass was definitely punchier. The only reason I use polypropylenes for the RF speakers is because they are closest to what Klipsch uses there.

The Crescendo metallized polypropylenes are good caps, if they had more values I would use them.

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Thanks Mike!

Are you interested in selling the parts you built your ChorusII crossovers with? PM me if so.

I'm not too keen on using that a big Solen in the LF circuit either, even though a similar approach worked out okay for my KG4's. I scrounged some 6uf Aerovox PIO's (anyway) and might use these in parallel with some film caps to get the 68uf value. Probably going to end up putting the woofer stuff on a separate board if I go that route.

Was half expecting to see the dialogue between Al and Leo erupt. Part of what makes the forum fun!

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Sarge,

Nah.. I don't get mad when somebody challanges me on something. The only time I do is when I am called and idiot or the like. Leo had an experience that was probably just a bad cap and jumped to the conclusion that the caps had to be "conditioned". It's something that is easy to do. I have done it enough myself! The debate was settled scientifically, with no screaming!

Dean,

Electrolytics are Ok in the woofer filter. I realy don't like using them uness they are the non-polarized type. It's usually just a way to cut cost though. They certainly are no better.

Al k.

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