clermontcop Posted February 20, 2010 Share Posted February 20, 2010 I have a pair of Heresy crossovers, however im not familiar with the caps on this particular crossover. Could someone tell me what the difference is between this crossover and the heresy crossover with the oil can caps? Quote Link to comment Share on other sites More sharing options...
djk Posted February 20, 2010 Share Posted February 20, 2010 It has mylar caps for the horns, and a 12dB section on the woofer with an electrolytic. Quote Link to comment Share on other sites More sharing options...
clermontcop Posted February 20, 2010 Author Share Posted February 20, 2010 Would you recommend replacing these caps? How likely are these to go bad compared to the oil cans? Quote Link to comment Share on other sites More sharing options...
Groomlakearea51 Posted February 20, 2010 Share Posted February 20, 2010 They probably should be replace with a new set. I recommend Sonicaps for general late model Heresy-I's (Type E2's). Matt, can you give me a call about those cabinets you have for me? Quote Link to comment Share on other sites More sharing options...
Malcolm Posted February 21, 2010 Share Posted February 21, 2010 Not sure if the 2 mFs are mylar, but they are metallized film of some sort. They aren't likely to go bad. And IMHO they are likely better than the paper in oil caps that were used in earlier Heresys. You can replace them with you favorite "audiophile" caps if you want, or just a decent metalized polypropylene. The other is an electrolytic capacitor, which is guaranteed to go bad sooner or later. It was used because an electrolytic is cheap, gives relatively large capacitcance in a given space compare to other types of capacitors, and the technical requirements for what it is doing aren't very demanding. You can wait until it starts to go bad and replace it with another very cheaply, or you can replace it now or later with a better quality part like a metallized polpropylene capacitor which will be much larger and more expensive. Technically it will be much better, but I doubt the difference will be audible unless the electrolytic is going bad. Quote Link to comment Share on other sites More sharing options...
djk Posted February 21, 2010 Share Posted February 21, 2010 " They aren't likely to go bad. " Really? Lead attachments can and do fail over time, especially under high current use (as in crossovers). In fact, most capacitors fail because the ESR goes up, not the value changing. "And IMHO they are likely better than the paper in oil caps that were used in earlier Heresys." Klipsch tried using polyester film caps in the 70s, and went to more expensive custom made oil caps. I wonder why? Quote Link to comment Share on other sites More sharing options...
Malcolm Posted February 21, 2010 Share Posted February 21, 2010 Lead attachments can and do fail over time... Picky, picky...True of all caps. Some fail, some don't. But then nothing is truly permanent. Klipsch tried using polyester film caps in the 70s, and went to more expensive custom made oil caps. I wonder why? Because "audiophiles" wanted them? Are the expensive cutom made oil caps used in any line except the Heritage line? I'll stand by my statement about the paper and oil caps used in the Heresys. PWK does not seem to have been concerned about anything except a rough approximation of the required capacitance (20% tolerance) from what I have seen in the Heresys I have owned and seen. He used whatever was available. I have several pairs of Heresys, and have owned others, and every pair has is different (different manufacturers, different working voltages, etc.) When he did make a change, it was to the film caps like in the OPs Heresys. So, they must have been considered an improvement, no? Now, could the custom oil caps used in the Heritage line today be an improvement over the the old paper in oil caps that were used in the Heresys, possibly. BTW are the expensive custom made oil caps paper in oil or film in oil? I was wondering about that. And why do folks like ALK and BEC not use oil caps? Quote Link to comment Share on other sites More sharing options...
djk Posted February 22, 2010 Share Posted February 22, 2010 "But then nothing is truly permanent." Film-and-foil caps with soldered connections last longer than swedged connections. "Because "audiophiles" wanted them? " No such animal in the early 70s. "And why do folks like ALK and BEC not use oil caps?" Have to ask them. Quote Link to comment Share on other sites More sharing options...
BEC Posted February 22, 2010 Share Posted February 22, 2010 Just happened to run across this example of a bad cap working on a CF-3 crossover today. The reason this crossover is being worked on is that there was no output from the HF. These speakers were made from 1994 to 1996, so this cap is 14 to 16 years old. It is supposed to be a 4.25uF cap, probably mylar. You can see that capacitance is off a bit, about 6 percent, but look at the ESR. 405 ohms!! Nothing was going to get through this cap. Bob Crites Quote Link to comment Share on other sites More sharing options...
JL Sargent Posted February 23, 2010 Share Posted February 23, 2010 Hmmm. So the capacitance was likely still within tolerance yet literally no current flow. That's really interesting. Quote Link to comment Share on other sites More sharing options...
djk Posted February 24, 2010 Share Posted February 24, 2010 Most old caps fail in circuit due to ESR, not value change. That's the reason BEC owns a good LCR bridge, cheap ones only measure the value. I gave away my cheap bridge. Quote Link to comment Share on other sites More sharing options...
seti Posted February 24, 2010 Share Posted February 24, 2010 Wow very interesting. Quote Link to comment Share on other sites More sharing options...
Deang Posted February 25, 2010 Share Posted February 25, 2010 What would the meter read if a cap was shorted? Quote Link to comment Share on other sites More sharing options...
BEC Posted February 25, 2010 Share Posted February 25, 2010 Dean, That is an excellent question. Let's do a test. Bob Crites Before: A mildly bad on ESR 3uF mylar cap. Quote Link to comment Share on other sites More sharing options...
BEC Posted February 25, 2010 Share Posted February 25, 2010 Same cap now shorted. Bob Crites Quote Link to comment Share on other sites More sharing options...
Groomlakearea51 Posted February 25, 2010 Share Posted February 25, 2010 Looks like my method of shorting something out.... [H] Quote Link to comment Share on other sites More sharing options...
JL Sargent Posted February 25, 2010 Share Posted February 25, 2010 Can you measure the ESR of caps in circuit? I have a vibration analyzer that has quit working. I suspect the power board is bad which has lots of small caps on it. The equipment is no longer manufacturered or supported so I'm looking for cap testing possibilities. Quote Link to comment Share on other sites More sharing options...
BEC Posted February 25, 2010 Share Posted February 25, 2010 Can you measure the ESR of caps in circuit? I have a vibration analyzer that has quit working. I suspect the power board is bad which has lots of small caps on it. The equipment is no longer manufacturered or supported so I'm looking for cap testing possibilities. I think so. Probably at reduced accuracy but likely would pick out caps bad enough to cause circuit failure. Also, I think the caps need to be above 1uF for the ESR meter to work properly. Bob Crites Quote Link to comment Share on other sites More sharing options...
JL Sargent Posted February 25, 2010 Share Posted February 25, 2010 That's good stuff Bob. Thanks. Now to hunt me up one of those meters or similar. Apparently the BK 886 adds the in-circuit testing capablility with a 100Khz test frequency? I'm sure that feature cost more dollars. That's a nice meter you have there Bob. Quote Link to comment Share on other sites More sharing options...
Deang Posted February 25, 2010 Share Posted February 25, 2010 LOL, now I know what to do if I need a 20uF cap real quick. Quote Link to comment Share on other sites More sharing options...
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