Deang Posted December 8, 2005 Share Posted December 8, 2005 How about at the next get together I'll bring my Type AA (or Type and you all bring your Type AA (or Type -- and we'll let everyone in the room decide. Quote Link to comment Share on other sites More sharing options...
BEC Posted December 8, 2005 Share Posted December 8, 2005 We were supposed to do that at Hope but you came up with some lame excuse at the last moment and didn't show. Bob Quote Link to comment Share on other sites More sharing options...
NOSValves Posted December 8, 2005 Share Posted December 8, 2005 We were supposed to do that at Hope but you came up with some lame excuse at the last moment and didn't show. Bob Boy were getting testy aren't we? Its just a tad but more of a hassle for Dean to get to Hope with all the kids and what not now isn't it. I know first hand what the room would most likely decide. Quote Link to comment Share on other sites More sharing options...
BEC Posted December 8, 2005 Share Posted December 8, 2005 Craig, Just joking with Dean and he knows it. Bob Quote Link to comment Share on other sites More sharing options...
Deang Posted December 8, 2005 Share Posted December 8, 2005 lol -- he gotcha Craig. Quote Link to comment Share on other sites More sharing options...
NOSValves Posted December 8, 2005 Share Posted December 8, 2005 Yea I guess he did! I thought he was picking on poor Dean. Quote Link to comment Share on other sites More sharing options...
colterphoto1 Posted December 9, 2005 Share Posted December 9, 2005 Save me the reading guys. If I want to swap out the caps in my many AL/B/E, which brand/type cap should I buy. Simple question, simple answer. Side note. I own too many cabinets to afford having anyone perform this service for me. I have to wield the solder gun myself. So don't even pretend to sell me a new design, your services, etc. No offense, but I'm looking at like 20 crossovers total. Thanks Michael Quote Link to comment Share on other sites More sharing options...
DizRotus Posted December 9, 2005 Share Posted December 9, 2005 Michael, What did PWK use or what does BEC use? One of the answers to those questions could be your answer. If you were doing a single pair, then the additional cost for something boutique, that some people feel sound better, would not be a big deal. PWK selected, and BEC selects, caps based on performance, quality and value. Quote Link to comment Share on other sites More sharing options...
NOSValves Posted December 9, 2005 Share Posted December 9, 2005 Michael, What did PWK use and what does BEC use? The answer to those questions could be your answer. If you were doing a single pair, then the additional cost for something boutique, that some people feel sound better, would not be a big deal. PWK and BEC selected the caps based on performance, quality and value. There is the big misconception!! PWK did not use these GE caps ever!! The GE cap are not paper in oil. The motor runs PWK used were surplus military paper and oil. I would be willing to bet you a dime to a dollar those caps never testing or sounded anything like the caps BEC uses. Of course that fact will never be proven one way or the other since fresh examples of the original are not being made. Just because they were both motor run types doesn't mean diddley squat. Craig Quote Link to comment Share on other sites More sharing options...
sfogg Posted December 9, 2005 Share Posted December 9, 2005 " The motor runs PWK used were surplus military paper and oil. I would be willing to bet you a dime to a dollar those caps never testing or sounded anything like the caps BEC uses. Of course that fact will never be proven one way or the other since fresh examples of the original are not being made. " Were the caps even 'fresh' when PWK used them? If they were surplus they may have been sitting in a warehouse for 20 years before he bought/used them. Shawn Quote Link to comment Share on other sites More sharing options...
NOSValves Posted December 9, 2005 Share Posted December 9, 2005 Another good point. I bet in every test you could through at the two caps in question the GE's out scored the original then and now. I think that is exactly why I find them bright and pesky in the top end when you push up the SPL with a stock configured original type network. I'm pretty darn sure PWK auditioned things and didn't simply use what tested best. Craig Quote Link to comment Share on other sites More sharing options...
BEC Posted December 9, 2005 Share Posted December 9, 2005 I havent found many caps that PWK used that I would consider to be motor run caps. Most are rated 100 VDC or 100 VAC. Also, I think that someone on here said that Klipsch ran out of the surplus military caps around 1970. Also, I don't know what material the original caps were made of, but, I don't think they are paper after the early 70s anyway because many of the old original caps still test better than a new PIO cap. Bob Quote Link to comment Share on other sites More sharing options...
Jeff Matthews Posted December 9, 2005 Share Posted December 9, 2005 Okay, threads still going. Not that I care, but why doesn't somebody who has the equipment/materials (I don't) try this: Get two identical amps, two identical CD players and two identical pairs of speakers. Think anyone can agree on what these might be? Set the speakers up in the same positions and use Crites' switch box. Do your A/B test with 5 people. Play at the same volume (I wonder if anyone could agree what volume would be a good test). Tell the subjects you are testing Set 1 and Set 2 to see which is better. Do not tell them which is Set 1 and Set 2 when the test is being conducted. Play something like this: Set 1 and Set 2 - and ask all 5 separately which is better and why. Set 1 and Set 2 - same question Set 2 and Set 2 - same question Set 1 and Set 2 - same question Set 2 and Set 1 - same question Set 2 and Set 2 - same question That should be enough. If you get answers all over the place, there is no significant difference. If you want to blame it on their ears, you shouldn''t forget the ears are what it's all about. I would say the time it takes for someone who has the equipment to do this would be far less than the time it has taken for this thread to develop to this point and still go nowhere. Quote Link to comment Share on other sites More sharing options...
NOSValves Posted December 9, 2005 Share Posted December 9, 2005 I havent found many caps that PWK used that I would consider to be motor run caps. Most are rated 100 VDC or 100 VAC. Also, I think that someone on here said that Klipsch ran out of the surplus military caps around 1970. Also, I don't know what material the original caps were made of, but, I don't think they are paper after the early 70s anyway because many of the old original caps still test better than a new PIO cap. Bob I'm sure you have plenty of them lying around cut some apart and look at what is inside no need to guess. I bet there PIO types. I can gaurantee one thing there not metalized poly anything.. Craig Quote Link to comment Share on other sites More sharing options...
BEC Posted December 9, 2005 Share Posted December 9, 2005 Good idea Craig. Been meaning to do that so, no time like the present. Here is a Aerovox 4 uF cap from a 70s Klipsch Type B. It is a film and foil. Don't know what kind of film. Bob Crites Quote Link to comment Share on other sites More sharing options...
Deang Posted December 9, 2005 Share Posted December 9, 2005 I suspect the older cans were paper in oil, they had to be because polyester dielectric didn't exist at the time. At some point they probably changed over to cans using a polyester dielectric (like the cut open can in the previous post). The low voltage ratings indicate they were used for ceiling fans and the like. Ceiling fans were everywhere before the advent of air conditioning. A stock can from the inside of a later model Cornwall or Heresy using a polyester dielectric that's still in good shape probably does test better in ESR than a new PIO, but we are still in the mOhm area here. Random samples 02.20 µFd. 400/450 VDCBrand Equivalent Series Resistance Dissapation Factor1. JENSEN 44.20 mOhms .6000 @ 1kHz. & 120Hz.2. JENSEN 37.70 mOhms .6200 @ 1kHz. & 120Hz. 1. auricap 15.90 mOhms .0000 @ 1kHz. & 120Hz.2. auricap 12.20 mOhms .0000 @ 1kHz. & 120Hz. Quote Link to comment Share on other sites More sharing options...
BEC Posted December 9, 2005 Share Posted December 9, 2005 The new Jensen PIOs I measured were closer to 1/2 ohm ESR. The Aerovox I took apart for the above picture measured about 0.4 ohms ESR. Bob Crites Quote Link to comment Share on other sites More sharing options...
BEC Posted December 9, 2005 Share Posted December 9, 2005 Dean, Polypropylene was developed in 1951. I know that it was used as capacitor dielectric at least by 1974. Does anyone know of its earliest use as a dielectric? Bob Quote Link to comment Share on other sites More sharing options...
BiggerIsBetter Posted December 9, 2005 Share Posted December 9, 2005 I have '81 Corns with the Aerovox similar to what Bob pictured. I have not completed building my ESR meter yet but I would: 1) Not assume they are all worn out. Similar caps form that company have around 9000 hour life at rated voltage, which should be 10 times that in a speaker application. I'm sure many are leaking, but I bet mine test close enough to new to be representative of what that cap did sound like back in the day. 2) Not assume that any new "modern" cap will automatically sound "better." I did and switched to Dayton metalized. At first I did not like the change, sure some more detail, but at the expense of thin and bright. After listening (or breaking in of you buy that) and some crossover changes I have convinced myself that they are slightly better overall. But I would hate to do a back to back, blind, test as I just might pick those "crappy old" aerovox caps. I have some Jantzen's on order to make the changes necessary for the cornscalas in the works and do plan to try some Mundorf's once I have the exact values worked out. Seems every has the Thetas and I at least want to be a bit original.... If I had to do it all again, the first mod I would make would be the nail the back covers on. Why, to reduce cabinet resonance? No, the keep me from screwing around with a good thing. Quote Link to comment Share on other sites More sharing options...
colterphoto1 Posted December 9, 2005 Share Posted December 9, 2005 Okay, threads still going. Not that I care, but why doesn't somebody who has the equipment/materials (I don't) try this: Get two identical amps, two identical CD players and two identical pairs of speakers. Think anyone can agree on what these might be? Set the speakers up in the same positions and use Crites' switch box. Do your A/B test with 5 people. Play at the same volume (I wonder if anyone could agree what volume would be a good test). Tell the subjects you are testing Set 1 and Set 2 to see which is better. Do not tell them which is Set 1 and Set 2 when the test is being conducted. Play something like this: Set 1 and Set 2 - and ask all 5 separately which is better and why. Set 1 and Set 2 - same question Set 2 and Set 2 - same question Set 1 and Set 2 - same question Set 2 and Set 1 - same question Set 2 and Set 2 - same question That should be enough. If you get answers all over the place, there is no significant difference. If you want to blame it on their ears, you shouldn''t forget the ears are what it's all about. I would say the time it takes for someone who has the equipment to do this would be far less than the time it has taken for this thread to develop to this point and still go nowhere. Jeff, it's Econ 270- Statistics for Business. Basic rule, for any testing to be statistically valid, N (number of samples) must be equal to or greater than 30, otherwise the math falls apart. There's lots more to stats and probablility than a simple double blind test. When you say significant difference, you are talking about a very distinct mathematical model. I do think we're getting somewhere recently, discussing the working innards of different materials vs the methodolgy of xover practice. They are both important, but the basic question remains "what is the best TYPE of cap to use when just replacing the caps?' Michael Quote Link to comment Share on other sites More sharing options...
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