Dave A Posted March 2, 2019 Share Posted March 2, 2019 Today I was working on a set of HIE crossovers for an old set of HSM's. Besides the oil slobbering on one of them all of these were bad. That ESR reading was typical of every one. I look at these just to see how bad they are after they have been cut out and replaced just for curiosity. You hang on to those old Mylars or Cans you are not doing yourself any favors. 1 Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted March 3, 2019 Share Posted March 3, 2019 Just turn them around and you can start them over. Quote Link to comment Share on other sites More sharing options...
Dave A Posted March 3, 2019 Author Share Posted March 3, 2019 1 minute ago, CECAA850 said: Just turn them around and you can start them over. I heard if you turned them upside down for a while the ESR would run out and you could reuse them. Quote Link to comment Share on other sites More sharing options...
babadono Posted March 3, 2019 Share Posted March 3, 2019 What frequency is your meter using to measure ESR? Usually it's 60 or 120 HZ. If that's a tweeter circuit cap the ESR MIGHT NOT be that high at High freqs. I'm not telling anyone not to use better caps though. Quote Link to comment Share on other sites More sharing options...
tigerwoodKhorns Posted March 3, 2019 Share Posted March 3, 2019 If they are from the 1970s or older and have oil coming out you may have PCBs. Nasty stuff and environmental waste. 1 Quote Link to comment Share on other sites More sharing options...
Schu Posted March 3, 2019 Share Posted March 3, 2019 Will they explode if you toss'em in a fire? Fwiw, how did they actually sound prior to removal? Quote Link to comment Share on other sites More sharing options...
seti Posted March 3, 2019 Share Posted March 3, 2019 I have never used an ESR meter can you test at specific freq? Quote Link to comment Share on other sites More sharing options...
Dave A Posted March 3, 2019 Author Share Posted March 3, 2019 1 hour ago, babadono said: What frequency is your meter using to measure ESR? Usually it's 60 or 120 HZ. If that's a tweeter circuit cap the ESR MIGHT NOT be that high at High freqs. I'm not telling anyone not to use better caps though. OK the B&K manual said in general 1k is where to measure. The range on the meter is 100,120,1K,10K Grabbing at random one of the 2uf cans. 100=6.22 ESR 120=5.28 1K=.848 10K=.194 Next I have a 2uf Dayton 1% cap 100=.075 120=.054 1K=.020 10K=.005 Next Sonicap 8uf 100=.021 120=.019 1K=.006 10K=.003 The Sonicaps Bob likes so well consistently measure better than the Dayton. Many people use the Daytons and seem happy and I am one of them in general. I had other brands and values wjich I am not going to bother with tonight. I thought you posed an interesting idea so I went and measured. 2 Quote Link to comment Share on other sites More sharing options...
Dave A Posted March 3, 2019 Author Share Posted March 3, 2019 39 minutes ago, Schu said: Will they explode if you toss'em in a fire? Fwiw, how did they actually sound prior to removal? The ends will pop off. Things were in general muddier. Quote Link to comment Share on other sites More sharing options...
garyrc Posted March 3, 2019 Share Posted March 3, 2019 @Dave A, How old were the bad ones? Quote Link to comment Share on other sites More sharing options...
glens Posted March 3, 2019 Share Posted March 3, 2019 5 hours ago, Dave A said: Next I have a 2uf Dayton 1% cap 100=.075 120=.054 1K=.020 10K=.005 Next Sonicap 8uf 100=.021 120=.019 1K=.006 10K=.003 That's what I'm talkin' about - above & beyond the call of duty! The 8 uF cap exhibits 1/4 the reactance at each frequency as the 2 uF cap and the ESR at just a glance appears to follow a similar pattern. Interesting. Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted March 3, 2019 Share Posted March 3, 2019 If you want to go back with similar look at Genteq. I've built 2 sets with them and they sound great. I even sent a set to Bob and he said that they measure really well also. They keep the look of the original crossover for those that care about such things too. Quote Link to comment Share on other sites More sharing options...
karlson3 Posted March 3, 2019 Share Posted March 3, 2019 hey Dave A - since you've got a good meter, there's an experiment I'd like to see you do sometime - - solder one of those highly touted (but cheap) Dayton film and foil caps in the range of 0.047uF to 0.1uF across a Dayton ~2uF cap then compare that composite cap to a Sonicap with the same approximate value to see if that bypass cap (which would have insignificant effect upon reactance compared to 2uF) actually has any measurable effect upon ESR. When measuring 2uF caps, I was surprised to see some old Klipsch Aerovox still pretty good. The dirt cheap red "Audiophiler" cap had very tight tolerance and the lowest ESR of any 2uF cap in my pile. (maybe its too good electrically as can sound "harsh" - lol). Metallized paper MBGO caps measured with lower ESR than some foil/paper KBG. (the MBGO are physically considerably smaller than KBG for a given capacitance and voltage rating) Lossy caps might be good in a "harsh" system. From a purely electrical standpoint (and not taking in DA), can one somewhat emulate a lossy cap's "tone" by putting say a half-ohm resistor in series with that cap? A switch could be put across the cap for quick A-B. Here's something - - Stan Ricker once told me how he used Altec Duplex. Instead of the conventional crossover, he pretty much only had a small value highpass cap (IIRC in the ballpark of 2uF) to the compression driver and no pad attenuation, so the very top would be brighter than stock configuration. More interesting - he used a number of motor run oil damped caps in series to get that value and had a theory of "large plate area" sounding better - so doubt if he was freaking out over cap ESR. Somewhere deep in my mess is a cheap ESR meter - it seemed to read C, R, and L reasonably well and ESR consistently - but its stupid cheap leads and jacks are horrible (no soldering to the clip things - crappy thin wire - musta cost a billi-penny to make 1000 units) If I can find it, I'll try to solder some permanent leads to its jacks inside. hey CECAA850 - those are nice looking caps - great to hear they sound good too. Quote Link to comment Share on other sites More sharing options...
Dave A Posted March 3, 2019 Author Share Posted March 3, 2019 7 hours ago, garyrc said: @Dave A, How old were the bad ones? My guess would be early 80's. The pro serial numbers are harder to date and I have not found what year they were made yet. 1 hour ago, CECAA850 said: If you want to go back with similar look at Genteq. I've built 2 sets with them and they sound great. I even sent a set to Bob and he said that they measure really well also. They keep the look of the original crossover for those that care about such things too. OK what would be the reason for using these besides appearance? Quote Link to comment Share on other sites More sharing options...
Deang Posted March 3, 2019 Share Posted March 3, 2019 Physical protection and damping. Quote Link to comment Share on other sites More sharing options...
Dave A Posted March 3, 2019 Author Share Posted March 3, 2019 18 minutes ago, karlson3 said: Lossy caps might be good in a "harsh" system. From a purely electrical standpoint (and not taking in DA), can one somewhat emulate a lossy cap's "tone" by putting say a half-ohm resistor in series with that cap? A switch could be put across the cap for quick A-B Wouldn't that be a hoot if you could duplicate those $500 super duper beeswax impregnated whizbangs "tone" with a cheap cap and a pot. 22 minutes ago, karlson3 said: hey Dave A - since you've got a good meter, there's an experiment I'd like to see you do sometime - - solder one of those highly touted (but cheap) Dayton film and foil caps in the range of 0.047uF to 0.1uF across a Dayton ~2uF cap then compare that composite cap to a Sonicap with the same approximate value to see if that bypass cap (which would have insignificant effect upon reactance compared to 2uF) actually has any measurable effect upon ESR. I have read about that but forgot it after I got my good meter. I will try this some day. Having a good meter has also paid off with inductors where I can unwind one to get a different value and know I am accurate. Quote Link to comment Share on other sites More sharing options...
Dave A Posted March 3, 2019 Author Share Posted March 3, 2019 2 minutes ago, Deang said: Physical protection and damping. I have wondered about the protection aspect. I have no idea how tight is too tight with cable ties and those nylon blocks most often used to mount capacitors. How tight before you can impact the side of the cap is a thought I have at times and even though it takes time I am wondering about siliconing them on instead. Something else I am starting to do is use those cable ties that have a screw hole in them and not use the nylon blocks at all since I figure they would be the big offenders in damage. Explain damping and why you choose not to do it. I have not heard that term before re capacitors. Quote Link to comment Share on other sites More sharing options...
CECAA850 Posted March 3, 2019 Share Posted March 3, 2019 I'll defer to Dean on the technical aspect. In real world application, I really like how they sound. My simple thinking was that going with that style cap would be close to how the originals sounded when new. Quote Link to comment Share on other sites More sharing options...
karlson3 Posted March 3, 2019 Share Posted March 3, 2019 at some point I think Klipsch was using block caps in the Heritage crossovers. I have a bunch of 12uF of that type and they seemed to sound decent with K55V/511B, APT150 and FH1 Quote Link to comment Share on other sites More sharing options...
Deang Posted March 3, 2019 Share Posted March 3, 2019 I usually put a piece of Deflex or foam under the capacitor before I cinch the tie, and tighten it just enough to hold the capacitor down. Yeah, cranking down on the tie is a bad idea, and will definitely crease and damage the film. When using the screw hole type, position the tie around the epoxy end caps. Damping: internal protection from mechanical/acoustic vibration (and heat). I primarily use Jupiter and Arizona, which are well built, fully protected capacitors. Arizona’s are oil filled, and the Jupiter’s use wax. There are other considerations, but I’m sure most are as tired hearing about them as I am writing about them! Quote Link to comment Share on other sites More sharing options...
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