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Madisound Surplus Polyproplyne Capacitors


ka7niq
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For My Electro Voice Sentry III Crossover Rebuild, I need the following caps 3 - 30uf 1 - 17.7uf and 1 - 2uf - times 2 of course for the pair of speakers.

Two of the 3 - 30uf caps roll off the woofer, and one keeps lows out of the horn midrange, the stock caps were all the same brand, and 36 years old.

The 17.2uf cap rolls off the midrange horn , and the 2uf cap is on the tweeters (ST 350)

Madisound has these 10UF Poly Caps on sale for 60 cents each. They are sold as surplus caps. The company TYEE is out of Fullerton California, and has been in business since 1998, so at the very most, the caps are 12 years old, maybe less ? They are NOS I plan to take 3 of these 10 UF and combine them to make up one 30uf cap. This will give me the 30uf I need, and even lower ESR then one 30uf cap (resistance in paralell) For the 17.7 and the 2uf Caps, I ordered Solens, and a surplus 2uf Mylar from Madisound, just to have something else to roll. Unfortunately, all the Motor Run Caps I ordered will not fit! So I was going to give this a try. Anyone ever used these Madisound Surplus Poly Caps before ? And what do you think of using a bunch of caps to make the desired capacitance vs one cap ? I plan to soak them in Coconut Milk overnight, for a sweeter sound ! Seriously, 30UF Poly Caps are not cheap, and I need a total of 6 of them for my pair of speakers, At 20 bucks a shot, thats 120.00 ! Comments ?

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You mention the ESR. Well I just wonder what the ESR of the NOS caps will be. IF they are 10 to 12yrs old the ESR might be higher than desired and might be much higher than a single 30uf Solens or such. Just something to consider. Parts Express has the Solens 20uf 400v caps for 8.99 each.

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Yes, I need 30uf, not 20. The E/V Sentrys use the same brand of caps for both sections of the woofer to mid crossover, so I kind of wanted to keep that the same. Bob Crites told me that in a woofer dump cap, I could use electrolytic, since all they do is roll the woofer off. But a 60 cents a cap, I thought I would go all poly. I have no idea what the ESR of these surplus poly caps may be, but it can't be as high as the 36 year old Mylars that came stock in here, and are still working fine.

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Deep thoughts.........

I'm not sure I'd argue with Bob Crites. He's done as many crossovers as anyone I know of. Pretty darned good at them too as many here can testify to.

Age is a killer of caps.

We shall see, maybe Madisound has some equipment to check ESR ? I can not imagine them selling a bad capacitor, they have way too much to loose. Their market is hobbyists, and speaker modifiers. If word got out they were selling bad capacitors, that could be like a restaurant known for food posioning !!! I am actually thinking just the opposite. The company who made these surplus caps has only been making caps since 1998, thats only 12 years, if these are that old ? Heck, how do you know when you buy a Solen or an Auricap or a Mundorf it is "brand new' ? That sucker may have sat for 10 years ?

Bob Crites sells Sonicaps. I dont remember them 10 years ago , so they are most likely a newer capacitor design ? Regardless, I could actually see Bob checking each cap for ESR before it leaves his place. He's got him a fancy ESR Checker.

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Heck, clean an extra roof this week!

Therer is certainly a direct relationship between the way an old capacitor sounds and the ESR/Q of that capacitor. I have an old Seeburg crossover that sounded terrible. I checked the ESR of the caps and the numbers were real high on both networks. (IE: 2.5, 1.7ohms, etc.) I'm ordering new caps fot those crossovers now.

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Heck, clean an extra roof this week!

Therer is certainly a direct relationship between the way an old capacitor sounds and the ESR/Q of that capacitor. I have an old Seeburg crossover that sounded terrible. I checked the ESR of the caps and the numbers were real high on both networks. (IE: 2.5, 1.7ohms, etc.) I'm ordering new caps fot those crossovers now.

heck JL, If I break down and buy me sum good caps from Bob Crites or DeanG, it will be getting into my Boiled Peanut Money ! You lucky Scoundrel, get you a deal on that ESR Meter, I am soo jealous. I never really checked Parts X Press before, but them Dayton 1 percenters look cool ? I bet old man Crites and DeanG both match crossover caps ? I even have a pic of Bob in my mind, measuring Caps, in between bites of Arkansas Catfish ? IF the Madisound Surplus Poly's do not work out, it will be no big deal, 2 of the 10uf's, in stacks of 3 to make 30uf are simply woofer dump caps. One is the lower midrange horn crossover, so it IS a very important Cap. Oh, I did call Madisound, found out the Caps are only 4 to 5 years old !! So, 3 of them in parallel should be ultra low ESR ... If they do not sound good, and assuming the Solens I ordered for the top of the midrange crossover, and bottom of the tweeter do, I will simply grab a couple more 30uf Solens for the midrange high pass. ERSE has some good prices on Poly Caps, as do Madisound and Parts Express. What Caps are you gonna try JL ?

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I might try some of those surplus polys myself. That said I have been happy with the Solens on previous projects.

Thats good to know JL, never tried Solens on horns before. IF you do decide to break down and spend the 60 cents on the 10UF Surplus Polys, please hook them up to the ESR Tester, and let everyone know what they really are ? You can google TYEE Capacitors, they are out of Fullerton, California. They have complete PDF files on their products, and it looks pretty decent quality.

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"heck JL, If I break down and buy me sum good caps from Bob Crites or DeanG, it will be getting into my Boiled Peanut Money!"

I don't sell parts -- I just build networks for people who don't want to mess with building them.

Oh, sorry about that Dean.

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I might try some of those surplus polys myself. That said I have been happy with the Solens on previous projects.

Thats good to know JL, never tried Solens on horns before. IF you do decide to break down and spend the 60 cents on the 10UF Surplus Polys, please hook them up to the ESR Tester, and let everyone know what they really are ? You can google TYEE Capacitors, they are out of Fullerton, California. They have complete PDF files on their products, and it looks pretty decent quality.

Hey JL, lookey what I just found ? Seems the Madisound Surplus TYEE 10uf Poly Cap is very low ESR ?


Non-Polar Electrolytic vs. Polypropylene Film Capacitors








This isn't what you think! While there certainly are subjective
preferences on these parts, I would like to present to this community
the results of some tests I have performed today. The parts tested are
all currently available, value oriented parts from Madisound,
Parts-Express, or MCM.



-Measurements were made using the HP 4192A Impedance Analyzer
(Calibrated this year).Three measurement frequencies were used: 100Hz,
1kHz, 10kHz.

-Signal voltage was 1VRMS.

-The series equivalent circuit model was used for calculations.

-Measurements presented are the capacitance, equivalent series
resistance, and dissipation factor respectively.



  • 3.3uF Panasonic Polypropylene Film 200V (Madisound surplus)

    0.10 kHz 3.313 uF <0.1 Ohm <0.01% DF

    1.00 kHz 3.306 uF <0.01 Ohm <0.01% DF

    10.0 kHz 3.31 uF 0.005 Ohm 0.1% DF
  • 3.3uF Bennic XPP 250VDC (Which are on sale this month at MCM)

    0.10 kHz 3.313 uF <0.1 Ohm <0.01% DF

    1.00 kHz 3.306 uF <0.01 Ohm <0.01% DF

    10.0 kHz 3.28 uF 0.002 Ohm <0.1% DF
  • 4.7uF Non-Polar Electrolytic 100V (From Parts-Express)

    0.10 kHz 4.989 uF <5 Ohm 1.45% DF

    1.00 kHz 4.826 uF 0.93 Ohm 2.8% DF

    10.0 kHz 4.7 uF 0.264 Ohm 7.8% DF
  • 5.0uF GE Polypropylene 400VDC (Surplus from Madisound)

    0.10 kHz 4.93 uF 0.001 Ohm 0.1% DF

    1.00 kHz 4.92 uF <0.01 Ohm <0.01% DF

    10.0 kHz 4.93 uF <0.01 Ohm <0.01% DF
  • 10uF Madisound Surplus 100VDC

    0.10 kHz 10.1 uF <0.01 Ohm <0.01% DF

    1.00 kHz 10.07 uF <0.01 Ohm 0.04% DF

    10.0 kHz 10.1 uF 0.003 Ohm 0.2% DF
  • 10uF Dayton MPT 250VDC (From Parts-Express)

    0.10 kHz 10.005 uF <0.1 Ohm <0.01% DF

    1.00 kHz 9.98 uF <0.01 Ohm 0.03% DF

    10.0 kHz 9.99 uF 0.001 Ohm 0.1% DF
  • 12uF Bennic XPP 250VDC (Which are on sale this month at MCM)

    0.10 kHz 12.05 uF <0.1 Ohm <0.01% DF

    1.00 kHz 12.03 uF <0.01 Ohm <0.01% DF

    10.0 kHz 12.04 uF 0.001 Ohm <0.1% DF
  • 12uF Bennic Non-Polar Electrolytic (From Madisound)

    0.10 kHz 12.675 uF 3.45 Ohm 2.7% DF

    1.00 kHz 12.12 uF 0.40 Ohm 3.0% DF

    10.0 kHz 11.74 uF 0.073 Ohm 5.4% DF
  • 31uF Bennic Non-Polar Electrolytic (From Madisound)

    0.10 kHz 32.3 uF 1.60 Ohm 3.2% DF

    1.00 kHz 30.5 uF 0.241 Ohm 4.6% DF

    10.0 kHz 29 uF 0.057 Ohm 10% DF
  • 33uF Non-Polar Electrolytic (From Parts-Express)

    0.10 kHz 33.9 uF 1.78 Ohm 3.8% DF

    1.00 kHz 32.1 uF 0.170 Ohm 5.4% DF

    10.0 kHz 31 uF 0.047 Ohm 9% DF


Impressions.

Non-polar electrolytics are pretty lossy compared to polypropylene. I
have always heard that, but never quantified it. Notice how the
capacitance drops with frequency and the dissipation factor rises in the
electrolytic capacitors.



Electrolytics are not very linear with frequency, we see a 10% change
from 100Hz to 10000Hz! (this does NOT imply they cause non-linear
distortion due to this fact, please don't misunderstand). The
polypropylene capacitors by comparison are fairly linear in capacitance
with frequency and most have dissipation factors too low to reliably
measure.



Notice the high series resistance of the electrolytics compared to
polypropylene. This does not seem to me to be a negligible amount of
resistance in crossover design, after all, don't we model inductors with
this much series resistance? I do not have experience with crossover
design software beyond Speaker Workshop, and do not know if any of them
can model the non-linear resistance of an electrolytic capacitor. It
would seem to me that this would be particularly important for midbass
drivers in a 3 or more way. The Qts of the driver-enclosure system will
be affected by this series resistance.



Anyone else care to comment on this?



Regards,

David

























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Here is some more from that same thread. This guy maintains that ESR is not as important as we think.


Quote:



The esr of capacitors isn't so critical because their reactance is
so high at low frequency. For instance 3.3uF at 100Hz has a reactance of
482 ohms so an ohm of ESR doesn't really make much difference. Even at
10KHz, the reactance is 4.8ohms. Not to say it's not important, it needs
to be taken in context and of course, it's the opposite for inductors,
ESR is the essence of inductance.


This is a good point, and one to which I will have to give some
thought. The whole motive behind these tests was to find out whether it
would be preferable to replace some rather large 92.5uf value
electrolytics with film capacitors in the NHT M3.3. These capacitors are
in series with the mid-bass drivers, so it seemed intuitive to use the
lowest ESR available. What I did not consider, as you have pointed out,
is that the ESR is a fraction of the reactance at the frequencies of
interest (100-300 Hz).



Impedance = Resistance + Reactance



Reactance of Capacitor = 1/(2*pi*frequency*capacitance)



Measured Impedance of 96.9uF Capacitor at 100Hz = 16.96 Ohms



Calculated Reactance of 96.9uF Capacitor at 100Hz = 16.42 Ohms



Equivalent Series Resistance = Impedance - Reactance



Equivalent Series Resistance of 96.6uF Capacitor at 100Hz = 0.54 Ohms



Impedance difference due to Equivalent Series Resistance =
100*(1-(16.42/16.96)) = 3.18%



Not as small of a difference as I had originally suspected, but still
gives validity to your point.



I would like to simulate this non linear resistance in a crossover
schematic, to see how much error the ESR of a capacitor could introduce
in the frequency response of the filter.



Good day all,

David
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How bout that. The Madisound tested good there. Seems to be so much info out there about ESR and so many differences of opinion about how it affects things that I really wonder what to believe. It seems many experts don't agree on much at all when it comes to audio related technical topics like the affects of ESR or Q on the filter circuit.

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How bout that. The Madisound tested good there. Seems to be so much info out there about ESR and so many differences of opinion about how it affects things that I really wonder what to believe. It seems many experts don't agree on much at all when it comes to audio related technical topics like the affects of ESR or Q on the filter circuit.

Exactly! Al Klappenburger here is doing a test on Tweeter Distortion, and suprisingly enough some tweeters with not so good distortion specs sound great. Me, I don't care how it measures, I care about how it sounds. I tried the same type of new caps to replace the old caps in my E/V Sentry III's, did not care for the sound, so figured I would try some low ESR Caps. If these don't work, I will keep going, until I get my sound. The Sentry III's never sounded Bad with any cap change I have done, they just lost some majic that I know is there. What are you using for speakers JL, and what is the state of your crossover ? Has it been changed out, or had the caps refreshed yet?

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I have Belles with type A crossovers w/ fresh Solens caps being driven by a Sansui integrated tube amp AU-70. When I got these speakers they originally had a type AA crossover in one and a type A in the other. This system I listen to about everyday and it really sounds great to me. Although I'm an experimenter at heart I really don't know if any change will come to this setup for a while. Most people are surprised how good an old RTR machine can sound through this setup.

I also have JBL 2441s over Altec short horns in an active two way system w/ SEP tubes on the upper and SS on the bottom.I swap the tops out with big Dukane 2ft horns and RF7 horns for some active 3 way fun.

I'm refreshing JBL and the Seeburg crossovers for various projects/experiments.

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I have Belles with type A crossovers w/ fresh Solens caps being driven by a Sansui integrated tube amp AU-70. When I got these speakers they originally had a type AA crossover in one and a type A in the other. This system I listen to about everyday and it really sounds great to me. Although I'm an experimenter at heart I really don't know if any change will come to this setup for a while. Most people are surprised how good an old RTR machine can sound through this setup.

I also have JBL 2441s over Altec short horns in an active two way system w/ SEP tubes on the upper and SS on the bottom.I swap the tops out with big Dukane 2ft horns and RF7 horns for some active 3 way fun.

I'm refreshing JBL and the Seeburg crossovers for various projects/experiments.

Solens, Huh ? This will be my first go round with them on horns, since i ordered em from madisound to go along with the Surplus Polys. I have owned about every Klipsch Heritage speaker known to man, my personal favorites were the original Forte's. I re capped them with all ERSE Polys, and they were fantastic, just too small looking in my large room. I currently have Cornwall 2's I re did, but along came the E/V Sentry III's, and the Cornwall 2's have been pushed out of the way. I have 5 other pairs of speaker besides these, including big Polk SDA SRS 2B's, JBL S 412 P's, Tannoy D 50's, Vintage Pioneer Horns, and some bookshelf Pro Monitors, cant even fremember what they are, LOL I JUST sold my B&W Matrix 801's. I also just got finished really listening to the E/V Sentry III's. I placed the old caps back in them, except I used 2 new 1uf Rat Shack Mylars combined to make 2uf on the ST 350 tweeters, guess what ? They are not accurate anymore, musical yes, accurate, no ! The 36 year old high ESR caps are veiling the big E/V's, softening the sound, kind of like a Jalapeno Pepper coated in Honey. I have gone into home theatre in a big way, and crave the efficiency and jump factor of a big horn speaker. I am hoping the Electro Voice Sentry III's will be the speaker I seek, when I am finished with them. The Cornwall 2's were a big disappointment. If I was just listening to 2 ch, the little Tannoy D 50's are probably my favorites. They are ungodly musical little bastards, image like no tomorrow, and there is just "something about" the Tannoy dual concentric driver that sucks you into it's game. I cross them over at 80 hz with a crossover done in the digital domain, and they will play pretty loud. They are tiny, 1/2 the size of the small Forte's, so look even more stupid in my room, but they put a smile on my face. The JBL S 412 P's are a real sleeper of a speaker, they just do not have the last degree of wild 3 dimensional imaging of the B&W 801's or the Tannoys. They image more like Klipsch Heritage Speakers do, a wall of sound, but no real 3 dimensionality to write home about. But they are very musical, do well on voice, and have a well matched center channel speaker i also own to make their case. If the Sentry III's do not get to where I want them to be, I will probably just go back to the JBL S 412 P'. I was very happy with them as a good compromise between musicality,, and home theatre performance, before the efficiency bug bit me in the azz. You see JL, 2 of my room corners are occupied by what looks like dual overgrown K Horn bass bins.

These are 9 cu ft ported boxes using an EBS alignment, they are 3db down at 14 hz. Each box has a 15 inch Cadence Wild Beast downward facing driver firing through a slot formed by the floor/wall/corner intersection. These 4 ohm super long x max drivers have true 2500 rms on each of them at 91 db efficiency. I had a pair of HSU subs, replaced em with a pair of SVS Ultra Cylinders, and built these to beat the SVS. They are capable of truly frightening bass JL, and most of my speakers are simply unable to "play over the top" of them for long, if at all. Horns are my only hope for a true "scare the chit out of you" home theatre system. It has been an interesting journey so far, and I so much want the E/V Horns to work out, I really do.

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Wow, you've got the low end covered I'd say. If you can score a pair of fully horn loaded speakers. I think those are the most musical. Some 2" drivers/horns like the 2441s or similar can really "blow your head off." and yet still be crystal clear. Surely those could keep up with your mind bending bass bins.

I'm really partial, nothing sounds as good as a horn loaded speaker.

I'm surprised you didn't like the 801s? Those are pricey and a well thought of speaker.

While doing all the cap swapping I just wonder if your comparing the Sentrys with the 801s instead of the way they "used to sound" vs the "new cap sound". Just a thought. Very hard to compare cap changes in a speaker set + speaker swaps along the way. In other words, maybe the Sentrys weren't that good from the start. Lets face it, usually the best a pair of speakers sound is when you first give them a listen.

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