You cut the ends of both threaded connectors off with a saw or an angle grinder. Then on one end cut the folded lip of the casing off with an angler grinder. You can pull the innards out then. Get a polypropylene tube and pot them in there with polyester resin.
Getting rid of the steel case and using plastic will get rid of a source of eddy currents and therefor reduce ESR pretty drastically.
Getting rid of the steel case and using plastic will get rid of a source of eddy currents and therefor reduce ESR pretty drastically.
Hi RajkoM,
Okay, that sounds like a reasonable thing to do in that case. I'm use to the tightly wound and impregnated Polypropylene capacitors, and polystyrene types too.
Hi schiirrn,
-Chris
Okay, that sounds like a reasonable thing to do in that case. I'm use to the tightly wound and impregnated Polypropylene capacitors, and polystyrene types too.
Hi schiirrn,
I hate to tell you this, but ESR in signal coupling capacitors is meaningless, pointless. What is critical is DA, or dielectric absorption. Having a low DA really makes a difference in high impedance circuits. If you have an ESR meter, that was money wasted. Generally speaking, a filter capacitor will measure poorly with DA. However you are much further ahead to look at the waveform across the filter capacitor.
-Chris
Thanks for the breaking news
I didn't say it mattered, I didn't say the whole operation made any sense.
And thanks for the hint about meters, i'll ditch all my LCR bridges that display ESR. The type of dialectric influences DF. Now go check the formula for DF and tell us how what you find there doesn't matter.
Hi schiirrn,
Well, my comments are for everyone who reads the forum, not just you. However, what I mentioned should have made perfect sense to you since you have proper equipment. You just didn't know what to look for it seems.
DA is the inverse of "Q". ESR is actually not nearly as important as some people think in signal circuits. It's only applications would be in power supplies and crossover networks for speakers in audio land. Also mind what frequencies you take your measurements at. They should be in the frequency range the capacitor(s) would be subjected to.
Don't fear, we are here to assist if this confuses you.
-Chris
Well, my comments are for everyone who reads the forum, not just you. However, what I mentioned should have made perfect sense to you since you have proper equipment. You just didn't know what to look for it seems.
DA is the inverse of "Q". ESR is actually not nearly as important as some people think in signal circuits. It's only applications would be in power supplies and crossover networks for speakers in audio land. Also mind what frequencies you take your measurements at. They should be in the frequency range the capacitor(s) would be subjected to.
Interesting view. My HP / Agilent and Keysight meters display a variety of characteristics. I wouldn't dream of "ditching" them. Maybe you can save your meters by switching to the appropriate mode when measuring signal capacitors? You might have to read the manual to accomplish that feat.
Don't fear, we are here to assist if this confuses you.-Chris
Looking at a typical SE 2A3 type 50 300B amplifier etc , Vap would have the 3db point very low for example for a 200K grid to ground resistor on the second stage would require a .4uf capacitor?
Vcap recommends below
Coupling Capacitor Calculator by V-Cap
We recommend using a -3db point of 1/10th of your desired low frequency response. For the Human beings with audio systems manufactured on Earth, that would be 1/10th of 20 Hz, or 2 Hz. If you enter the number "2" into the -3db frequency field, the capacitor calculator will automatically calculate your optimal value so you will have great sound from 20 Hz and higher.
Vcap recommends below
Coupling Capacitor Calculator by V-Cap
We recommend using a -3db point of 1/10th of your desired low frequency response. For the Human beings with audio systems manufactured on Earth, that would be 1/10th of 20 Hz, or 2 Hz. If you enter the number "2" into the -3db frequency field, the capacitor calculator will automatically calculate your optimal value so you will have great sound from 20 Hz and higher.
The Russian .1uf teflons are superb. They are FT-3. I just installed 2 in each of my 60 year old Eico 20 watt amps. The opening up of mid-range detail is incredible. The bass is more immediate and defined. I wrapped a pair in foam for a side-by-side and that seems to speed up the sound improvement.
When I stream classical now from the Berlin orchestra I can hear amazing details in the music along with a kind of blooming general sound attribute.
Same benefits with jazz played from stored CD files. I did not hear a lot of these nuances before--not audible at all previously. I did not experience the extended break-in problems so often discussed. They were way better then orange drops right out of the box, and are still improving.
When I stream classical now from the Berlin orchestra I can hear amazing details in the music along with a kind of blooming general sound attribute.
Same benefits with jazz played from stored CD files. I did not hear a lot of these nuances before--not audible at all previously. I did not experience the extended break-in problems so often discussed. They were way better then orange drops right out of the box, and are still improving.
Or perhaps, and this happens quite often, you simply prefer the sound of the unbroken caps. Once they break in you will probably hate them
So far it is 100 hours on 2 of the amps and about 60 on the other 2. I have literally been transfixed by the incredible improvement in nuanced musical detail. I’ll post an update if there is any noticeable change in this trend. So far I wouldn’t trade this 75 dollar improvement for anything.
I just installed a pair of Russian K-75 paper in oil capacitors in coupling position in one of my EICO HF-20 [6L6] amps, and am running a subjective listening test side by side with another HF-20 with Russian FT-3 Teflons. Just 3 hours in, but so far the paper in oil babies have a very sweet mellifluous sound and play out quite evenly top to bottom with a bit of a subdued higher frequency response. It will be fun to log some serious hours in this test mode. I am hoping the PIO develop the kind of stunning mid range tonal separation that the Teflons are providing. The paper in oil caps cost about $4.50 each.
My favorite one. Cheap and looks/sounds really good.
MIFLEX KPCU Capacitor, 0.1uF 600Vdc, Copper Foil Paper/Polypropylene in Oil
Do not go for this al cheapo caps - this is the real thing:
https://www.amazon.ca/Original-0-01uf-10uf-300volt-600volt-Immersion-Capacitor/dp/B07SFY9MMF
https://www.mouser.com/ProductDetail/Panasonic/ECW-FD2W104JB?qs=9JuRDuJWUh9gA5L/vd3B7w==
I’d buy this and a couple 6packs of beer.
I’d buy this and a couple 6packs of beer.
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