The Capacitor Abyss-yes, can it get any better?

Blue Shadow

Waiting for Vintage Gear from this century
Thank you Binkman for your title to this new topic...maybe forum on AK.

Let's get this party started. There are many opinions on this so lets keep it on topic or this thread (or posts) will vanish just like wire discussions.

Keep on topic, avoid calling out, state your opinions and keep it clean or we will never have an Abyss in which to party.

They make a difference.

They break in.

They have varying costs.

I like to use the ones that look good. Black and Gold is nice. Wish the Silmics were prettier, brown and not quite white visually just doesn't pop.

Now if I had the testing gear, knowledge base and such of well let's pick someone that has talked about caps recently, ConradH, I would be able to add more. An understanding the specs is something many (should I say most) here do not have in the toolbox and selecting, purchasing (costs) and installation are something that many do. Be nice to have a forum to discuss it...well at least have a knowledge base bump by those in the know.

Added with the edit:

I have been contacted about this thread and there is interest in presenting what capacitors are, materials used and other information. I read the definition and it was too complicated to put out there as the first indication of what a capacitor is so I will put a definition here: A capacitor is a passive electrical device that is used to store an electrical charge. In a simple form it consists of two conducts separated by an insulator. This is information from a web search of capacitor definition. I read a few and put something down.

There was also discussion of citing your information. When you have something technical to present, citing helps as we can go to that location and glean more information. Conrad has done that in his post on page 2 about the early days of capacitance measurement.

I would like to point out that Wiki has a good run down on caps: http://en.wikipedia.org/wiki/Capacitor

Although this thread is a general location for discussions about caps, we are probably going to give it an audio slant and not necessarily an automotive energy recovery slant. But the wiki article does cover many ideas we can expand on and the math involved can probably be ignored for almost all the discussions. I mean who still knows differential equations and integrals anymore? Like we ever really learned it.
 
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Hell I'm just wrapping my head around test equipment and do I need it.. throw in a scope and the rest of the stuff.

(I have always noted this is not a cheap hobby)

takes a long time for forum to get built into a website and some bucks...

I kinda like it on the fly myself in the DIY forum. So far?

DIY is cap abyss!! Motor abyss, transistor abyss, failed marriage abyss.. really we got a tube audio section and they come here, too.

(answers by new posters; I think expect some instant response to flip a quick buck? I'm not into that.)

Just my feelings on the topic.

bink
 
While DIY people always choose the well-known brands, I often wonder if less regarded brands such as Jamicon really are bad performers.
Some repairmen go cheapest as possible, as they argue the capacitors they put in now will almost for sure outlive the equipment they put it in anyway.
Of course, this is not the goal for people restoring old equipment wanting to give it a "real second life".

BTW is this thread about all capacitors or aluminium electrolytics only?
 
Without getting into your starting assumptions, you can search for "ESR meter" in "Electrical and Test Equipment" on ebay and get quit a listing of reasonably priced test gear. I have not used any nor have I any affiliation.

Shelly_D
 
Based on my posts, people probably think caps are all I think about. Not at all true, but because I collect old GR test equipment, and they made a lot of capacitance bridges, I test a lot of caps. I test what comes out and try to correlate it with problems and sound, and I test what goes in just for peace of mind.

Anyway, today's discovery involved a beautiful little Bogen AP200 tube amp that I'm fixing up. Though I change out almost all electrolytics as a matter of course, in the interest of originality I leave the ceramic discs alone. After all, they don't age or drift. Not my first choice for coupling caps, but hey, it was the 1960s.

Well, turns out they can age and drift. One of the 0.01 uF parts was about 0.007, and at least one of the 0.05 parts had very high losses. Changing them to nice films got the frequency response back where it should have been.

Morel- you just can't trust any rule of thumb, gotta measure.
 
The need and desire for test equipment depends on how much of this stuff you do. For the price of a single old used cap bridge, I can buy a lifetime supply of brand new top quality small radial caps.

IMO, a signal generator and scope are the #1 items to have. Toss in a computer and sound card and you have a spectrum analyzer and distortion meter for free. If you run Visual Analyser, you also have a very good cap meter, though you do need to solder up a simple circuit/adapter for the task.

There isn't a good single cap meter solution for every need. If you do tubes, you need something that can measure high voltage leakage. That means either an expensive GR1617A or an antique/vintage service bridge that needs to be rebuilt.

The bridges that are the best for small film caps tend to have a maximum range of 1.1 uF, not too handy for 90% of what we do.

The most common portable bridge (GR1650) maxes out at 1100 uF, still too low for big filter caps. Some go higher, but are real boat anchors. Actually, the 1650 is a bit of a boat anchor by modern standards.

The best bang for the buck is a digital bridge, either an old GR1657 or one of the new $25 chip jobs from eBay. Tenma also has one or two that aren't bad and don't cost an arm and a leg.

Still, until you have that scope and sig gen, everything else should be secondary. It's impossible to know you've done a good job with a receiver or amp rebuild with a scope and sig gen.

One odd thing I've seen over many years of design and troubleshooting is that I get a lust for some piece of exotic test equipment, knowing it will reveal new information and make life easier. Often that equipment ends up teaching me something new, but then equipped with that knowledge, the need for the equipment disappears! It shows me how some class of component tends to act, and gives me the elusive rule of thumb, so I don't need to make more measurements. Or, it sits on the shelf waiting for some once-a-decade special task.
 
Conrad, I am interested using this "sound card solutions". I am curious about noise or bad measurements because of the grounding or other disturbance out of the computer and because the usually poor minijack connections. Would it be best to use something they call an "external" sound device using usb or so?
 
Thinking; 'Conrad the abyss of electronic experience.... reminds me of capt. kirk asking 'scotty" (Conrad) for more power' LOL..

"capt she's running at warp now at 15v caps.. I don't know if she'll hold warpII"

:smoke:
 
Dammit Jim, I'm a hifi doctor, not an audiophile.
Captain, I'm detecting a 12 uV imbalance in the bridge signal.

gslikker- My experience is very limited in the PC area. I use an ancient Emu 0202 for an interface, and sometimes the built-in Realtek or whatever motherboard stuff. Interference hasn't been a big issue, though I sometimes have to play with the ground lift switches on the bottom of the Emu. I try to keep everything plugged into the same power strip- there's one particular setup I do that has things plugged in on both sides of the room, and that one is always problematic, with hum and noise issues.

Visual Analyser is free and if you haven't looked at the LCR function, it's pretty cool. The learning curve on much of the program can be steep if you haven't used the traditional physical instruments, but if you have, the features are pretty amazing.
 
Thank you Binkman for your title to this new topic...maybe forum on AK.

Let's get this party started. There are many opinions on this so lets keep it on topic or this thread (or posts) will vanish just like wire discussions.

Keep on topic, avoid calling out, state your opinions and keep it clean or we will never have an Abyss in which to party.

They make a difference.

They break in.

They have varying costs.

I like to use the ones that look good. Black and Gold is nice. Wish the Silmics were prettier, brown and not quite white visually just doesn't pop.

Now if I had the testing gear, knowledge base and such of well let's pick someone that has talked about caps recently, ConradH, I would be able to add more. An understanding the specs is something many (should I say most) here do not have in the toolbox and selecting, purchasing (costs) and installation are something that many do. Be nice to have a forum to discuss it...well at least have a knowledge base bump by those in the know.

I've read your opening post about six times, I have no idea exactly what it is you wish to discuss. . .

Perhaps you can explain it in a simpler way. . for us thick headed bunch :sigh:
 
Ah, Capacitors, really.

Maybe those that know can talk about what is important for PS, coupling and bypass caps and those that don't know can learn. Folks can talk about the sonic differences they have found using different caps.

Whatever comes to mind about caps. It seems this is an issue that is frequently discussed on all the forums and here is a place to take that discussion so deep it is moves to the dark side where no light reaches the subject.

But with an abyss to fill, we can discuss caps ad nauseam and enjoy the ride.
 
Hello, well that was the sound of Roger's Wah Wah Rabbits. You heard them eating endive there. That's very cheap at this time of the year. But now here in Willesden Green...yes, brrr...it's a bit chilly, but no matter, because here comes a gentleman and we're going to talk to him about capacitors!

Excuse me, sir, would you mind talking to us about capacitors?
Do what?
About capacitors.
capacitors?
Yes.
Cause I've got plenty at home.
Good grief.


parap. from The Bonzos "Shirt" 1969
 
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I measure all caps before using them and I have found the occasional bad one, prior to being used in a circuit.

But, I have yet to experience, measure or anything similar to determine capacitor break in. This is because they do not break in.

In regards to quality... there's bad caps and the rest. I don't use the cheap, nasty caps from China, but I do not go out and purchase the top end "musical" capacitor. Your average, reputable brand capacitor is more than adequate for audio purposes.
 
In the spirit of this thread (and in the hopes I might learn something) I will ask a loaded question. How does one quantify one cap sounding better than another? I read that so many folks think the Silmic IIs sound the best. Is there some sort of measurement to give the claim merit?
 
In the spirit of this thread (and in the hopes I might learn something) I will ask a loaded question. How does one quantify one cap sounding better than another? I read that so many folks think the Silmic IIs sound the best. Is there some sort of measurement to give the claim merit?

In things like this you have let your ears be the judge. :yes:
 
Yes ^

Capacitance is capacitance. Regardless of construction and presence, or absence of exotic materials, a 10uF capacitor will measure 10uF (within their respective tolerances) - whether it is oil filled, paper, paste or whatever material.

ESR can be different between the various types of construction and one usually goes for the lowest ESR possible.

Other than that they're all pretty much the same and will operate the same in their intended purpose.

So it does come down to your ears. Whether that is because you really can tell the difference or you have fooled yourself there is a difference is immaterial. Debate rages endlessly over this vexing question and we are not here to create another pointless, heated shit fight. Save that for home or work - where it belongs :)

Our audio hobby/obsession is an enigmatic beast. We share so much, and yet we have our own very personal tastes. Hard science has built the systems to enable our soft engineered brains to generate emotion.

So the best thing is to let your ears decide what sounds best to you, and don't get too defensive, or offensive, if your perspective is challenged.
 
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