[Folsom]

Electric charge, Mr. Destroyer, electric charge....

By definition current is the rate of flow of electric charge, it cannot be "stored".....

And while current does not flow "through" a capacitor, it will "flow" through its *terminals*....

Right right, charge, whatever. You still can't discharge through a capacitor. Only across it, or if it fails. You'd have to touch the line and ground at the same time to get a discharge, and at that point you'd already be sorry with or without a capacitor. 

[iluzun]

To follow up....  I've tried out several pre. of .22s. & am very happy w/the results.  Mundorf S/O/G, sound
colorful & vibrant in the miss, Clarity MRs neutral, extended at both ends, & the 'teflon' Sonicap Platinum
the most natural, detailed, even handed presentation.  As noted, haven't tried the CuTf V-caps but I am
'interested' to say the least.  E ended up putting the Sonicap on my amps outlet & my dac can be fed by
either another Sonicap or a Clarity.  The digital portion is preceded by a CMC, as is another pr. of outlets
for my pre, turntables, ext...  I havn't done anything to those yet. 

As Pete Townsend noted.... 'Just fiddlin' about'.... 

Didn't take long to try this out as I was familiar each caps sound as they had all spent time in my preamp.

Amazing to me how each cap totally colors everything downstream, even without being in the 'direct signal path'.

Makes me want to rip the Dueland Cast out of my preamp and.......

This is all preceded by 3 dedicated 10g lines to a sub panel.  Outlets on each I believe are silver, cryoed, 'zapped', Wattgates.

Run gold Isocleans on 3 10g dedicated downstairs in another rig also; no conditioner on such...

I suppose next I'll have to try doubling up the cap value on the amps outlet to see 'what happens'.

So far...  dynamics & detail from a blacker background, very evenhanded across the frequency range.
Large spacious musical soundstage w/better separation & textural resolution.  I think I know where this is going...

Me likey....   

[BobM]

I recently pulled my crossovers out of my speakers, built a separate box for them and recapped them all. In one section (for the tweeter) I needed 70uF of caps in parallel. Well, I found a combination of caps to give me the best blend of the sound I was after, rather than using 7 x 10uF of the same brand. I used Sonicaps, Spragues (the original cap in the crossover), Auricaps, a Russion PIO and a .1uF V-Cap Teflon bypass. I've got transparency, bloom, tightness, extension, midrange magic and air, all without fatigue.

[iluzun]

Just a follow up note....  I've ended up w/Mundorf Silver Gold Oils on the conditioners outlets.  These r caps
I had lying around but had never considered using in such an application.  To say I'm pleased w/the results
would be an understatement.  Smooth, detailed, extended, fast, musical, transparent, spacious & clear.  Ultimately they sounded best when used on each of the 3 sets of outlets  powering  dac, pre, & amp. alone;
not mixed w/other brand caps,  I've a 3.3 on each amp & pre, & a pr. of .22s on the dac.  Everything is just so
darn listenable.  I do believe I like the S/O/Gs more used as such than I ever did running them as coupling
capacitors in tube amps or preamp in isolation.  There is a 'coherence', as of a singular cloth, even though
downstream there is a mix of Modwright teflons in the Transporter, Duelands Cast in the pre, ??? in the Yamaha A-S2000, ect...  I shoulda done this years ago.... 

[horchai]

just my 2 cents experience. I have used small (0.1, 0.22, 0.47) and large values of (3.3, 4.7, 5.6, 6. of mundorf supremes, SIO, SG, SGOs before across ac outlets. My experience is that small values work best. With large values, it seems to round off the sound a little more, make it darker and not as focused. Though they are not x-rated caps, so far so good, none has exploded before but still there's a risk of it happening. so user beware. 

[wakibaki]

just my 2 cents experience. I have used small (0.1, 0.22, 0.47) and large values of (3.3, 4.7, 5.6, 6. of mundorf supremes, SIO, SG, SGOs before across ac outlets. My experience is that small values work best. With large values, it seems to round off the sound a little more, make it darker and not as focused. Though they are not x-rated caps, so far so good, none has exploded before but still there's a risk of it happening. so user beware.

Q. If a 6uF capacitor is connected across the UK mains, how much current will flow?

A. 0.45 amps (rms). Nearly half an amp.

It is certainly true that no nett DC current flows but if 'no current flows through a capacitor' then there wouldn't be any point in using one in a filter.

It's one thing to mess around with the voltages inside a computer, or even the +/- 30~40 volts in your average solid state amplifier, but it is seriously dangerous to modify devices operating at mains voltages, if you don't know what you're doing.

Most of you guys have families who you are exposing to these dangers.

You are going to get somebody badly burned or killed one day.

[Speedskater]

Also when you unplug the unit, any capacitor across the power line can retain a voltage up to the line voltage peak!

[Folsom]

More dangerous than working on a 600v tube amplifier?

There are options for discharging if you think it'll be too risky to just unplug from the wall with a piece of equipment on, whenever you unplug it.

[Speedskater]

"DofS" your are mingling different ideas again.

a] When one works inside a 600V chassis, one is very careful! (I hope)
    When one moves an un-plugged unit, one is not expecting a high voltage shock!

b] In the above AC circuit example,  the continuous AC current is 0.45A.

c] When one designs a unit with a large capacitor across the AC line, one places a dis-charge resistor in parallel with the cap or caps.
   The would be a resistor specified for high voltage.  With a value of about 1meg.

[wakibaki]

More dangerous than working on a 600v tube amplifier?

Capacitors hold .45a charge (at 120v), not current flow, in your example.

There are options for discharging if you think it'll be too risky to just unplug from the wall with a piece of equipment on, whenever you unplug it.

This is arrant nonsense.

Current is measured in Amps. Charge is measured in Coulombs. You are one of the worst offenders, you have no idea what you are talking about, and you have no conscience about endangering someone else's health or even life. Mains voltage will kill. Get a grip.

w

[Speedskater]

I should note that the above charged capacitor most probably won't electrocute a healthy person.  In the high school electricity lab, we would charge up caps and chase each other around the room.  But your reaction to the shock can cause accidents.

[Speedskater]

In Ott's book, the chapter on filters limits the 'Y' capacitors (line to ground) in a US system to 0.01uF.  In the 'X' capacitors (line to line) the typical range is 0.1uF to 2uF.

[Folsom]

This is arrant nonsense.

Current is measured in Amps. Charge is measured in Coulombs. You are one of the worst offenders, you have no idea what you are talking about, and you have no conscience about endangering someone else's health or even life. Mains voltage will kill. Get a grip.

w

I'm well aware that capacitors are not rated with amperes, I'm merely pointing out that there isn't current flow, rather the amount of current that would flow is turned into a charge (it remains a potential), then released out of phase to the 50hz AC signal. It is an important distinction because of safety rating concerns Speedskater has brought up.

Telling people that mains voltages will kill isn't a new thing. Anyone dealing with electricity in a DIY fashion should be, and usually is aware. The point is we don't stop making things because it could kill us, we just pay respect to that fact. You are suggesting to the people on here that people just shouldn't do anything at all. I wouldn't cross the street if I lived like that. I firmly believe people are more than capable of learning and respecting things that pose a mortal potential; you just assume they will get killed.

You'd have to be touching the blade of a plug with one hand, and the other with your other hand, to actually get killed in this case. Getting shocked sucks (hence why children try to do it to each other), but if it doesn't pass through the heart it is unlikely.

[Speedskater]

No, NO, NO !
In the post #25 example,  0.45 Amps is flowing day and night.

[Folsom]

Not through the capacitors. The capacitors will charge, and discharge out of phase to the 50hz used in Europe; available to the load. That is when connected across line and neutral. This happens day and night if the device is turned on, or is part of a power distribution that doesn't turn off.

Nothing goes through a capacitor. They made the symbol for it look like this for a reason.

[wakibaki]

OK. Take a 6uF capacitor. Hold one terminal. Touch the other side (terminal) to a point in a circuit at mains potential.

Come back and tell me nothing flows through it.

w

[Folsom]

Very funny. They still don't go through it.

Capacitors on mains are no more dangerous than mains themselves, they just can have a charge briefly after a device has been unplugged. But there are discharge options. Unfortunately the 1m resistor isn't a good one because it can take a long time with higher capacitance. 

[*Scotty*]

There's is no diplomatic way to say this, AC will pass through a capacitor. If you doubt this, take an ammeter and place it in series between the cap and neutral. You will measure a current flow from line to neutral. The  fact that AC will pass through a capacitor is what makes it possible for a tweeter function when a capacitor is used in a crossover inline
between the tweeter and the amp.
Scotty

[wakibaki]

You'd have to be touching the blade of a plug with one hand, and the other with your other hand, to actually get killed in this case. Getting shocked sucks (hence why children try to do it to each other), but if it doesn't pass through the heart it is unlikely.

So you accept that you could actually get killed.

Anyway, you're wrong about the 'blades of the plug' bit, all that is necessary for the current to pass across your chest is for the leakage path to be through your other hand, rather than through your shoes. If your other hand happens to be holding a piece of grounded equipment, and you're wearing rubber-soled shoes, such as trainers, then it will be.

You're just trying to use oversimplified explanations to excuse your irresponsible attitude. Children and babies are exposed to dangers from ill-conceived modifications to mains-powered equipment. How do you imagine you would feel if a serious accident occurred? The fact that it may be unlikely does not make it impossible, what would make it impossible would be to refrain from making modifications to the mains inlet circuitry of domestic equipment if you're not competent. You're not, and anybody who is reassured by your posts is ill advised.

[Folsom]

There's is no diplomatic way to say this, AC will pass through a capacitor. If you doubt this, take an ammeter and place it in series between the cap and neutral. You will measure a current flow from line to neutral. The  fact that AC will pass through a capacitor is what makes it possible for a tweeter function when a capacitor is used in a crossover inline
between the tweeter and the amp.
Scotty

AC flows in the circuit a capacitor is in, as it builds a charge or releases it, but no current goes through it. Anything that goes through it is considered leakage.

Capacitors get used as DC blockers because nothing passes through them, yet the affect of collecting a charge will appear like current flow to the rest of a stereo, for example. They are not perfect in this however, as their values tend to change some as this all is happening. But that is in series, where the capacitor acts like it is imitating the AC signal; the properties of a capacitors behavior allow AC signal operation without passing current. Here is a tid bit on some of what we've been talking about. I'm not sure what else could help explain this...

I'm well aware that capacitors can discharge, and operate in congruence or 90* out of phase of AC mains, as if they pass current through them, but that doesn't change the fact that none actually does go through them. Leakage raises different concerns because you get a potential where you don't want it in the case of Y capacitors; luckily common amounts of leakage with capacitors isn't enough to be concerned about in our applications.

You are just as likely to get killed from any regular power strip, as you are something with capacitors in it. That is unless you don't make a discharge option then you have at most about two minutes that any amount of capacitance used wouldn't dissipate in. Also I noted it is unlikely, not impossible, with accidental touching of the blades on a plug but capacitance isn't the issue, it is AC mains. You can come up with dozens of ways to kill oneself, but it remains true that it must pass through the heart. The same dangers are true regardless of capacitors.

I don't feel irresponsible at all. No child or baby is at any more risk than they were before. Also I don't feel you are qualified to say who is competent and not, given your authoritative attitude towards this you appear as nothing more than a condescending thug. Frankly I don't feel the close minded approach of telling everyone that they are incompetent to learn, and that those of some sorta (often false) authority on safety that you deem appropriate are the only ones to be trusted, is a very appropriate attitude for a forum section that is about DIY projects. That of course doesn't even begin to cover the egotistical notion that your idea of safety is everyone else's idea of safety; I'm sure members of this forum enjoy extreme sports and such. Sometimes what we want supersedes varying amounts of all possible safety. Funny that I say that, because I don't feel unsafe at all about using capacitance in AC application because I respect the possibilities and am willing to provide discharge options for safety.

There are ways to express your opinions about safety concerns without being condensing or trying to exert authority; to be respectful of others.