Measuring A Capacitor

Please reread your own post. You did say it would be amplified 10,000 times. And it would not be "a very large transient." it would be a slight pop that clipped it for a minuscule amount of time. Look, it happens all of the time in the winter. I walk across the room to change the record and when I touch the tonearm I feel a discharge which creates a pop in the speakers. Over and over and over and over again. The tweeters still work just fine.

please reread my post. You evidently don't understand electrostatic discharge. You don't have to have a spark like the kind that jumps from your hand to the light switch for a discharge to occur, Most are never felt. For it to occur it would have to at some point jump the gap. When it did, however small it was, it would drive the system to clip for a instant. There is no way in the world that a very brief pop from the system would take out a healthy tweeter. It is however not unlikely that a static discharge through the input devices could damage one of them and that is the point that we both missed earlier. As a matter of fact, turning off the system would do nothing to protect those input devices. The static discharge through them would be the same no matter if the system was on or off. The only protection in that case would be to follow safe ESD practices.

You seem to be one of these people who loves to give advice but can't stand it when they are offered it. I stood corrected and admitted that my advice was bad because a static discharge into the input could damage the system by damaging the input devices. Suck it up and admit that this same pop would never take out a tweeter.

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You did say it would be amplified 10,000 times.

I neglected to say the obvious, which is that it would be less if the system were clipped, which will most likely happen.

And it would not be "a very large transient." it would be a slight pop that clipped it for a minuscule amount of time.

It would be very brief, that has nothing to do with its amplitude, which is what the phrase "very large" refers to.

I walk across the room to change the record and when I touch the tonearm I feel a discharge which creates a pop in the speakers.

The static is not going directly into the signal path, as it would be in the scenario I hypothesized. Big difference!

There is no way in the world that a very brief pop from the system would take out a healthy tweeter.

Let's say that it was so brief that it lasted only 50 microseconds (a single period at 20kHz). We are both agreed that its amplitude could be full power, to the clipping level of the amplifier. Say that is 100 or 200 watts. Will a single cycle of 20kHz at 100 or 200 watts damage a tweeter? I don't know, but it certainly sounds like a cause for concern. It certainly will not damage it via thermal effects, but the concern would be the over-excursion it would result in. If you are certain that it will not harm the tweeter, please provide a link to some documentation or technical rationale that is more persuasive than your simply saying it will not.

You seem to be one of these people who loves to give advice but can't stand it when they are offered it.

If you knew me better you wouldn't say that.

Basically, this thread has become unpleasant because you chose to describe my "err on the side of caution" advice by using the word "paranoid," twice. The fact that you said what could easily have been said in a constructive manner, in an inflammatory and disrespectful manner instead, would seem to say something about what kind of person your are.

You'll have the last word, because I don't intend to devote any further time to this utterly pointless and unnecessary argument.

-- Al

The hum is finally gone! The ultimate fix was a simple one. All I had to do was flip the preamp plug 180 degrees. I thought I had already done that. Live, and learn I guess. Now I have about 5,000 LPs that are waiting to get played... You all know what LP stands for, don't you? Most people think it mean Long Playing, but it really means "Licorice Pizza".

Thanks to all who contributed to my affliction with vinyl.

Lee

Outstanding! Phono hum is a very common problem, as others have noted above, so I'm sure the information brought out in this thread on the various possible approaches will prove useful to others in the future. Glad it worked out.

Regards,
-- Al

An update - This morning, the hum had returned, so I retraced my doings of the day. It turns out that the cause of the hum wasn't plug orientation, like I first thought. But rather, it was airborne RF interference caused by my amp. As long as there is a piece of foil between the amp and the cables going into my preamp, everything is fine.