sunfire signature has no earth/ground?

[TNRabbit]

Ah....didn't realize the cord had been modified. My apologies.

...but you still come across as pompous~

[stereo_buff]

Who cares? TweakyDude audiophiles sure don't, and I doubt they would pay much attention to the safety advice, even when true. The unit power supply, by design, does not utilize a ground and improper grounding will cause common-mode problems. Bob P can ground his unit and anyone else can 'take their life in their hands' if they so desire, at their choice. In the USA, the low side of the line is connected to ground at the panel, so barring strange occurrences, one side of the power line is effectively at ground (or some other very low potential) anyway.

I do have a technical background.

[angelod307]

Hey angelo -- if you're going to quote me, put *MY* words inside of the quote. It's not fair to put *YOUR* words inside of the quote and attribute them to me. You lose credibility when you do that.

You are really killing me on this. That is were i am lazy. You know, i know, we all know who wrote what. Please do not take this as i do not think you know anything, because you are obviously well read , informed and educated. Now for practical.

[angelod307]

Whatever ships out of sunfire overseas is then going out as a us product. I have way to many certification manuals that sunfire had to get to be compliant. If the amp is a us product, then modded by a third party for overseas use, then i stand corrected. If it went out that way from the factory, i hold my ground. I mean to say i have books of eco's and what not for the sunfire stuff and did skimmed through them. I will look later at the schematics for the euro sunfire amps and get back on this. The transformers are different if i recall correctly as i saw a different number for 230v. So i am kinda curious as to how they made a american amp into a euro one without the factory doing it. Sold the transformer after the fact perhaps.

[Snoop65]

Ah....didn't realize the cord had been modified. My apologies.

...but you still come across as pompous~

I feel you Gary. There is a little "tude" there.

[bob p]

Who cares? TweakyDude audiophiles sure don't, and I doubt they would pay much attention to the safety advice, even when true. The unit power supply, by design, does not utilize a ground and improper grounding will cause common-mode problems. Bob P can ground his unit and anyone else can 'take their life in their hands' if they so desire, at their choice. In the USA, the low side of the line is connected to ground at the panel, so barring strange occurrences, one side of the power line is effectively at ground (or some other very low potential) anyway.

I do have a technical background.

People who don't understand the problem don't have reason to care.
People who do understand the problem have good reason to care.

I don't doubt that TweakyDude audiophiles don't care. If this thread demonstrates anything, it demonstrates that audiophiles could stand to learn a bit more about electrical safety.

The advice that you gave about the low side being connected to ground at the panel isn't going to protect anyone when an internal malfunction causes an amp chassis to go hot, and that's the exact condition that's addressed by the safety standards that require chassis grounding on a Class I appliance.

Don't go relying upon the fact that neutral is connected to ground at the service panel to protect you. That connection won't do anything to help you in an amp design like this one if the chassis goes hot. Because neutral is connected to a transformer and not to the chassis, there is no neutral-to-chassis connection inside of the amp. The neutral-to-ground connection at the service panel cannot prevent your electrocution should the chassis go hot because there is no connection between the chassis and neutral. (As a parenthetical comment: A neutral to chassis connection inside of the amp is a really bad idea -- all that you would need to do is to reverse the polarity on the plug and you'd get a hot chassis!)

The whole purpose of the ground wire is to prevent a hot chassis from ever occurring, which would present an imminent risk of electrocution. Let's consider the two possibilities:

No Ground Wire and Hot Chassis: Chassis remains at an elevated potential of 120VAC, ready to shock you when you touch it, or any gear that's hooked up to it. There is no low-impedance path to ground, so the hot chassis remains hot. You're at risk of being electrocuted if you touch the chassis.

Ground Wire and Hot Chassis: Ground wire on chassis provides an immediate low impedance path to ground, causing the device's fuse to blow as soon as the chassis goes hot, turning off power to the unit and removing the risk of electrocution.

[angelod307]

For those that do not know stereo buff. He is a retired from fluke not that long ago as a lead engineer. Please school the teacher here, this will be interesting as dave knows his stuff better than anyone i know. Bob included.

[fill35U]

Hey, when y'all have a second, I'm thinking about getting an old All-American 5 for my bathroom system. How long of a two-wire extension cord can I use (so I won't have to step out of the tub to tune it) before it affects the sound quality? Thanks!

[bob p]

Don't forget to take the toaster with you -- you might get hungry for a last meal.



Gary, how did you miss the comment about the plug mod in my first post?

[bob p]

The AA5 is an outstanding example of a device that was considered to be "safe" when it was manufactured, but is generally considered to be totally unsafe today, because it has a transformerless power supply and a hot chassis. They killed a signficant number of users. It's a good example of how something that was considered to be safe at the time it was made can be grossly unsafe in retrospect. It's right up there with knob and tube wiring.

http://www.antiqueradio.org/safety.htm

[TNRabbit]

Gary, how did you miss the comment about the plug mod in my first post?

Was looking at all this on my phone; difficult at best.

[bob p]

You just can't make it through the day without a forum-fix, can you?

[Martin1970]

to make a decision that effects his own personal case.

It's actually supposed to be 'affects'
Since you're clearly the smartest guy in the universe, I'm sure you just put that there to see it we were paying attention.

[angelod307]

to make a decision that effects his own personal case.

It's actually supposed to be 'affects'
Since you're clearly the smartest guy in the universe, I'm sure you just put that there to see it we were paying attention.

Fuck martin, it just started getting civil again after i dropped the gas can, so in you come to take your turn with the gas can huh! You are awesome martin, too awesome.

[Martin1970]

to make a decision that effects his own personal case.

It's actually supposed to be 'affects'
Since you're clearly the smartest guy in the universe, I'm sure you just put that there to see it we were paying attention.

Fuck martin, it just started getting civil again after i dropped the gas can, so in you come to take your turn with the gas can huh! You are awesome martin, too awesome.

Actually, I've been guilty of what he's doing far too often. Nothing is more irritating than seeing your own bs in someone else.