Short in amp: house circuit breaker pops, amp fuse does not.

[Dave Curtis, dB AudioTech]

I agree with this and was going to post likewise until I looked at the schematic. I would not fuse the neutral either, but that's how the schematic is drawn: Live wire to switch to PT, PT to fuse to Neutral. It's just not what I'm used to seeing.

Eric.

And it was legal in the era when it was made. That's why codes change; to make things safer.

[Twist]

This may be a bit off the subject but...... Isn't Palermo, Italy where they have a huge tomb full of exposed corpses. I would love to go there to see them.

[slidincharlie (Carlo P)]

This may be a bit off the subject but...... Isn't Palermo, Italy where they have a huge tomb full of exposed corpses. I would love to go there to see them.

Yep! All people who died because of bad electrical wiring
Call me if you ever come here!

[J M Fahey]

Electrical codes

Hi Carlo.
I live in Argentina, which usually follows European Standards by default (generally DIN).
We use Blue as Hot , Brown as Cold and Green/Yellow as neutral.
Around ´95 the old European two-round-pins was forbidden (I think you still use it) to avoid what´s happening to you, easy Hot/Cold unknown swapping.
Now we use 3 angled flat pin plugs and for not-so-dangerous equipment a 2 angled flat plug.
Maybe Italy will follow soon with a similar new standard.
Ciao caro amico.

[slidincharlie (Carlo P)]

Hi JM,
in Italy most electronic equipment (radio/hifi sets, hair driers, tv/dvd sets, etc) come with a two-pin-in-a-row plug. Actually all house sockets have three pins in a row (central is for ground) and there is no way to know which one is hot and which is neutral. High current equipment like refrigerators, washing machines, etc. come with the round German-type ("schuko") plug, that needs an adapter fo fit house sockets. Clearly electrical circuits in Italy are built in a way that does not require a precise plugging direction.

[Robert M. Martinelli]

Hi Carlo,
( BTW how r u doin' ?)

Two-prong plugs are still perfectly legal ( and safe ) only when used together with appliances having a so-called "double insulation" - This indicates that the device does not need to be grounded because it is :

1 - "galvanically" insulated from mains ( usually by means of a transformer )

2 - completely enclosed in an insulated container so it's impossible for the user to intentionally or accidentally touch an energized point.

The easiest example I can think of are laptops' power supplies/battery chargers.

Cheers

Bob

[slidincharlie (Carlo P)]

(...)
The easiest example I can think of are laptops' power supplies/battery chargers.
Bob

Hi Bob,
this is fun, because most laptop's power supplies here are equipped with three-prong plugs!

[Robert M. Martinelli]

Well, only some of them, I have had the chance to own/work with ASUS, HP, Compaq, DELL and they all had two-prong plugs....my apologies if the example I used wasn't of an "universal" validity.....

Other examples I have in mind right now are cordless and mobile phones chargers/PSs, as well as ( this is closest to our area of interest ) guitar FXs PSs.

Anyway, the point I was trying to make clear is that grounding is not mandatory ( according to our current rules and regulations ) in appliances designed and built with a "double insulation" system.

Cheers

Bob