Directly connected transformerless amps

[Steve Eddy]

tryonziess, we have a policy of not allowing discussion of directly connected transformerless amps on this board due to the dangers involved in construction and operation, so I am closing this thread.

I don't understand this at all.

That thread is closed, but encouraging people whose knowledge and construction skills are virtually unknown to build tube amps with 800 volt power supplies is just fine?

Or recommending people fix their hum problems by using cheater plugs?

How are the dangers involved in the construction and operation of something like this necessarily any worse than the dangers involved in the construction of anything with an AC power supply in it by someone who doesn't quite know what they're doing?

I mean hell, a 300 watt amplifier swings 75 volts at its speaker terminals, which is more than enough to kill someone.

se

[pinkmouse]

Steve, it is our policy, as you well know. If you don't like it, you don't have to post on diyAudio. We don't force you to keep coming back.

[Peter Daniel]

If the thread in question was intended "as a learning experience" it was actually irresponsible to close it. We missed the chance to learn why "directly connected transformerless amps are dangerous in construction and operation".
.

[phase_accurate]

The answer is simple:
If the plug is inserted into the wall outlet the wrong way around or the mains wiring is wrong - the one who touches the amp will be nuked !!

This will not happen to the constructor usually but most often to his spouse, children etc ....

This should be reason enough for not attempting it.

Regards

Charles

[Steve Eddy]

Originally posted by pinkmouse
Steve, it is our policy, as you well know. If you don't like it, you don't have to post on diyAudio. We don't force you to keep coming back.

In other words, the same sentiment as that expressed by certain rednecks here in the US with their "AMERICA: LOVE IT OR LEAVE IT!" bumper stickers on their pickup trucks, yes?

Not that diyAudio hasn't the right, just want to be clear on the sentiment.

se

[pinkmouse]

Peter, as you know, it was a rule in place when we both became moderators a good few years ago. If you, or anyone else wants to discuss our policy, there is the excellent Moderating thread you opened a while back that is for just that purpose, so please post any further comments there.

[Steve Eddy]

Originally posted by phase_accurate
The answer is simple:
If the plug is inserted into the wall outlet the wrong way around or the mains wiring is wrong - the one who touches the amp will be nuked !!

This will not happen to the constructor usually but most often to his spouse, children etc ....

Well, technically they'd have to touch something more than just the amp, but what I want to know is why would the constructor somehow be the least likely to touch the amp?

This should be reason enough for not attempting it.

And I never intended to recommend anyone attempt it.

se

[anatech]

Hi Steve,
The use of directly connected power supplies without an isolation transformer is extremely dangerous. This is well accepted by just about every government in the world. We learned because of it's widespread use earlier in time.

The problem with talking about it is that young constructors normally have a very flip attitude about safety. They figure it was done before to save money, so they can do it now and save money. The same holds true of some of our less responsible members.

So, rightfully, we have a solid rule that spells out that we delete a post or close threads that deal with this practice. This is a stance that I completely agree with and support.

I'd rather that people not even consider this as an option. This is not open to discussion.

-Chris

Edit: I decided to lock this thread. Enough has been said already. Do not open another thread to continue this topic.

[Steve Eddy]

Originally posted by pinkmouse
If you, or anyone else wants to discuss our policy, there is the excellent Moderating thread you opened a while back that is for just that purpose, so please post any further comments there.

Not much point in going elsewhere to discuss policy when you've just been told by a moderator that if you question a policy you should ether accept it or just leave.

se

[anatech]

Steve,
I see this slipped by.

End of discussion! It's not about freedom to post, it's about being responsible about safety.

I will delete further posts past this one.

-Chris