Safety Questions

[Stagefright13]

The most important safety gear you can have is knowledge. Don't mess with anything unless you know how it works. You don't have to FULLY understand the audio aspect of it. But understanding B+ or the AC voltage in tube projects is important. In the US the B+ is double the wall socket at your studio. I learned these things here. Especially about all the Power supply Transformers hook up threads. Most new people ask about that. And have no idea how to properly hook their AC mains to the power transformer.

Tube gear such as the G9 step the voltage up from US 110/120 to 300?? or more. I usually measure 245 to 275ish.  But the input voltage from the transformer is often 320 or better. For tube stuff. Ever wonder why your grand pop flew across the room trying to open his TV??? Safety is a very good thread here with tube projects.

And if you don't have a DMM monitoring the high voltage caps at all times or know how to hook the DMM there you should step away. OR ask LOTS of questions before you start.

Just because Gyraf's G9 sounds ridiculously good doesn't mean you can't build it without some safety. Before you even start you MUST know where the high voltage line is and how to measure it.

I think many people won't reply here on safety cause they may become liable in some wacky court of law. So I am making a disclaimer that I never suggested anyone build a high voltage tube project. Because I have NO control of how it was done or the safety of individuals that participate in this.

John

John

 

[Mike Cleaver]

You often can find variacs on Ebay for much less than new.
Another good source, radio stations that have them in the shop but don't use them any more because most have no tube gear.
You could check around at local radio stations and you might even get one for free.
Some will be old basic ones without meters but you can use your multimeter to monitor the voltage on the output.

 

[sonolink]

@Mike
Thanks for the radio stations tips. That's quite a good idea actually  8)

@Stagefright13
John, I'm not sure I understand what you mean. What's wrong? People are talking about safety here aren't they?

 

[sahib]

Yes, keep your left hand behind during testing is a universal rule particularly for high voltage inspection.

I knew a person (who is probably long retired) who worked for the electricity board in Turkey and was electrocuted by 18KV. I am not talking about a TV flyback here, it is a HV transmission line. On the right hand side of his body starting from his arm pit down to his legs, his body exploded in few places where the current exited into the metal pylon. He survived.