Hoffman Amplifiers Tube Amplifier Forum
Amp Stuff => Tube Amp Building - Tweaks - Repairs => Topic started by: 12AX7 on September 17, 2022, 04:59:37 pm
-
I've been thinking about this lately after reading stories of people getting seriously zapped and even dying when their lips touched the mic with hands on a guitar. What kinds of things can I do to insure this doesn't happen besides making sure the PA and amp re grounded with a 3 prong cable into a correctly grounded mains socket? I'm using a home built amp thats never been a problem but wondering what things i can do/add to make it as safe as possible.
-
people getting seriously zapped and even dying when their lips touched the mic with hands on a guitar.
Name one person yhat died please.
-
Joe shmo.
-
Are you sure? I just saw him this morning on youtube. I don't think he's even into guitars and such. :dontknow:
-
A guy in Argentina died a few years back. It was notable because it does not happen often.
Proper chassis grounding is good practice but does not help if venue power is mis-wired or the PA system is bad. (And sometimes PA is good but some VIP demands a feed and that throws voltage on the system, happened on my watch, to my friends.)
A GFI/RCB box is good. Much better if EVERYBODY in reach has one. Of course false-tripping limits practical use.
And shattered lightbulbs.
Nylon string wood body acoustic guitar, only when lightning index is under 1,000 J/kg? Like not the Caribbean not today.
-
https://ultimateclassicrock.com/yardbirds-keith-relf-death/
-
@PPR,
You made me wonder, has anyone looked into building a GFI into an amp? Doesn't seem that hard to do...
-
@PPR,
You made me wonder, has anyone looked into building a GFI into an amp? Doesn't seem that hard to do...
Just get a GFCI extension cord or replace the power cord plug with one of these... (https://www.amazon.com/s?k=gfci+plug&crid=2C3RUWWBBM0OZ&sprefix=gfci+plug%2Caps%2C84&ref=nb_sb_noss_1)
-
Also Les Harvey, Alex’s older brother https://en.m.wikipedia.org/wiki/Leslie_Harvey
As UK electrical installations and equipment has been earthed since WWII, my guess is that the earth wire in one or more items of equipment (eg Copicat, guitar amp, PA) was lifted, to break the dreaded ground loop hum.
The best way to be safe in scenarios where things may not be ideal is to use a wireless link.
-
Sorry, typed without thinking. Just did search here--lots of takes on the idea. I believe my amps are safely grounded but I never really know about someone else's power outlet unless I"ve tested it.
-
Also Les Harvey, Alex’s older brother https://en.m.wikipedia.org/wiki/Leslie_Harvey
"Harvey died from his injuries, aged 27."
Wow, a member of the 27 club.
-
Just get a GFCI extension cord or replace the power cord plug with one of these... (https://www.amazon.com/s?k=gfci+plug&crid=2C3RUWWBBM0OZ&sprefix=gfci+plug%2Caps%2C84&ref=nb_sb_noss_1)
You just steal these from dead hair dryers.
-
You just steal these from dead hair dryers.
I thought about that too but all my hair dryers only have two prongs! Have you looked at yours lately?
-
This adapter (https://www.amazon.com/Tower-Manufacturing-30439005-Auto-Reset-15-AMP-Grounded/dp/B00UOU6OVU/) is probably the easiest way to add GFCI protection to any plug-in device.
-
In a similar vein are GFI plugs with triplex outlets, because you always have multiple gizmos (guitar, pedals) and you must protect ALL of them.
Another path is plug-only with your own outlet scheme:
https://www.homedepot.com/p/4-67-in-15-Amp-Manual-Reset-3-Prong-Portable-GFCI-Replacement-Plug-Assembly-EG20PMS0201-5P/321180075
https://www.amazon.com/Replacement-Assembly-Interrupter-Protection-Conditioner/dp/B077FV6RQT
-
Here's everything you need to know about GFCI in an easy to understand format. Everyone on this forum can understand the theory of operation.
-
...all my hair dryers only have two prongs!
OK. I know what I was thinking. The electric pressure-washer has a 3-pin GFI end on it.
https://www.amazon.com/Replacement-Circuit-Breaker-Waterproof-Auto-reset/dp/B07DWNCQG2
Agree you don't have dead pressure-washers laying around. At $17 it may be cheaper and easier than an in-wall GFI plus box and cord.