Shock from amp...after being unplugged

ICBM

Fenderish said:

in good old amps, the caps are after the mains switch, so if you put the mains switch on off, you can never be schocked by unplugging the cable. on modern amps, such things as a mains supply board with the caps is still on the mains after having switched the amp off, Don't like that...

In quite a few, the spike filter is integrated into the IEC socket.

Fenderish

still not a good idea, I had a computer with the same kind of filter and got shocked regularly by accident, I hate this

TeleMaster

Sorry. Can I just check as I’m worried now. What shouldn’t I touch and when? I’ve got a heart condition so I don’t want to die.

ICBM

TeleMaster said:

Sorry. Can I just check as I’m worried now. What shouldn’t I touch and when? I’ve got a heart condition so I don’t want to die.

The pins in the IEC mains socket or the pins on the mains plug at the other end of the cable, if the amp end is still attached to the amp.

TeleMaster

Didn’t know that. You mean the actual metal pins that go into the wall? Feel like I’ve done that before but never had a shock. After I’ve turned off the amp and then taken the plug out of the extension cable or whatever.

prlgmnr

Alright; own up, Fretboarders.....how many people have gone and given themselves a shock on purpose using this method just to find out if it's really true?

ICBM

TeleMaster said:

Didn’t know that. You mean the actual metal pins that go into the wall? Feel like I’ve done that before but never had a shock. After I’ve turned off the amp and then taken the plug out of the extension cable or whatever.

There are a lot of amps that don’t do it, because they either don’t have line filters at all or they’re on the other side of the power switch.

p90fool

digitalscream said:

ecc83 said:

The mains RF filter cap is fitted to most pieces of kit but the designers don't think peeps are going to grab the plug pins!

An understandable assumption (ish), but it kind of defeats the point of the safety aspect of male/female plugs

Also, it's fine if the charge dissipates quickly, but for it to still be there 10 seconds later isn't good design IMO. Sure, I can unplug from the device first, but the bassist in our band picked the amp up (remember, it's only a small box) and accidentally got fingers near the mains socket and got the same shock when it shifted in the hand.

The only real preventative, I suppose, is to stop using the power switch on the amp and use the mains socket switch instead so the caps discharge instantly.

Or discharge it on the drummer's tongue before letting the bassist carry your amp.

jpfamps

RiftAmps said:

ICBM said:

 It is a rather remarkable oversight in the regulations though.

@jpfamps do you know if the new regs are addressing this?

I've not looked at that part of the regs as I've not been involved with approvals of a mains powered product under the new regs.

Other than the cap has to be Class-X, I'm not sure what other requirements will be.

Getting products through EMC approvals, especially class D amps, is now getting be a real pain, especially if you are aiming to trade in mulitple territories.

I expect as Dave says adding a bleeder resistor to the mains side may not be a cure either as you would not know if the resistor had gone open circuit and assume it was "safe".

Hootsmon

ICBM said:

TeleMaster said:

Sorry. Can I just check as I’m worried now. What shouldn’t I touch and when? I’ve got a heart condition so I don’t want to die.

The pins in the IEC mains socket or the pins on the mains plug at the other end of the cable, if the amp end is still attached to the amp.

eh?

Hootsmon

ah. think I've got ya......damn didn't know that

So don't touch this after you have unplugged from the wall for a while?

ICBM

hootsmon said:

ah. think I've got ya......damn didn't know that

So don't touch this after you have unplugged from the wall for a while?

Yes - don't touch those pins unless you've already unplugged the amp end from the amp.

Length of time doesn't really matter, the caps will hold the charge almost indefinitely if they're in good condition - certainly hours, maybe longer.

The majority of amps aren't like this, but the first time you get one that is it gives you a nasty surprise!

Kittyfrisk

hootsmon said:

ICBM said:

TeleMaster said:

Sorry. Can I just check as I’m worried now. What shouldn’t I touch and when? I’ve got a heart condition so I don’t want to die.

The pins in the IEC mains socket or the pins on the mains plug at the other end of the cable, if the amp end is still attached to the amp.

eh?

The mains (power) cable is not connected to the wall but is still attached (plugged in) to the amp. 
So it is possible to pick up the mains end (the one that really fucking hurts when you stand on it barefoot, even when no electricity is involved) & bridge the pins with your hand, hence making the earth that the ouchy stuff likes.

Kittyfrisk

Apologies for the delayed post, saying what was already stated earlier, my current browser issues are legion & hilarious   

TeleMaster

Well this is unsettling lol

Kittyfrisk

TeleMaster said:

Well this is unsettling lol

You better believe it 
Chrome on Mac has been 'improved' & now is randomly not displaying images & other such such fun behaviours on this site   
I couldn't see Hootsmon's pic of the mains plug & helpfully composed my reply, which was exactly what ICBM had said...

Training myself to use another browser, so fingers crossed all future cock-up's will be entirely my own   
Cheers.

ICBM

Kittyfrisk said:

Training myself to use another browser

Safari? Works perfectly well for me...

crunchman

ICBM said:

Kittyfrisk said:

Training myself to use another browser

Safari? Works perfectly well for me...

I've not used the latest version, but the old version was horrible.  I used Firefox until I got rid of my Mac.  I also use Firefox on PCs.

Kittyfrisk

Yes Safari is the new FB browser of choice. It has always been fast & stable since its release, but its interface is a bit drab & 'meh'.
Chrome took some getting used to, but after a few iterations, it got to be OK.
Firefox used to be good, but I started getting loads of runaway processes, so jacked it in.

I like the adblockers, Ghostery & other apps integration for Chrome, as I prefer to control what I see & really hate trackers etc..

Still, they are all just tools & you can't fix everything with a hammer  

TeleMaster

Kittyfrisk said:

TeleMaster said:

Well this is unsettling lol

You better believe it 
Chrome on Mac has been 'improved' & now is randomly not displaying images & other such such fun behaviours on this site   
I couldn't see Hootsmon's pic of the mains plug & helpfully composed my reply, which was exactly what ICBM had said...

Training myself to use another browser, so fingers crossed all future cock-up's will be entirely my own   
Cheers.

I’m more talking about the bloody electric shock from an amp. But I’m sorry to hear about your browser woes lol.