Getting zapped by SM-58 mic

[Mincer]

Easy fix - it was just the kettle lead that came with the amp, presumably the insulation is damaged somewhere all working fine with a new lead

Happy that shock wasn't more severe (those really suck), and that you figured it out.

[Erlend_G]

Cool!

I once measured +45V between the mic capsule and my bass guitars' strings. The live? and ground wires were crossed between the bass/PA amplifiers :/ ..

[Ewizard]

When I wire my stages for bands I do everything I can to make it so ALL the power for the band and any connected mixer or stage box is coming from a single circuit.

I have not had a band yet that can pull more than 1 circuit worth of power, so there is little need to run power for a band off of multiple circuits. Most guitar and bass amps only pull a couple hundred watts, a full 15amp circuit has 1800 watts that you can use. So with a stage box that only pulls another 200 watts, you can easily power 6-9 x 200 watt to 300 watt devices. Since 90% of bands don't have that many amplifiers running at one time, you can generally keep the circuit count down.

With the stage box and the band all powered of one circuit, it is very difficult to have ground loops and voltage differentials between devices.

The biggest deal ever is to ensure that your amplifier plug is good and wired properly.

[El Dunco]

My 58Beta did that to me with “The Twin.” Not wiany other amp and only in one place. Dodgy grounding.

Not cool! Might have burned my lips off.

[beaubrummels]

When the source is elusive, I just put the windscreen on it, don't touch it and add a few db somewhere between 8k-12k on the board.

[uOpt]

I could go preaching again that the usual grounded strings to abuse the guitarist as a shield is life-threatening nonsense

[El Dunco]

I could go preaching again that the usual grounded strings to abuse the guitarist as a shield is life-threatening nonsense

I’ve wondered about that. Makes me paranoid I’m one faulty-grounded building away from becoming the ground but with wireless, the most that can go through me is 3 volts.

[uOpt]

I’ve wondered about that. Makes me paranoid I’m one faulty-grounded building away from becoming the ground but with wireless, the most that can go through me is 3 volts.

Yeah, wireless helps.

I'm not just concerned about buildings without 3-prog outlet, I am concerned about broken amps that have a problem telling mass/ground and one of the 115V hot wires apart after a defect in a cable or the chassis.

[El Dunco]

Yeah, wireless helps.

I'm not just concerned about buildings without 3-prog outlet, I am concerned about broken amps that have a problem tell mass/ground and one of the 115V hot wires apart after a defect in a cable or the chassis.

Oh boy. I swear I’ve heard a horror story or two of that nature.

I’ve forgotten so much of my small electrics course. Let me get this right. The guitar wiring “ground” is always soldered the bridge. Does that mean it’s going (or could go) through you to ground? That would be the past of least resistance and if I know electricity, it really wants to go to ground.

[uOpt]

Oh boy. I swear I’ve heard a horror story or two of that nature.

I’ve forgotten so much of my small electrics course. Let me get this right. The guitar wiring “ground” is always soldered the bridge. Does that mean it’s going (or could go) through you to ground? That would be the past of least resistance and if I know electricity, it really wants to go to ground.

No, it doesn't go through you. It just abuses your belly as a shield for the otherwise unshielded back of the electronics cavity. That shield (you) works even if you have rubber boots on.

In the rubber boots you wouldn't be outright killed by the grounded strings when the amp screws up. It would wait until you touch real ground such as a microphone.

[El Dunco]

No, it doesn't go through you. It just abuses your belly as a shield for the otherwise unshielded back of the electronics cavity. That shield (you) works even if you have rubber boots on.

In the rubber boots you would be outright killed by the grounded strings when the amp screws up. It would wait until you touch real ground such as a microphone.

Bloody hell!

[uOpt]

Sorry had a typo. In the rubber boot you wouldn't be outright zapped (until you touch the mic).

The nice thing about these zaps is that you muscles in general and left hand in particular cramp up, and that usually means around the guitar neck

[El Dunco]

Sorry had a typo. In the rubber boot you wouldn't be outright zapped (until you touch the mic).

The nice thing about these zaps is that you muscles in general and left hand in particular cramp up, and that usually means around the guitar neck

You might have just come up with a way to get away with murder by amp malfunction.

[spleenharvester]

Spoke too soon, it's happening again. At this point I have swapped all power cables and adaptors out for different ones and tested the outlets, so I'm really flummoxed by this.

Only thing I can think of is that possibly it's happening once the tubes in the amp or the mic preamp are warming up, which could be giving the false impression initially that whatever I've done has fixed the problem. Could faulty tubes do this?

EDIT - I think this is actually happening mic preamp-side, if I keep the amp on and unplug the power from the preamp the shocking stops, but if I turn the amp off and leave the preamp on the shocking continues. It also takes about 30 seconds for the shocking to start after the MIC500USB is powered on, regardless of how long the amp has been turned on.

[El Dunco]

Spoke too soon, it's happening again. At this point I have swapped all power cables and adaptors out for different ones and tested the outlets, so I'm really flummoxed by this.

Only thing I can think of is that possibly it's happening once the tubes in the amp or the mic preamp are warming up, which could be giving the false impression initially that whatever I've done has fixed the problem. Could faulty tubes do this?

EDIT - I think this is actually happening mic preamp-side, if I keep the amp on and unplug the power from the preamp the shocking stops, but if I turn the amp off and leave the preamp on the shocking continues. It also takes about 30 seconds for the shocking to start after the MIC500USB is powered on, regardless of how long the amp has been turned on.

Leave no stone unturned. Get a multimeter and please, be careful.