Grounding cap on a three prong AC cord?

[Randall]

I am doing a recap on a CBS red plug Champ. It has the so called death cap on the hot side to chassis. While I don't think it is dangerous since it's a polarized plug and the ground wire is soldered to chassis, I'm vacillating on whether to leave it or remove it, and am looking for opinions. Thanks

[Leo_Gnardo]

If someone was ever to use a 3-to-2 wire AC adapter, or snip off the ground pin on the AC plug, that makes the Champ a sure fire shock hazard. I'd remove the cap.

Having replaced hundreds of 2 wire AC cables with grounded 3 wire cable sets, I've wondered whether or not it's a good idea to remove the death cap. In recent years I've made the decision to remove it in all cases. I can't see that it's a good thing to have. It either does nothing useful, or provides a shock hazard if the amp isn't properly grounded thru its AC cable. I'd be interested in hearing any opinions/arguments that the death cap should be left in place, and why.

[potatofarmer]

Enzo and RG agree that it should be clipped out in this thread: http://music-electronics-forum.com/t32489/

[Leo_Gnardo]

Enzo and RG agree that it should be clipped out in this thread:

One could hardly ask for higher authority. If Juan and Gingertube pitch in an agreement I'll be 200% convinced!

[GainFreak]

The death cup should be removed but nowadays most amps have an X2 rated cap in parallel with the PT primary (after the power switch and maybe together with a MOV and/or NTC) which does the same job but this ways it can't short the hot side to the chassis.

[Jazz P Bass]

Although the 'death cap' is rated at 600Volts, it is NOT the correct type of cap to be used in the application.
(a lot has been learned since the 60's & 70's)

If it fails 'short' in a 2 wire adapter situation there is distinct possibility of a shock hazard.

Clip it out.

[DrGonz78]

While the cap has not yet shorted out altogether it is old and could be leaking some AC voltage to ground. I have had tiny shocks from just 3-5vac trickling through to ground while servicing an amp. To me leaving an old death cap (possibly leaky and capable to short) in an amp is just an avoidable accident waiting to happen.

[The Dude]

If someone was ever to use a 3-to-2 wire AC adapter, or snip off the ground pin on the AC plug, that makes the Champ a sure fire shock hazard. I'd remove the cap......

Exactly. The cap must go. The amp simply isn't safe with it there. It's also not necessary if you have a grounded plug. It serves no purpose other than a potential shock hazard. Also, how many times have we seen the ground connection not even hooked up in some shoddy bar?

[Randall]

Then off it comes!

[The Dude]

Re; shoddy bars: The phrase "My brother's wife's friend used to be an electrician" comes to mind.

[Leo_Gnardo]

Re; shoddy bars: The phrase "My brother's wife's friend used to be an electrician" comes to mind.

No, electrician's assistant. And they paid him with booze on Saturday night to wire up the place Sunday morning.

Definition of "ground:" what I'm laying on after I get a good shock.

"Ya don't need no stinkin' fuses!"

"Breakers" is where ya go surfin'.

"Code": that's for spies to figure out.

[The Dude]

Another that always makes me laugh: It's an old 2 wire system. They put in a shiny new metal box with grounded outlets, use the existing 2 wire romex, and run a little ground wire from outlet to box which goes to nothing.

[olddawg]

Another that always makes me laugh: It's an old 2 wire system. They put in a shiny new metal box with grounded outlets, use the existing 2 wire romex, and run a little ground wire from outlet to box which goes to nothing.

Honestly I've been shocked so many times with "safe" gear on so called "grounded" stage AC mains that I almost always use a wireless and have a digital AC voltmeter built into my pedal board. No ground, reversed mains, low voltage, artifacts... incredibly common. I haven't quite got to the "power conditioner" point yet. I did watch a band smoke their gear on a generator a while back.

[g1]

In vintage stuff, remove when doing 3 prong conversion.
As far as why they are needed with 3 prong, some modern amps use them (proper x or y types). 5150 for example. Some examples on polarity switches, some not. I wouldn't go removing those while some may call them 'death caps'.

[Chuck H]

Re; shoddy bars: The phrase "My brother's wife's friend used to be an electrician" comes to mind.

Oh hell yes that happens. Just a hum through the monitors while I stood momentarily frozen to the mic via my lips. Then My knees hit the stage and my guitar was just open strings blaring. I earned the moniker "Sizzlin' Chuck" that night. I never mentioned to anyone afterward that it wasn't for my playing.