Vintage Super Lead Death Cap and Polarity Switch

[cap217]

I have read the old threads and searched the internet on death cap removal but Im still unclear. I have a 73 handwired super lead that had a 3 prong installed but they kept the death cap and the polarity switch hooked up. Its confusing because some diagrams have the polarity switch still working without a death cap and others say the polarity should not be functioning at all.

I read that Lane Sparber said this (which is the most to the point Ive found):

"There should be a cap going from the center pole(s) of the polarity switch to ground. Sometimes it's on the end of the PC board. Follow the wire. Remove the cap (it's usually a .05uf capacitor). Done. With nothing connected to the center pole, the switch no longer does anything.
Install the 3 prong cable with the black wire going to the fuse and the white wire to where the old wire was on the polarity switch from the 2 prong cable. Ground the green wire somewhere near the power transformer."

My amp is a little different. It has a red wire from the polarity switch to the death cap to ground. But now that I am looking closer, I dont know whats going on.

New 3 prong is:
green to ground
black to fuse
blue to power switch

The polarity switch has wires on it but I dont know where they are going or if its functioning. So the amp might be ok as is.

 

[Jon Snell]

The sole purpose of the "death cap" was to allow any mains interference to be stopped from entering the amplifier if and only if, there is no earth or ground wire in the mains lead.
On 110volts it can give a tingle or a slight shock, if it is not faulty but on 240 mains it is definately seriously dangerous and must not be used.
As you have a three core mains cable, just remove it. It looks like the wiring is OK as it is, as the ground goes to chassis and the mains to the switch, in your photo.

If however, the cap fails in your amplifier, it will take out any earth leakage trip if you have one, otherwise there may be smoking parts within!

Edit; it is probably left in their hoping it looks "stock" whatever that is over the pond. Certainly not stock here where they are made.

 

[PelliX]

Indeed, chop out the death cap, you don't need/want it. Use the amp earthed at all times (applies to any earthed-by-design electrical appliance, of course). As for the polarity switch, I'd leave it as is; if it's working - excellent, you can use it as intended. If it's not working, no great loss, you can still flip the plug...

Jon, as far as I'm aware the death cap *is* indeed a US thing entirely.

 

[cap217]

I’m confused here. The polarity switch and power switch are wired together.

I don’t know what I should do here.

 

[cap217]

Also, different amp. This is a 72 I have and checked. It looks like the polarity switch was taken out of the circuit just fine but the white and black wires are reversed. Should I switch them?

 

[cap217]

Here is a diagram of each. On the 73 polarity is still in.

 

[PelliX]

I’m confused here. The polarity switch and power switch are wired together.

I don’t know what I should do here.

I believe Jon's and my recommendations were fairly to the point; remove the cap and leave the new lead and polarity switch as they are. If you're in the US and have the corresponding polarized plug, then you could consider bypassing the polarity switch. Many parts of the world do not use polarized plugs and therefore the polarity is a 50/50 gamble each time you plug a device in (unless you label the plug *and* confirm the wiring in the socket).