Advice please: "Safety Cap" wiring / wireless system

[asmith]

It feels good posting here again. Like sitting in an comfortable chair I used to know.

Background
I finally gave my Les Paul copy the upgrade it has awaited for a decade: new pickups (new 10 years ago), four push-push pots, and a re-imagining of Borsanova's Twenty-Dual scheme. When the below questions are answered and the build is finished, I'll start a new thread with photos, the circuit lay-out, and so on. The questions below concern electrical safety; I have a 100-watt tube head that is older than I am that I would like to play this guitar through, but I want to remain alive.

Question 1 - A "blocking" capacitor
ChrisK's thread here expanded John Atchley's advice to add a "blocking" capacitor to guitar wiring. If you haven't read that thread, please do so before reading further. Adding a "blocking" capacitor is what I want to do. Here's what I have on my wiring scheme at the moment:



(I wish the wiring between the switches and the junction box was neater, but it's not, and I have to accept that.)

The green-marked "Ground out" lug on the junction-box goes to the jack's ground lug.
The red-marked "Operator Touchable Components" connects all the shielding and grounding in the guitar: the bridge, the pickup grounds, the component cavities, and the switch components themselves.

As per ChrisK's advice, I am to find a 0.33 uF 600 VDC cap to connect the two lugs. Trouble is: I'm not a qualified electrical engineer and I have no idea what capacitor I'm looking for.

E.g., is this the kind of thing I need? (Link is to German Amazon, because I live in Europe.)

Question 2 - wireless systems and pedals
I also plan on buying a wireless system, as per ChrisK's further advice. Does anyone have any recommendations for one?
Or, can e.g. any pedal that is electrically buffered (e.g. a tuner pedal) potentially act as further protection against disaster?

[thetragichero]

i am of the opinion that no amp should be played without a three prong cord (or iec jack so you can just take an iec cable from an old computer or monitor and use it) and death cap removed

that being said, find a 600v 330nf (0.33uf) capacitor that will fit. doesn't need to be any specific brand or highly coveted for its "mystical tone" properties (hogwash but i keep finding sprague black beauty/vitamin Q caps at the electronics surplus store and i'll damn sure throw em on reverb for those with more money than sense). axial, radial, doesn't really matter. whatever will fit. i wouldn't even worry too much about value if 220nf or 470nf are easier to source

[asmith]

Jul 30, 2021 19:32:59 GMT -5 thetragichero said:

i am of the opinion that no amp should be played without a three prong cord (or iec jack so you can just take an iec cable from an old computer or monitor and use it) and death cap removed

Right on, thanks! Was planning to take my amp to a tech and get them to check/replace the filter caps at the front of my amp-head's pre-amps. This is a sensible thing to do, right?

Jul 30, 2021 19:32:59 GMT -5 thetragichero said:

axial, radial, doesn't really matter. whatever will fit. i wouldn't even worry too much about value if 220nf or 470nf are easier to source

This is very clarifying. Thank you.

[thetragichero]

i look at replacing filter caps like i do changing the oil in a car: if you wait until it's a problem, it's a PROBLEM. this goes doubly if you gig with the amp: would you like to take care of the problem when you have time or figure out what to do in the middle of a gig?
if it's more than 20-30 years old those electro caps are on their way out (electrolyte dries out, may become leaky, etc). hundred bucks or so parts and labor (i'd expect) to change the filter caps, bias supply caps, ideally any electrolytic bypass caps still probably saves bench fees troubleshooting later on

it's possible i'm just too cautious though... i used to bring a small tool box with spare tubes, soldering iron, pots, etc