Edge Deluxe: RFI Cap

This doesn't strike me as an ideal introductory teaching tool (I think it might be a technical explanation attached to a product), but for the quick search I did it seems to explain class X capacitors on the mains AC reasonably well.
http://www.minuszerodegrees.net/line_supression/capakor_general_technical_information.pdf

And an overview of the rest of the Edge Deluxe stuff here, though you've probably already found this.
https://robrobinette.com/5e3_Modifications.htm#Edge_Deluxe_Mods
Cheers

 

It's in the first link, above. class X means, if this document has it right, across the hot and neutral on the primary side of the power transformer, parallel to the load (the rest of the amp), and because it is across those two leads and not connected to anything else (nothing on the secondary side of the circuit, nothing attached to the chassis), it can't fail and present a shock hazard. That's how they define class x in the document. It's not very long, check it out.

 

I could never confirm the placement of the Class X cap but like Snfoilhat said it's most likely placed between the power input's hot and neutral.

I just noticed Fender used "flying" heater leads on the Edge. How did I miss that?

 

I left it out on my Edge mod and the two additional fuses. I think the big game changer is Mercury transformers and Celestion Blue. I built two identical 5E3 except one had a classic tone transformer the other the Mercury’s you could tell deference MM just sounded that little bit better. The cost of the MM transformers is pretty high then throw in a Celestion Blue. I didn’t have the Transformers and Blue I would not have built. Myself I like the sound of the Amp It’s not night a ground-breaking difference than a stock 5E3 just something a little nicer.

 

Does this help? Is it C14, the cap on the board closest to the P/T?

 

^Yes, JuneauMike, that is how the Edge is wired and yes C14 is the RFI cap, a 275V .1uF Class X capacitor connected across the mains hot and neutral wires. Thanks for the schematic Uncle Daddy, I hadn't seen that before.

 

That schematic says, "57 Deluxe / Fender 57". It is very similar to the Edge but the phase inverter-to-power tubes coupling caps are shown as 5E3 normal .1uF where an Edge owner has reported the caps as .022uF. It also shows rectifier protection diodes and a surge control thermistor on the mains neutral line.

 

https://www.allaboutcircuits.com/technical-articles/safety-capacitor-class-x-and-class-y-capacitors/



X means line to line

Y means line to ground

 

Hears a pretty simple definition https://www.justradios.com/safetytips.html Is an RFI cap a necessity all of a sudden? How many guitar Amps have them? Is it some new safety requirement?

 

I added one to my 5e3. It acts as an anti pop cap on the main switch. If your new $2000 Custom Deluxe went bang every time it got switched off, you'd be a bit concerned.

 

I agree Mike, the Edge handwired 5E3 does look like a very nicely made amp with some nice modernization upgrades.

 

Now I'm thinking on my upcoming Tweedle-Dee mod adding the RFI cap. then I read this on Robs sight "Fender added two additional 250V 4A fuses to the circuit board for the 6.3V and 5V heater circuits for power transformer protection." now that sounds like good idea, So would the fusses be inline for one leg of each heater wire? I can't find any good information on there placement.

 

One fuse in the heater circuit is good enough if there's no real 6.3v center tap.

https://robrobinette.com/Generic_Tube_Amp_Mods.htm#Protection_Mods

 

Thanks Rob looks like 4 fuses found a fuse block Mouser. On the Safety capacitor (RFI type X) what voltage rating do you Suggest?

https://www.mouser.com/ProductDetai...ha2pyFadujXrjG/%2bgPtv5tD6qMqQdqv0YBACIgHGjM=