Internal wire type

[GunbarrelCustom]

Does it matter if you use stranded or solid core wire in a 5e3 build? I prefer solid as it’s easier to work with and have a bunch of 18,20 and 22 gauge. I may not have enough 18 solid though.

Do I use 20 everywhere except the power delivery to the tubes and ground where 18 is used?

The writing on the wires, even the 22, exceeds my needs.

Can you use solid 18 gauge for the whole amp?


Thanks!

[bob p]

Many people prefer solid over stranded core wire because solid wire tends to stay where you put it when you bend it. At audio frequencies it doesn't matter which you decide to use.

wire gauge will depend on the amount of current being drawn through the wires. 22 ga is fine for the signal path through the preamp. anything larger would be fine as well, though large wires get hard to solder onto small terminals like those on noval sockets.

to determine what gauge of wire you need to wire the heaters you need to look at the current rating of the tubes' heaters and compare the total load to the ampacity rating of the wire being used for the heater supply. what to use would depend on how you wire the heaters. if you daisy chain all of the tubes on a single supply line then you're going to need to use heavier wire than if you sent individual wires to each tube.

[GunbarrelCustom]

Thank you! Even with a magnifying lens I struggle to read the 22, but the others say 1,000 Volts. Can that be correct? The solid 18 I have are fragments from a transformer so I’ll look for more.

[bob p]

1000V ratings on the wires would not be uncommon. Your run of the mill PVC hook up wire typically has a 600V rating.

[SoulFetish]

Does it matter if you use stranded or solid core wire in a 5e3 build? I prefer solid as it’s easier to work with and have a bunch of 18,20 and 22 gauge. I may not have enough 18 solid though.

Do I use 20 everywhere except the power delivery to the tubes and ground where 18 is used?

The writing on the wires, even the 22, exceeds my needs.

Can you use solid 18 gauge for the whole amp?

Thanks!

Yes, you could use solid 18AWG for the whole amp. But I wouldn't recommend it for a very practical reason. Solid 18AWG wire is stiff hookup wire and becomes even more stiff after soldering. This really only becomes a problem if and when you need to unsolder and resolder terminal connections and adjust wire runs. This stresses the solder terminals and boards and they can break. Which means, if your building amps, it can be a problem and probably will.
Moving on to common hookup wire types and voltage ratings - Most vintage type cloth covered hookup wire I've seen has a nominal 1000V rating. Personally, I don't really like working with it. Just a personal taste thing. The most common PVC hookup wire I usually see is type UL1007 rated for 300V, not 600V(with all do respect to Bob. But, maybe that depends on whatever local retailers stock.) There are many different industry standards for Mil-type and UL designations. But for common PVC hookup wire, you can look for type "UL1015" which has a nominal 600V/105ºC rating, and Mil-type "Mil-W-76" which has a nominal 1000V/80ºC

[bob p]

The wire insulation ratings do vary depending on what kind of device they're intended to be used with. The old cloth hook up wires had 1000V ratings because back in the tube era, high voltage was common. High voltage isn't so common today, and what's readily available in wire reflects that. For tube electronics use the type 1015 PVC wire is very common, and that's what I was referring to...

But SF is right -- most of the local stores like to stock 300V wire. That's because the wire that you'll find in the typical electrical department aisle isn't intended for tube electronics -- around here most PVC wire on the shelves is either house wire or appliance wire with a 300V rating. So you do have to be careful about where you shop, as context is important. If you go to Home Depot to buy wire in the electrical department then the chances are that it'll have a 300V insulator for 240 VAC wiring. If you buy PVC hookup wire from a tube amp parts supplier then the PVC hook up wire should have a 600V rating.

Sorry for not being specific about that.

[GunbarrelCustom]

Thanks again for the information! I wasn’t able to find solid 18 gauge in anything but 300 Volts and wondered if skin effect starts happening at that size. It looks like the kit came with 20 and 22 for most jobs including power distribution.

I’ve decided to start fresh with new tube sockets, wire and board. The pcb the kit came with was tricky because the stranded wire was the same size as the holes so if you tinned the wire it didn’t work so it looks messy. I’m also not sure it still works after the abuse I gave it lol. I’ll do el34s in a later amp.

I saw a guy that made a template of the chassis in plywood so he could mount and solder everything on a flat plane making soldering the tubes much easier than doing it inside the chassis! My giant hands hated the tight conditions.

If it works then I will make more amps as I want to mix amps and speakers in a different way than Fender did. Like a Double Deluxe in a 4x10” cab....

[bob p]

skin effect is an RF phenomenon. not relevant to audio amps.

[Pedro Vecino]

I never use solid wire except for busses. The rigidity of the wire is able to emphasize microphonics in certain designs composing a rigid assembly (especially the lines between preamp tubes and board).
Regarding the 18AWG stranded wire, once I built an amp integrally with it. It requires a lot more technique and dedication to do things right. It was a nightmare. Better only if the amp is going to be sent to outer space