Wire types, uses and sources...

[Paul-in-KC]

All,

I'm sure this question has probably been asked and answered - but I attempted several searches and was only able to find some info on preferred ground bus wire (#16 stranded pre-tinned).

So, assuming that one isn't trying to reproduce a specific vintage look with cloth shielded wire or similar - what are your choices for quality wire? I suppose to some extent the question is really more about quality insulation.

A different question is: what type (stranded/solid) and gauges do you like to (should) use in different sections of the amp?

And if you don't mind sharing sources, maybe include where you source them.

Many thanks - and sorry for what I am sure is a duplicate question (maybe a good candidate for a sticky?)

-Paul

And on a very related subject, any strong preference on solder types? I have always used whatever rosin-core solder I could find and not paid much attention to different types.

[pompeiisneaks]

I think in almost all cases wire type (stranded vs solid core) is a preference. The only case I've heard that has some merit is for speakers. Solid wire, if bent enough weakens and breaks. Stranded, doesn't. Speakers tend to be in enclosures that move a lot and can end up breaking via vibration if they're using solid core. So speakers should use stranded. I use solid core everywhere on everything personally. My reason is that I've always hated fighting stranded wire through holes, it always ends up smushing in and looking like crap, or if I pre-tin it, it doesn't want to bend nicely into place like I can do with solid core.

As for solder, I love kester 60/40 myself, and use either 0.031 or 0.050 sized solder.

~Phil

[pompeiisneaks]

Oh and source, I tend to buy my wire from a local shop, Vetco Electronics, but I've also bought it on amazon. I just get NTE PVC covered, I hear some of the guys on EL34world forums saying they love the silicone coated, I've never tried it.

~Phil

[caps8419]

Steve at Apex Jr. is a good place to get PTFE (teflon) solid, stranded and shielded as well.

[Travis_HY]

Steve at Apex Jr. is a good place to get PTFE (teflon) solid, stranded and shielded as well.

Steve at Apex Jr. is great for wire and he has a lot of the music industry specific parts as well.

There is also the larger Apex Electronics in the SF valley that has an abundance of surplus Teflon wire as well as a whole lot more. I bought a 10lbs spool of 400+ feet of shielded Teflon mil spec wire for $60 or so. More than enough for a lifetime of projects. The price was pretty remarkable.

Typically though, I prefer using Belden stranded type for everything if I can as it's easier to work with than the Teflon coated stuff and it sounds better to me in most applications. 9174 for the shielded lengths and Belden 8920 for the high voltage/high current apps. Allied and Mouser electronics carries them I believe. I don't really like the way silver stranded wire sounds on the unshielded cathodes or the plates; it has a zing that doesn't sound like a tube amp to my ears. It's amazing what a difference just the wire makes in those applications; at least to my ears.

I don't like solid core much as it can break in some applications (like the aforementioned speaker cabinet scenario) with vibration. Of course HAD used solid core. Granted, I've not done much listening to solid core wire, so I'm probably the one missing out.

And Kester 60/40 +1 here too.

[labb]

I use 20 ga. solid core, 600 volt on every thing except the speaker. Speaker I use stranded....McMaster-Carr is a good source.

[R.G.]

I'm going to stick my neck out again and speak for the technical/scientific approach.

The sound of wire types is an article of faith in the hifi tweako loonie world. To even get into this world you have to profess belief that using only your ears you can hear the difference in the stranding of a length of wire, its metallic makeup, what insulating material is used, and what solder was used in connecting it. How this is accomplished is attributed to the sensitivity of the human ear to things which cannot be measured by any instrument in any way. Oddly, true believers of these bits of dogma have been unable to demonstrate that they can actually do these bits of discrimination at a rate better than pure blind guessing in a fair test.

Instruments can and do detect things about wires that human ears cannot hear. You can, for instance, detect the distance from one end of a wire to the other end. You can even detect the distance to a discontinuity, such as another wire attached, a really sharp bend, or change in wire size at a joint. You can detect closeness to other wires if you have access to these other wires. You can even detect things like the difference in some insulation materials from others. But doing these bits of technical magic need signals that are way outside the audio band.

There. I feel better.

Solid vs stranded doesn't make a whole lot of difference at audio. The skin effect you hear bandied about does exist and does matter to RF, but is not an issue at audio, and especially not to low power audio and especially not to high impedance audio lines. Pick solid vs stranded for their other mechanical natures. Solid is stiffer per size, of course, and so it tends to stay where you put it better, but also is prone to stress cracking and nick cracking.

How you strip insulation is a big deal. Blade based strippers unavoidable nick the surface of the wire being stripped. This provides a ready-made stress concentration to create local hardening with vibration and bending, and this causes cracks that eventually break the wire. The military used to and probably still does require thermal stripping. I bought myself a Patco PT10 thermal stripper for about $30, and I don't remember where my cutter/strippers are any more. You plug the AC power line for this into the AC, and it's ready to strip in about 15 seconds. You can touch the stripping blades and not get burned. Stripping amounts to sliding the wire end into a V at the working end and turning it a half turn, then pulling it back out of the V. Wire stripped, no nicks. It's perfect on PVC and other common wire insulations. Not so good on cloth insulation. There is a high-temp variant for Teflon and other tough wire insulations.

Hifi tweakos canon aside, there's not a lot of >audio< difference in solders. Pick solders on the ease of making good, reliable joints. That generally devolves down to using qood quality 60-40 tin lead with a rosin flux core. 63-37 eutectic is a joy to work with if you've ever used it, but 60-40 is fine. Don't go messing about with lead free solders unless you have a good reason to, and saving the planet is not a particularly good reason. You might save the planet this way, but you'll do about as much saving as you would by going barefoot to minimize the amount of shoe soles created.

Lead free solder is very difficult to solder manually (I've tried) and it mostly makes for many poorer joints. This you CAN hear.

[labb]

So, R.G. are you saying that the color of the insulation makes no difference?

[Aurora]

Totally agree with RG. Cable does not have a "Sound", - and neither do metals, as in silvered or solid silver as used by HiFi freaks. There are abolutely no scientific parameters to support such a claim. Cables do have resistance, inductance, and two or more conductors as well as shielded, will have a capacitance. Singel wires will have stray capacitance vs its surroundings, which may be the reason why some people claim to hear differences between wire gauges and different insulation materials, as this will affect the capacitance. This in combination with the high impedances in tube circuits may well be audible in some situations.

[Paul-in-KC]

I'm going to stick my neck out again and speak for the technical/scientific approach...

R.G.,

A perfectly appropriate contribution to the question.

My question was trying to get at preferences for "quality wire" (really quality insulation mostly), wire types (stranded & solid) and gauges. Where people like to use what type and gauge - and why (and maybe good source).

Many Thanks!
-Paul

[R.G.]

Gotcha.

I vastly prefer PVC insulation, primarily because of the ease with which it can be thermally stripped, not nicking the wire. But then I don't give a hang about how a wire looks. Other people do care about insulation looks. That's absolutely their choice and I defend them having that aesthetic position.

I prefer stranded, again because it's easier to move, bundle, and work with. Stranded is not self supporting in the same way that solid wire is, and you can't easily make those 3D piping style layouts. Stranded will survive longer before breaking in a vibrating environment.

I do like to lace cables with waxed nylon lacing tape. My aesthetic sense prefers this, but it has very little to do with the audio quality. Lacing also makes it more difficult to work on and mod later, but - well, I tend to get things working and then not go back and do a lasers-and-ufo mod I read about on the internet.

Gauges is purely Ohm's Law stuff, with an admixture of thermodynamics. If you search for ampacity charts, you get back the recommended wire gauges to carry X current or less, both in free air and in conduit, where air flow cannot cool the wires well. Excepting heaters and speaker wires, tube amp currents are well down in the sub-1A range. The resistance of a wire either can contribute materially to a circuit's function or not. Whether it does or not depends on what else it's hooked to on each end. The plate resistance of a 12AX7 is in the range of 60K and load resistors in the 100K range. 30 gauge wire, to use an impractical extreme, is 339 milli-ohms per meter, so you'd have to string nearly 3000 meters of #30 to get up to 1% of the resistance of a 100K plate resistor. So you're probably fine with anything bigger for all but heaters and speaker wire. Use what you are comfortable handling and routing.

Heater currents are high, in the amperes range. A preamp tube is usually in the 300ma range for its heaters, and an output tube is in the 1A to maybe 3A range for some high power stuff. 6V at 3A is 2 ohms and 18W. You'd probably like your wires to dissipate much less than the heater itself, so resistances up to maybe 1% of the heater itself would be something of a reasonable threshold. So you'd like to use wire rated at 3A or over and less than 20 milliohms. From wire tables again, #18 is 20mOhm per meter. You're probably good with #18 for heaters. If you daisy chain them all instead of starring the whole string, you might need #16, #14 or so. Your house wiring uses #14 for a 15A rated wall socket, and maybe 10 meters in length. But you can use #20 for the little heaters, #18 for the big ones, especially if the runs to the big tube heaters are short.

Notice that some resistance in series with heaters may not hurt. It helps limit the dramatic surge at power on, and can be sized so it doesn't drop the voltage (and power, and resulting temperature of the filament ) significantly.

Insulations usually are printed with their voltage rating. Use 600V rated wire and you're unlikely to have issues, even with B+. If you're dealing with really high B+, you may have to get special wires. You can use 300V, which is the most general type, aside from strictly low voltage rated bell wire and sprinkler wire, for most other things. You're free to use even much higher rated insulation if you like the looks. I'm fond of the sticker I've seen with a red and yellow warning "DANGER!! 50,000,000 Ohms!".

A huge, vast, enormous aid in building amps is a bottle of liquid rosin flux. Flux core solder is very handy, but you'll be amazed at the ease of making solder joints if you dip a wooden toothpick in liquid flux and touch it to the prospective joint before heating.

[Paul-in-KC]

Gotcha.

I vastly prefer PVC insulation, primarily because of the ease with which it can be thermally stripped, not nicking the wire. But then I don't give a hang about how a wire looks. Other people do care about insulation looks. That's absolutely their choice and I defend them having that aesthetic position...

R.G.,

More great material!

I feel like I should get a certificate after reading that

-Paul

[Travis_HY]

Man, this thread is GREAT! Thanks for bring it up Paul! Wire therapy!

While I admit my lack of understanding the deep science behind wire and cable compared to the level of understanding that others here possess; as a guitar player, and as a musician, my ears can hear differences in instrument cable makes of the same length with similar specifications and manufactured with similar materials. Likewise I notice sonic differences when I have swapped wire and cable makes and types in preamplifier plates and cathodes. I can't explain it scientifically other than I notice that it clearly is different to my ears as a cork sniffin' but Fugazi lovin' guitar player.

With my very basic scientific understanding of the subject, I would think that having different spec'd wire made with different materials in both insulation and conductor being swapped for another type would in some cases influence sonic results to SOME degree.

[martin manning]

Instrument cable, sure. The capacitance per unit length of shielded cable varies from brand to brand. With single conductor wires inside the amp chassis, any audible difference is likely due to differences in routing.

[andresound]

FWIW, I have noticed in a high gain situation (Trainwreck Express), that some brands of supposedly “good” instrument cable audibly makes a noise when moved around. What would cause this?