Internal Wire Gauge?

2.0 welding cable should be fine. Make sure it's grounded well.
Pure silver multi strand, I figure about 25k for cable, 500.00 valve amp..
LOL

Reality,

20 -16 unless it's a PS. The small wire is a must for dynamics.. I tried a few times.. I like solid core copper and silver in certain places. I like cloth wire covers, cotton, silk, some had asbestos in the blend..

So you gonna build, or REbuild, or just want to know?

It's not big wire, BUT DIY usually go to big.. Great solder, short paths, twist the right wires for noise... Quiet as a mouse with good valves and quiet transformers..

Regards

Agreed with @oldhvymec on the use of solid core. 

Stranded blurs the sound in my experience.  I had a preamp and took Duelund's tinned-copper in oiled cotton, compared one input with the original 16ga wire to another with a single strand of the tinned-copper wire in an oversized teflon tube.  The single strand was superior in every way.  

That said, I personally prefer solid core silver.  I use VH Audio's 99.999% pure silver in cotton for the signal path of all my electronics.  28ga, so I'm even smaller than 'ol mec.  https://www.vhaudio.com/wire.html

When I'm going out to the speakers from the amplifier boards, I use 14ga solid silver from tempo electric (http://www.tempoelectric.com/cables_speaker-cables.htm).  You've got real current at that point, so larger gauge wire is better.

Based upon advice from either John Curl, of John Risch (forget which) I ended up using 18 or 20g solid core (SC) for the ground runs/busbar in a vintage pilot 240 (the 26g SC that I first tried was noisy).

I used 26g SC (47 Labs OTA) for the signal paths and it worked well.

I left the original stranded power wire intact, so don't have an opinion on that.

This said, there was guy advocating Huge gauge stranded wire off the OT's in DH/SET amps (maybe 8g-10g), so my guess is that it depends upon the specific amp (PP with gobs of feedback VS DH/SET with none).

So...

You have ground/power/signal paths in the mix to figure out what seems best (for each) for your specific amp.

DeKay

Addendum:

One of the John's is a Jon (sorry forget which, but both have given me sage advice in forums over the years - which was much appreciated).

DeKay

18 gauge for the power wiring to and from the mains xfmr and 20 gauge for the signal wiring to and from the output transformer. The wiring should be UL1015 listed (600 volts and 13 amps for #20 and 18 amps for #18 at 40 degrees C)

You should take these questions over to DIYaudio where you'll run into a lot of builders. :)

Best,

Erik

2.0 welding cable should be fine. Make sure it's grounded well.
Pure silver multi strand, I figure about 25k for cable, 500.00 valve amp..
LOL

Beat me to it! :-)

The wiring should be UL1015 listed

That's really specific and unnecessary. UL1015 is 600V  PVC shielded appliance wiring material. It's in an enclosure, there is often no need for shielding at all, and it would be detrimental to the build in many locations.  Where shielding is required, there are any number of UL style wires that would be suitable depending on where used, how supported, etc.

I'm not saying you should not use premium wiring, however, for price consideration:

If/when you take the bottoms off vintage equipment or backs off vintage speakers, you will be amazed how small and common the wires were/are.

Keep in mind, this is what made those vintage audio companies famous.

@greg7 - I have designed and tested many DIY cables and the following are the wires I have found to excel when used for the signal/live wires in all my cables

One of the things that can hinder the performance of wire is the insulation

• insulation acts like the dielectric in a capacitor and causes noise to be generated in the signal
• The Dielectric Constant (Dk) of the insulation is a guide to the "level of impact"
• the Higher the number the more noise is created
• Dk of a vacuum is 1.0 and of Air is around 1.1

Neotech UP-OCC copper with Teflon insulation (Dk=2.2) is an extremely good wire
VH Audio UP-OCC copper with AirLok insulation (Dk=1.45), is also extremely good, but for some reason I preferred the Neotech, while others preferred VH Audio
VH Audio also has a UP-OCC solid silver wire with AirLok insulation (Dk=1.45) that is about as good as you can get

Solid wire is better than a stranded wire

I avoid the use of silver or gold plated wire for the signal wires - plating seems to impacts sound quality

Mundorf has a Silver with 1% gold wire that lots of people like

• I preferred the Neotech and VH Audio wires.
• They were more dynamic and provided better imaging and clarity

Duelund Tinned Copper in Cotton/oil insulation (DK is around 1.3-1.4) is often referenced on the forum,

• and some people prefer it to other wires,
• but I found is was not as dynamic as the other wires above, but it is a good wire

I hasten to add when you get into this level of wire quality - ALL the wires I have mentioned above provide exceptional sound quality - it could be a matter of personal preference

As a previous posts above mentioned, the best insulation solution is to use Bare wire in a slightly larger Teflon tube (Dk is very close to 1.1) ,

• I now use this approach on all my cables
• it is about as good as you can achieve on planet earth :-)

WRT the neutral wires in my cables - I use a stranded silver plated copper Mil-Spec in Teflon wire

• I have tried several better wires for this duty,
• but strangely, I am yet to find a wire that outperforms the Mil-spec for the Neutral

So does using premium wire really make a difference?

• I believe that depends on YOUR ears and the rest of your system components
• I can hear the difference in my cables between all of the wires mentioned above regardless of whether they are Interconnect, speaker of power cables, so I would have to say YES!

As for which gauge - that depends on the power requirements of the circuit, but it seems from the posts above 18 gauge will suffice and bearing in mind you are dealing with high voltage inside a tube amp, then the current in play would probably be quite low. But I would recommend you check this out thoroughly before proceeding

Regards - Steve

@williewonka Great read, thanks for the detailed post. 

And glad to see we're hearing similarly.  Always good to find another person who hears what you do so that you can pay more attention to their comments and recommendations.

And yet $100,000 CD players (and amps) are built on PCBs using generic copper, typically FR-4 substrates, though I have seen the odd PTFE, though their is little justification for it.

PTFE (Teflon like) insulated wire does not need to cost an arm and a leg, it is common for industrial and military uses and costs a fraction of "audio" wire..

Then again, using PTFE for hookup wire is pretty silly unless you are running twisted pairs (or similar).  Individual wire runs don't benefit for a low dielectric constant. You need two conductors to have a capacitor, so if one wire is 10mm away from another wire, and you have 0.1mm Teflon insulation, the air is still by far the dominant dielectric.

If you are selling things and want to impress people who don't know any better, sure use expensive wire that will make no difference. However, if you are building your own stuff, every dollar you don't waste on wire can be used in places where it will actually make a difference.

Different wire sounds different in my system and with my ears... even when it's connecting to generic circuit boards.  Cost is low compared to other things in this hobby because you're dealing in inches, not feet.  Easy to try.  YMMV.

@elliottbnewcombjr

"If/when you take the bottoms off vintage equipment or backs off vintage speakers, you will be amazed how small and common the wires were/are."


@audio2design,

"And yet $100,000 CD players (and amps) are built on PCBs using generic copper, typically FR-4 substrates, though I have seen the odd PTFE, though their is little justification for it."



Nor should we forget cartridge wires or internal loudspeaker wiring (coil and crossover). These are chosen to be fine by design, and not by cost.

Electricity seems to be a fickle beast and simply loves to flow. It doesn't seem to care too much about which route it has to take as long as there is a route. 

I remember reading about a loudspeaker designer who claimed he once ran his $10k+ top of the line speakers through a single strand of cable to see if they would sound ok.

Apparently they did.

Audiophiles on the other hand don't seem to satisfied until they've got the audio equivalent of running a garden hose through the Mersey Tunnel.

Suitable for Framing ...

"  Electricity seems to be a fickle beast and simply loves to flow. It doesn't seem to care too much about which route it has to take as long as there is a route. "

I don't know about other folks, but I try to avoid accidentally buying 300V wiring for tube amp builds. The wire rating I cited above is used by transformer manufacturers in their mains and output transformers. UL 1015 is not shielded wire; it is a PVC jacketed hookup wire with a rating of 600V and is specifically designed to work in appliances, including tube amplifiers.

And don't forget to check the voltage ratings of the resistors. Some of those boutique brands (including Vishay RN60) are rated for 200 volts, and you can easily drop that voltage in tube amps.

Yes bad use of wording by me, jacketed is more appropriate, as opposed to shielded, however, there are a ton of wires that would be suitable, meet UL (or other standards), and have a 600V rating. However, unless you passing near another wire and/or the case, you often don’t require jacketing at all, bare wire may be suitable (just like a PCB), as long as the wire is supported. The op is asking about internal wiring, which could be many spots. I normally recommend for those not great at soldering to invest in a stripper that is good with teflon wiring and then use teflon wiring as excessive heat not not significantly damage the jacket.

1015 is often used as it is very cheap and provides better protection and colder guaranteed temperature rating than 1569 for 277V circuits.