Recommend low-resistance 20 AWG hookup wire

[mtl777]

Hey guys, I would like to get your recommendations for, of all things, hookup wire! The audio signal will be passing through this wire so it needs to be low resistance. The conductor can be either solid or stranded but it needs to be 20 AWG. The points I am hooking up in the circuit are 10 inches apart. Do I need exotic silver-plated wire or is that overkill?

BTW, I saw a table saying that 20 AWG copper wire has a resistance of 10.4 Ohms per 1000 ft. Is that a standard for any copper wire or are there higher quality copper wire with lower resistance than that?

Thanks in advance for any help!

[star882]

Use thicker wire for less resistance.

[kevinkr]

Resistance is a function of the gauge and it is a constant for copper of common purity levels, silver plated wire will not affect that significantly.

Better to spend your money on irradiated pvc or teflon insulated wire. I prefer stranded, but many prefer solid.

If you really need lower resistance (and I am betting you don't -do the math) then you need to use a larger gauge wire. I could make some crack about superconducting wire, but won't..

What sort of signal is it that a short conductor's resistance is a big concern?

[jleaman]

you need snake oil.! I heard some where in china on ebay sells it. It's a must!

[mtl777]

Originally Posted by kevinkr

Resistance is a function of the gauge and it is a constant for copper of common purity levels, silver plated wire will not affect that significantly.

Better to spend your money on irradiated pvc or teflon insulated wire. I prefer stranded, but many prefer solid.

If you really need lower resistance (and I am betting you don't -do the math) then you need to use a larger gauge wire. I could make some crack about superconducting wire, but won't..

What sort of signal is it that a short conductor's resistance is a big concern?

I have an AD converter unit that allows me to select three different input gain settings (either input pot mode, trim pot mode, or fixed -15 dBFS reference mode) by means of jumpers. The jumpers are simply selecting the L/R channel pair of audio signals that will get to the PCM4202 ADC chip. The thing is, the jumpers are inside the unit and I often need to make changes in the settings depending on the kind of input I am feeding to the converter (e.g., input pot mode for unbalanced consumer -10 dBV sources or trim pot mode for balanced professional +4 dBm sources). So I would like to install an external DIP switch with the wires running from the jumpers to the switch. This would allow me to change settings conveniently without having to remove the ADC from the rack, unscrew the cover, etc. I know this is less than ideal, as the jumpers with their short signal path would be better as far as sonic integrity is concerned. Heck, if I didn't need to change settings at all, I could just solder a thick wire permanently in place of the jumpers for the particular setting that I would always use and never change. But such is not the case, and I think I can sacrifice a little signal degradation for convenience. I would not like to sacrifice too much signal for convenience though so I want very low resistance wire. I understand that the wire needs to be thick to have lower resistance, but I have determined that I can only use up to 20 AWG wire due to the connectors on the DIP switch being so small and close to each other. I would not be able to solder any larger wires on them.

In summary, I need the wire to be very low resistance as far as 20 AWG could be, in order to minimize the signal degradation when using the switch compared to using the jumpers directly. Of course, the quality of the switch is another issue, but let's take things one at a time.

[jrenkin]

What if you mounted a relay switch inside the cabinet? Then you could control it from outside, and the long wires would not carry signal and you wouldn't have to worry about it.

[mtl777]

Originally Posted by jrenkin

What if you mounted a relay switch inside the cabinet? Then you could control it from outside, and the long wires would not carry signal and you wouldn't have to worry about it.

I'm interested in this solution, thanks! I don't know much about relays. Could you please give details describing the exact part I need to buy based on the following info:

There are six jumpers, JP1 to JP6. They are all on one row. The input pot mode is set by turning on JP1 and JP4. The trim pot mode is set by turning on JP2 and JP5. The fixed -15 dBFS reference mode is set by turning on JP3 and JP6. Thus, each of the three modes is set by turning on a pair of jumpers. I have already bought a 3-position DPST switch. Will I be using this in conjunction with the relay?

On the other hand, I haven't totally given up on the "wires" solution, so other posters please keep your recommendations coming on that.

Thanks again!

[jrenkin]

Originally Posted by mtl777

I'm interested in this solution, thanks! I don't know much about relays. Could you please give details describing the exact part I need to buy based on the following info:

There are six jumpers, JP1 to JP6. They are all on one row. The input pot mode is set by turning on JP1 and JP4. The trim pot mode is set by turning on JP2 and JP5. The fixed -15 dBFS reference mode is set by turning on JP3 and JP6. Thus, each of the three modes is set by turning on a pair of jumpers. I have already bought a 3-position DPST switch. Will I be using this in conjunction with the relay?

On the other hand, I haven't totally given up on the "wires" solution, so other posters please keep your recommendations coming on that.

Thanks again!

I have seen relay switching used for source selectors on amplifiers so the signal pathway is kept as short as possible. Essentially the same thing you want to do, but I do not have the expertise to design one. Maybe someone else can help you with that?

A simple google search for "relay switching for amplifier source selector" led me to this without looking past the first few sites. A finer tuned search or deeper look into this one may yield better results.
Simple yet versatile relay-controlled A/B switch box

Good luck!

[bob91343]

Of all the things to worry about, the resistance of copper wire at low current levels is right up there with whether cosmic rays are messing up my vintage 78 collection.

[jrenkin]

Originally Posted by bob91343

Of all the things to worry about, the resistance of copper wire at low current levels is right up there with whether cosmic rays are messing up my vintage 78 collection.

I don't know, I am sort of with him on this. What he is trying to do is tap off the internal jumpers and wire to an external switch. Maybe there will be noise pick up or something. I wouldn't worry much about the resistance, more that the signal wires may become little antennas and so a relay switch would keep the signal path short and inside the cabinet.