hookup wire ratings in headphone amps

mete · 892

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Offline mete

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on: June 17, 2024, 03:32:11 AM
Is there any reason using anything thicker than 26awg (600V, 200C or teflon, e.g. AlphaWire 2853/1) in headphone amps other than the connections to the heaters ? As far as I see the resistance is less than 3x of 22awg (and 4x of 20awg), current rating >1A I believe ~2A (for 10C rise). Is 22 or 24 (only) preferred because of ease of handling ?



Offline Paul Birkeland

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Reply #1 on: June 17, 2024, 05:08:17 AM
Heaters and to some degree mains wiring can be a little on the demanding side.  From a kit standpoint, 26 AWG wire can be a real pain to strip, so we provide something a little bigger.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline mete

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Reply #2 on: June 17, 2024, 05:14:14 AM
Heaters and to some degree mains wiring can be a little on the demanding side.  From a kit standpoint, 26 AWG wire can be a real pain to strip, so we provide something a little bigger.

OK, good points, thanks.



Offline Doc B.

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Reply #3 on: June 17, 2024, 05:39:56 AM
It's not clear to me what you are saying about the resistance of the wire. To be clear, the resistance for a given length of wire increases as the diameter decreases.
That is, the higher the gauge number the higher the resistance per meter. For the short runs of signal carrying wire in a hand wired amp it is not too big a deal to go a gauge or two smaller. For long runs and high currents it is a big deal.

This has little to do with ease of use. As PB points out small diameter wires get tricky to strip, particularly when insulated with Teflon. They are also more prone to getting nicked from poor stripping technique, which often leads to a break in the wire just inside the insulation.

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Offline mete

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Reply #4 on: June 17, 2024, 05:57:09 AM
It's not clear to me what you are saying about the resistance of the wire. To be clear, the resistance for a given length of wire increases as the diameter decreases.
That is, the higher the gauge number the higher the resistance per meter. For the short runs of signal carrying wire in a hand wired amp it is not too big a deal to go a gauge or two smaller. For long runs and high currents it is a big deal.

This has little to do with ease of use. As PB points out small diameter wires get tricky to strip, particularly when insulated with Teflon. They are also more prone to getting nicked from poor stripping technique, which often leads to a break in the wire just inside the insulation.

I meant the same about the resistance. If I am not mistaken, R_26awg < 3 x R_22awg per same length. Because very short lengths are used, I thought it wont be an issue.

I thought, because it is thin, it might be harder to route (like a stranded wire), but it seems that is not the problem. I use a wire stripper so I didnt think about the wire stripping issues which I definitely agree.




Offline Paul Birkeland

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Reply #5 on: June 17, 2024, 06:53:07 AM
R_26awg < 3 x R_22awg per same length.
No, the resistance of 26 AWG wire will be way, way, way higher than triple runs of 22.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man


Offline mete

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Reply #6 on: June 17, 2024, 07:26:52 AM
No, the resistance of 26 AWG wire will be way, way, way higher than triple runs of 22.

I was particularly using the example below. They are silver plated, I dont know if it matters, I did not check other cables from the same vendor.

AlphaWire 2853/1 is 26 AWG, 41 ohm / 1000ft
AlphaWire 2855/1 is 22 AWG, 16.2 ohm / 1000ft



Offline Paul Birkeland

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Reply #7 on: June 17, 2024, 03:25:09 PM
Yes, the 26 AWG is 41 ohms per 1000 feet, which is 2.5 times higher than the resistance of the 22 AWG wire.

Paul "PB" Birkeland

Bottlehead Grunt & The Repro Man