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Minimum Gauge of Silver Wire for RCA Interconnect

Napzca

Active Member
I am building a 1.5m pure silver interconnect and am trying to calculate the minimum diameter or awg required. Any ideas how to calculate this? I used a voltage drop calculator with 2V AC line out but I don’t know what current it is, I tried 0.5A current and I am getting 6% loss at 24awg.

Untitled by Napzca, on Flickr
 
Erm if this for an interconnect current won't be anything like 0.5A! More like 0.1mA (2v/20k as a typical example).
 
0.0001A sounds very low

It's an presumably an interconnect into an amplifier, not a loudspeaker lead!

Ohm's law rules, substitute your amplifier's actual input impedance (if known) for the typical 20k in the example above!
 
The input impedance of the amplifier is 47kΩ is that how much the amplifier of the DAC has to drive? Seems rather high when a typical speaker is 8Ω
 
The point is, the resistance of the IC is, compared to the input impedance of the amp', near certainly totally irrelevant. The V drop across the IC is going to be very close to zero.

Which is why it can't make any difference to the sound!
 
Emeritus professor Malcolm Hawksford school of computer science & electronic engineering University of Essex is also an audiophile who some years ago published a long paper on this very subject I tried to read/understand it. I failed miserably the complicated maths was beyond me & then some, I understand that some of his students involved also helped with listening tests. The end result as I read in a precis printed in a HiFi magazine is 0.5 mm diameter wire is the optimum whether silver or copper, my phono leads are 99.99% pure annealed 0.5 mm silver using the TNT Shoestring design however instead of cat 5 copper wire (0.7mm) I slipped silver wire into thin PTFE sleeve which was wrapped/braided around a core, the hardest part these days is finding long hollow boot laces, if I need to make more I will machine sew linen tubes of the correct diameter.
 
I have used 1mm silver and 0.5mm cables for homemade RCA cables purchased from hifi collective. The thicker wire gives a slightly harder but more detailed sound. The 0.5mm is softer but more rounded. Both are very nice though.
 
Here is the paper by professor Malcolm Hawksford. Cables do make a difference, both in the construction and the quality of the copper used.
https://www.stereophile.com/reference/1095cable
Some of the conclusions. Do read the whole thing.
6: Stranded conductors without individual strand insulation appear to be a poor construction when viewed by this model, as the loss field propagates against the strands and experiences discontinuities in air/copper boundaries that are inevitably random. This is comparable to a large-scale granularity where crystal boundaries possibly represent a similar structure at the microlevel, but within the copper. A single strand of large-crystal copper or multiple strands of insulated wire—the quality of this dielectric will be important—will behave more as a simple impedance.
Conventional theory and actual conductor performance merge: At a diameter of around 0.8mm, the conductor becomes closer to a low-valued ideal resistor at audio frequencies.

11: It appears cable defects have their greatest effects under transient excitation rather than within the pseudo steady-state of sustained tones. Transient edges are effectively time-smeared or broadened (albeit by a small amount), where this dispersion is a function of both the signal and the properties and dimensions of the conductors.
 
the hardest part these days is finding long hollow boot laces, if I need to make more I will machine sew linen tubes of the correct diameter.

HiFi Collective do actually sell hollow tubular cotton sleeving for this very purpose, and it's really quite cheap as well.
 
i used to make my own using silver wire or occ copper,cotton tubing etc.
these days im very happy using just good quality copper with a good shield especially if its for tonearm duties and good quality well shielded rca plugs.
that's really all you need.
 
I used to wonder if non-Litz style insulated stranded wire could suffer magnetic field self modulation of resistance. The actual effect must be tiny as HF radio transmitters, still low enough frequency that skin depth is significant, don't suffer from obvious wire generated PIM.
 
I used to wonder if non-Litz style insulated stranded wire could suffer magnetic field self modulation of resistance. The actual effect must be tiny as HF radio transmitters, still low enough frequency that skin depth is significant, don't suffer from obvious wire generated PIM.
Similarly, twin pair cable carrying current will generate Lorentz force on the conductors which will radially squash and stretch the cable insulation. That will cause the cable's inductance and capacitance to be modulated according to the current squared and so cause intermodulation distortion.

Horror! Cables causes distortion!

But if you calculate the magnitude of this distortion in real situations (I have), even in the worst case with current-hungry loudspeakers and cable with soft PVC insulation, it's many orders of magnitude below the distortion you get from other parts of an audio system including loudspeakers as the worst offenders.

Phew! A reprieve for cables!

Sometimes there are real effects which people worry about but whose impact is in reality negligible. I am always wary of academic papers which set forward the science but fail to ask "so, what is the magnitude of these effects and do they matter in real-life contexts?"
 


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