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As the guitarists among you will know, passive magnetic guitar pickups are *very* different beasts than active line stages in audio gear. In some ways, they are much closer to phono cartridges than line stages in their interaction with cables. Passive guitar pickups have an output impedance of around 4.5KΩ - 10KΩ and have a lot of inductance (1-9 Henries). That makes guitars very reactive with cable lumped parameters (series resistance, series inductance, shunt conductance, and shunt capacitance.) as well as with the input characteristics of the guitar amplifier. The guitar cable becomes a “tone control” of sorts for the guitar. We’re talking about producing, not reproducing, music and there is no such thing as “fidelity” when you’re talking about an instrument. I would not be at all surprised to learn that a guitarist felt that cable A sounded best for 10 foot lengths but terrible for 25 foot lengths, while cable B may be completely the opposite.
By contrast, a properly designed line output stage will have an output impedance two orders of magnitude lower than a passive guitar pickup and should be all but immune to the typical differences in cables. The exception being when and “audiophile” cable is purposely produced with excessive (atypical) capacitance or inductance (sometimes even hiding caps inside of blocks in the cable, as described below), making the cable, in effect, a really bad tone control.
Cable manufacturers like to talk about “skin effect,” something that comes into play in RF frequencies. Talking about skin effect at audio frequencies is like talking about the effects of aerodynamic downforce on a turtle.
Regards,
Fred
> On May 27, 2016, at 10:33 PM, [email protected] [EAC] <[email protected]> wrote:
>
> I thought I would pitch this into the barrel - this 'technology' carries on into the instrument cable universe with cables providing "built-in equalization" (which seems to be an assortment of roll-off caps built under a rotary switch in the cable head): http://www.ordiocables.com.au/product/neutrik-ultimate-plug-guitar-cable/ <http://www.ordiocables.com.au/product/neutrik-ultimate-plug-guitar-cable/> for those too lazy to build their own, and on and on.
> However, there is an unscientific but fairly in-depth presentation of cable capacitance, high-resistance connections, and other such quality-influencing issues on the Premier Guitar site - many of which really DO figure into the ultimate transmission of audio quality;
> Guitar Cable Roundup, Part One <http://www.premierguitar.com/articles/guitar-cable-roundup-part-one-page-2-2?page=2>
> <http://www.premierguitar.com/articles/guitar-cable-roundup-part-one-page-2-2?page=2>
> Guitar Cable Roundup, Part One <http://www.premierguitar.com/articles/guitar-cable-roundup-part-one-page-2-2?page=2>
> The naysayers are dead wrong: quality cables DO make a difference
> View on www.premierguitar.com <http://www.premierguitar.com/articles/guitar-cable-roundup-part-one-page-2-2?page=2>
> Preview by Yahoo
>
> I'm still not ready to shell out $39K for a cable tho.
> - T.
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