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Old 27th Mar 2019, 9:39 am   #577
Craig Sawyers
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Join Date: Nov 2010
Location: Oxford, UK.
Posts: 4,941
Default Re: Audiophoolery?

Quote:
Originally Posted by Top Cap View Post
The Null Tester reveals all
You can advance to the 20 minute point if you just want to see the testing of different cables.
https://youtu.be/ZyWt3kANA3Q?t=1
That is very interesting - thanks for the link.

Personally I use 95% braid coverage star quad at £1.73 per metre https://www.canford.co.uk/CANARE-L-4...BLE-Deployable

And Neutrik EMC series XLR's.

I use Russ Andrews speaker cable. The principle reason is that I have actively crossed over Linkwitz LX521 speakers - so a five channel active crossover, and five channels of power amp, per speaker (Hence balanced signals to reduce the chance of hum loops). The reason for the RA braided speaker cable is that the external magnetic field is tiny (I've measured this), so running multiple cables in the same sheath means that there is very little coupling between the drive unit signals. But by virtue of the external field being tiny, by reciprocity the have very little RF pickup too.

The other thing that manufacturers of esoteric and punishingly expensive cables miss is that the signal has gone through hundreds of metres of bog standard balanced cables and hundreds of vanilla op-amps (such as the NE5532) during the recording process.

The only thing that the cables have to do is prevent ingress of RF from the environment, and the cable construction does have a role to play. But beyond having a high coverage copper braid screen and an internal twisted pair or star quad construction, there is little more to do.

I got involved in standards work in my own lab, and the question arose about what cable to use to wire up things like a 7-decade Kelvin Varley divider. So I phoned up NPL and asked. They said Van Damme star quad (about a couple of quid a metre). I said "what? I though you'd be using Goretex jacketed Teflon insulated wire". "Not for regular measurements; we only use that for the heated oil bath standards because it is immersed in hot oil for decades". What about spades? "We buy regular RS spades - but we do send them to Johnson Matthey to have the tinning chemically removed so we actually use copper spades. But that is simply to remove thermocouple effects". Which is of course critical for DC standards work, but has no relevance to AC stuff like - er - audio.

Craig
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