Georgelofi wrote,
"And I still challenge any member to show a publicly seen doc that a manufacturers fuse is directional."
ill take that challenge. The measurements of many different fuses in terms of directionality are provided on HiFi Tuning’s web site. Stock fuses, HiFi Tuning fuses, other fuses, they’re all directional. For both DC and AC circuits. Hel-loo! Furthermore the effects of cryogenic treatment are also measurable and contained in the HiFi Tuning data sheets. Isoclean fuses also come with a directional arrow.
geoff kait
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Regarding the aforementioned directionality-related measurements provided by HiFi Tuning, I recently posted the following in the ongoing Littelfuse thread:
Regarding the measurements described in the HFT paper (which Nonoise was
kind enough to link to earlier in this thread) which purport to support
the notion of fuse directionality:
1)Resistance measurements
related to directionality were provided for 16 different HFT fuses,
having current ratings ranging from 1.6 amps to 20 amps, as well as for a
few competitive fuses and standard glass and ceramic fuses (the
specific make of the "standard" fuses being unspecified). The
differences in resistance for the HFT fuses in the two directions ranged
from 0.000002 ohms to 0.000120 ohms. The differences in resistance for
the competitive fuses were a bit greater in some cases, with the worst
cases generally being the standard fuses, for which there was one
isolated case having a measured difference of 0.005200 ohms.
IMO those numbers are so miniscule as to be:
(a)Laughable.
(b)Very
possibly attributable to changes in the voltage of the battery in the
measurement meter, from measurement to measurement (each measurement
imposing a slight drain on the battery), and from minute to minute. Or
if the meter was AC powered, to the very slight differences in AC line
voltage that may occur from minute to minute, as various loads are
turned on and off at nearby locations.
(c)Very possibly
attributable to differences in contact pressure and contact area between
the meter’s probe tips and the contacts on the fuse. The paper presents
separate measurements of fuse resistance as measured in a fuseholder
(for just one direction), indicating that the direction-related
measurements were performed by touching the meter leads directly to the
contacts on the fuse.
(d)Perhaps even contributed to by
differences in the resistance of the measurer’s body, that would have
been paralleled with the resistance of the fuse if he or she had fingers
on the probe tips and/or the fuse contacts while the measurements were
being taken.
(e)If Geoff’s comments about all wires being
significantly directional are to be believed, then these differences
would be totally swamped by both the resistances and the alleged
direction-related resistance differences of the vastly longer associated
wiring. In the case of mains fuses, that would include the power
transformer and the power wiring in the component, as well as the power
cord and the AC wiring in and outside of the house.
I’ll say
also that the comments I provided on the HFT paper in the "Fuses That
Matter" thread (linked to in one of my posts earlier in this thread) do
nothing to provide confidence that these measurements were performed in a
methodologically scrupulous manner, that would rule out the kinds of
extraneous variables described in (b), (c), and (d) above.
Regards, -- Al |
Al, thanks for your astute arguments, in fact HiFi Tuning agrees with you that the differences are quite small and they state that the small differences do not seem to explain the (large) differences in sound between the two directions. By the way, HiFi Tuning is not the only aftermarket fuse co. to mark their fuses with arrows so it's not as if HiFi tuning is the only one company claiming directionality of fuses. So, you cannot actually win the argument by attacking HiFi Tuning. Be that as it may, I feel it’s only fair and relevant to point out that audio interconnects - and here I’m referring to unshielded ICs so as not to confuse anyone - are directional.... and easily demonstrated to be directional. Just like fuses, it’s how the wire of the conductor is manufactured that determines it’s sonic directionality. That directionality (of the metal conductor) is precisely why many high end audio cable manufacturers provide ARROWS on their cables to indicate the direction that current is flowing between components. It doesn’t take much of a lead of faith, except perhaps for died in the wool skeptics, to see that ALL wire is directional.
geoff kait
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Yes you are correct some interconnects can be directional, ones that have +&- conductors with a shield, that’s only connected at one end, that end should be at poweramp. But fuses are not shielded. And I still ask you or anyone else to post any manufacturers ad/doc that SAYS they are directional. "It’s all VOODOO" that you are promoting.
Cheers George |
George, please don’t put words in my mouth. I’m not referring to ICs with shields as that’s a different issue. I’m referring to ICs without shields. They are directional and have always been directional. And for the same reason that all fuses are directional. By the way I totally get the backfire effect. No worries.
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