oregonpapa OP 1,193 posts 10-07-2016 4:11pm ^^^ So then geo ... Can assume that you're tired of discussing fuses? :-)
Actually no. I was anticipating your questions. ;-)
|
Okay, so does that mean that the "proper" direction of a fuse can be measured? Based on the comment and findings provided by Atmasphere that I quoted on 8-3-2016 on page 49 of this thread, and consistent with the second of the two comments by Warren of ARC that I quoted in my previous post (dated yesterday), in most (but not all) cases I would expect that if a fuse is tried in a given component in both directions the direction in which the least voltage exists between the two terminals of the holder would be preferable, if a difference in voltage does in fact exist in a particular case. However, implicit in Atmasphere’s findings is a strong possibility that that direction may not turn out to be the same if the two insertions are repeated and re-compared. Regarding the measurements that have been published by HiFi Tuning, I provided detailed comments earlier in this and other threads. The bottom line being that they provide no information that would be useful in predicting directionality, or that is even supportive of its existence when looked at quantitatively. IMO. Regards, -- Al |
Almarg wrote,
"Regarding the measurements that have been published by HiFi Tuning, I provided detailed comments earlier in this and other threads. The bottom line being that they provide no information that would be useful in predicting directionality, or that is even supportive of its existence when looked at quantitatively."
Al, actually that's not true. Not even close. Let me direct your attention to the conclusions provided on the HiFi Tuning Data sheets.
HiFi Tuning fuse data sheets - Interpretation of results (excerpt), taken from the data sheets
1. There were measurable differences in fuse direction for all fuses measured, including HiFi Tuning, Isoclean and non audiophile off the shelf fuses.
2. Measured differences were in the range of 5%.
3. Cryogenically treated fuses gave the best results.
4. For DC applications use solder type fuse or cryo’d HiFi Tuning fuse.
5. Differences were measurable and audible. Fuses sounded better in one direction than the other.
6. Measured differences in fuses don’t explain the sonic differences (which were greater than what the measured differences would suggest). (My editorial comment)
7. Fuses with smaller dimensions gave better results than larger fuses of the same value.
8. High end fuses gave better results than ordinary off the shelf fuses.
Cheers,
geoff kait machina dynamica
|
Just as not all audible differences are measurable, not all measurable differences are audible. The following is quoted from a post I made on 4-8-2016 in this thread: https://forum.audiogon.com/discussions/quality-and-security-of-littelfuse-products?page=2
Regarding the measurements described in the HFT paper (which Nonoise was
kind enough to link to earlier in the 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 |
|