In article , Alex Williamson
wrote:
The curio is that banana plugs make a 'pressure contact' with their
sockets. As does screwing down a grub-screw connection between the
wires and the plug. Hence if this is unsatisfactory and means a
grub-screw won't do, then the implication is that banana plugs won't
do at all - regardless of if you choose to connect the cable by crimp.
:-)
[snip]
Interesting; however, given that Silver Spiral 2 cable costs £30/m, I'm
keen to ensure I'm not wasting my investment on cable be using cheapo
banana plugs.
That is perfectly understandable and sensible as a desire. However it may
be that the makers/sellers of expensive connectors are exploiting this
wish...
The problem here is that your reaction is correct in wishing to make
effective use of what you have, but that the makers are not giving you the
information you would require to assess how to do this correctly. Thus you
may end up feeling you have to spend extra cash on their products as they
have kept you in the dark.
It's obvious from the physics that a QED Airloc crimp is
a better connection than just screwing the ends into a 24k plated
bananas plug
Is it? What "physics" are you referring to above?
The only "obvious" point I can think of is an engineering one. That a screw
connection may suffer from the screw becoming undone. In practice, though,
both screw connections and crimped ones are simply pressure contacts that
may cause some flow.
Alternatively, if you mean the physical construction of the cable makes
screw impractical, then fair enough. However if this is the case then you
would be forced to choose crimp because the makers have arranged to make
screw impractical in this case, not because crimp is inherently 'better'.
(risking having wires not even getting surface to surface contact with
plug).
Crimp or screw, it seems probable that some strands in the bundle won't be
in direct contact with the connector surfaces. Hence if I understand your
comment correctly, the 'risk' is probably realised in both cases. However I
can't see that this matters much. The strands will, I assume normally be in
pressure contact with each other.
I assume the maker's implication is that the crimped connection will give a
contact resistance that has a lower value and/or is more ohmic. However I
am not currently aware of any evidence that this arises either at all, or
at a level that means a practical difference which has any significance in
the context of making speaker connections. Not sure what other 'physics'
would be involved.
Of course, a poorly made screw connection (or crimp) would give a worse
connection. Ditto for one that has degraded or become corroded. However we
would then be comparing a poorly made or degraded contact with a well made
one, not screw with crimp as such.
In an industrial or commercial context crimp may well make better sense
than screw as the process can be quicker and cheaper in quantity once you
have the tools, and you don't have to worry about loose screws. However for
domestic use I have my doubts that this is a good reason for preferring
crimp.
Unfortunately, my experience is that cable manufacturers often use physics
as a form of 'technobabble'. Typically making generalised statements that
draw points well out of context. The concern here with contact resistance
is a typical example. The contact resistance can be expected to be tiny
compared with the actual resistance of the cables you are using. And even
tinier compared with the speaker impedance. The difference between the
crimped and screwed versions would probably be even smaller.
Much the same can be expected to be the case for any contact
nonlinearities. With a decently made connection these will be between 'nil'
and 'tiny compared with the amp and speakers'.
Hence by making vague and sweeping statements about contacts, and omitting
the context, they can make their claims seem far more significant than they
are likely to be in reality. If they gave you the context and some measured
results, you might not buy their connectors if it does not support their
claims and implications. Yet, strangely, they seem not to give this
information to enable you to decide on a well-informed basis... :-)
I didn't see any measured values of the the contact resistance for their
crimped connections. If you are interested in their plugs, perhaps you
could ask them for this, and their comparison values for a few meters of
their cable, and for a well-made screw connection (and perhaps for a
soldered connection).
Slainte,
Jim
--
Electronics
http://www.st-and.ac.uk/~www_pa/Scot...o/electron.htm
Audio Misc
http://www.st-and.demon.co.uk/AudioMisc/index.html
Armstrong Audio
http://www.st-and.demon.co.uk/Audio/armstrong.html
Barbirolli Soc.
http://www.st-and.demon.co.uk/JBSoc/JBSoc.html
Wanted: 24 * QED Airloc Banana Plugs [+ fitting]
Linear Mode
