For Tele Lovers!
How would an aluminum bridge plate compare with other Tele bridge plates?
To address this in detail would
require some twenty pages of information ranging from classical to quantum
mechanical functions! First, we must understand that the Tele bridge plate
serves two totally different functions:
A: The mechanical functions
"A" deals with the
behavior of compressed waves in a medium. Most -- but not all -- bodies
are more or less elastic. The greater the elastic properties and the lesser
the density of the medium the faster a pulse propogates throughout the
medium. Some aluminum alloys, cast Bell bronze and some steel alloys hardened
to Rockwell C60 would be an excellent choice for the bridge saddles. The
steel guitar makers are aware of this and use for their bridge saddles
either Dur aluminum or hardened steel. As you can see, we have quite a
few options for the bridge saddles, but when it comes to the bridge plate,
we are confronted with some different problems that cannot be solved without
causing other problems that change the performance of our beloved Telecaster.
This leads us right to B -- the electrodynamic functions of the tele bridge
"B"deals with magnetism,
eddy currents and the permeability of different alloys. Any metal close
to the coil of a pickup will interfere with the signal that is generated
by the vibrations of the strings. Cold roll steel has a high permeability
which will increase the output of the pickup, but due to its high eddy
current potential, reduces the highs and output. 440 magnetic stainless
steel hardened to Rockwell C60 has about the same permeability as Cold
roll and a much lower eddy current potential. 440 stainless, as well as
Cold roll, can cause at high volume levels microphonic squealing. 301
spring tempered stainless steel has a hardness of Brinell 382, not quite
as hard as 440 but hard enough for the bridge plate. 301 has the advantage
that it has neither a positive nor a negative permeability, and therefore,
does not interfere with the tone and the output of the pickup. 301 stainless
will not cause microphonics. Some brass alloys have excellent acoustical
properties. Due to their eddy current potential, it will have some losses
in output and highs. Brass will not cause microphonics. Titanium Grade
5 ( GAL-4V) seems to have excellent acoustical properties. I've not yet
had the chance to measure its electrodynamical function , and therefore,
I have no information available. If somebody can send me for a few days
a titanium bridge plate, I will measure the electrodynamic properties
and will post the result right here on the tdpri.
Now let's talk about aluminum.
While aluminum has some of the best acoustical properties it has, by far,
the worst properties to use for the bridge plate. It's like salt in a
soup -- small quantities can perform miracles but too much will ruin your
dinner. Aluminum has an extremely high eddy current potential and when
placed under a pickup ( grounded or not grounded) can make a humbucker
hum like a single coil, or make a single coil as quiet as a hum bucker.
This all depends on the thickness of the plate. At about .250 thickness
your single coil will be as quiet as a hum bucker, but you also lose about
60% output and about the same amount of highs. Leo used a .015 aluminum
plate under the pick guard of his 54 Strat to reduce some of the hum and
the buzz and take a little bit of the edge from the pickup, resulting
in a very musical, sweet tone.
Aluminum has some strange
properties, and it's the only commercially available metal I know of that
can eliminate the buzz caused by light dimmers. An inch thick copper or
brass shield cannot reduce the buzz caused by light dimmers but .003 thick
aluminum foil can! This is known some thirty years and the reason why
Belden introduced double shielded cable ( Copper braid plus aluminum foil).
There is one problem for guitar cords -- the double shielding makes the
cable too stiff . It helps quite a bit when you shield your guitar with
copper and aluminum foil.
Try this test-- wire a single
coil to a jack and plug it into your amp. Put the pickup on a table next
to your amp. Take an aluminum pan from your kitchen and put it slowly
on top of your single coil and watch the hum disappear!