NOISE-FREE TELECASTER |
 |
The Whys and Wherefores of Making the Tele
Digital Ready
'Noiseless' pickups aren't the end of the story. New component swaps,
rewiring, and fastidious shielding lowers the noise floor. Herein, an overview
- with some thoughts on 'the electric', itself.
|
INTRODUCTION
As I was initially writing about my new Telecaster acquisition, I opened
up the panels to have a quick look-see at the cavities and internal wiring.
It was, in that brief instance, something of a surprise to see some rather
ill-formed solder joints and questionable connections especially coming
from The Fender Custom Shop.
But it would be with a more detailed examination, following my
written piece, I would know for certain
that the previous owner of this otherwise magnificent 1996 offering had been
inside, changing things around then changing them back
kind
of. Indeed, once I pulled the knobs, I further saw that the pots had been
changed using splined shafts of slightly different heights. This would
have never come out of any Fender factory that way no less from the
Custom Shop.
But yes, many people with even the most rudimentary of soldering skills
take on the rather small project of changing out the potentiometers
once they become scratchy, or sometimes, they simply want to
see what another resistance value might conjure in the guitars sound.
Still, there were additional signs that the guitar had been played with
more than the more common indications that the instrument had been played
on, for it was essentially immaculate. Internally, the blade switch had solder
loaded on terminals that would normally remain dormant, and a couple of those
eyelets had, indeed, been clipped not at the wire, mind
you, but the actual terminals, eliminating their apertures. I also noticed
a couple of minor variants in the wiring that functioned normally, but still
didnt represent what was common to Fender. And then there was the general
execution of the solder joints that remained in evidence. Not cold, per se.
But not good.
And yet
the guitar played on, pretty much as intended if with
some transient noise between a couple of switch positions
something
to be expected for a guitar dating back to 1996.
None of this conjured regret for having purchased this outstanding Custom
Shop Fender, naturally. Yes, while many purchasers would like or expect
the instrument to be perfection, right out of the box, I would be
undaunted as the plan was always to swap out the parts under the control
panel, in any event. It would be time, after all, even without someone other
than Fender messing with it. And, moreover, I knew that I wanted to further
lower the noise floor of an already quiet guitar
ITS ALL NOISE, ANYWAY
Indeed, for those parents of the World War II generation, all electrified
instruments (their term) represented the breeding ground for
noise by virtue of their sonic existence. And the music associated
with the new fanged was also noise, to boot. But for many of
subsequent generations, noise was, indeed, the point. Loud, raucous,
grating. Impolite. Such was the appeal. It was one long, windmill-strum sustain
of fuck you to all that came before. The Dorsey Brothers could
simply go fuck themselves with the slide trombone they rode in on
Such was the birth of Rock n Roll even if its Surf Music cousin
sounded much like it was spawned out of a church social, remaining polite,
conjuring the sandy-toed, heartthrob response of holding hands, rather than
the more pudendal throb of cumming inside. And somewhere in that metamorphosis
of escalating intimacy, virginal to carnal
was Rock n Roll.
Fast-wind tape to the future when tape, itself, would be abandoned
THE NEW NOISE IS LOW-NOISE
So many of us sit here, on this day, with digital recording facilities that
boast and generally deliver a huge signal-to-noise ratio and,
by extension, a broad dynamic range - sometimes approaching or topping the
100db mark, nowadays. And many of our circuit board instruments
from synthesizers to samplers also deliver with similar, low-noise
aplomb. Even more contemporary condenser microphones have, in this regard,
out-paced the classic and revered Neumanns.
But
there is the High Noise Potential of Low-Noise: Multiple,
multiple, multiple-upon-multiple tracks
My particular recording setup can serve up 255 raw audio tracks, 255 software
instrument tracks, and 99 external MIDI tracks. Shit-loads of tracks, in
short. The problem: Each and every track is its own little noise
generator, no matter how low in noise each individual track may spec
on paper (and a single track is, indeed, what they use to spec).
So, go Full Hog with your Digital Audio Work Station without
intelligence, and your actual noise floor will pull you back to that of an
analog cassette machine of 1973 without Dolby (kind of, sort of).
Personally, if youre running 250 tracks at a swipe, you may really
need to re-think the music, anyway (with precious few exceptions).
The extra tracks are generally there to print several versions
of a take perhaps to be comped later on to some clean
tracks. But even holding at, say, 24 tracks
noise can build
up. Yes, even in digital.
But the point is this: With all of our track availability, were afforded
the opportunity to build our noise, track by track not
only within the Digital Workstation, itself, mind you but with each
and every instrument (outboard noise generator) plugged into the individual
tracks be they synthesizers, samplers, microphones
or guitars.
In short, digital is not your low-noise elixir, by simple default. Your problems
are potentially compounded by the available access of your Six Inch
Tape on virtual reels.
 |
The control panel being inserted after the rewiring. Copper tape extends
underneath pick guard to meet yet more copper adhered to that underside.
The tight and narrow cavity also uses a clear layer of Scotch brand packing
tape, cut to size (over the copper) to keep any 'hot' components or wiring
coming into contact with the shield (ground). A bit more on this, somewhere
below ... |
QUIETING THE NOISIEST BEAST OF ALL
It is for the reasons I cited, above, that I can go though great pains (or
attention to details) regarding all sorts of circuits (and even the power
supplies that drive them). And Ill do so in the interest of even a
1 ~ 2 decibel improvement in the noise floor for, as I explained,
noise compounds, and the floor raises always heading towards the
penthouse. And a single, 1 ~ 2db improvement
tracked four times over,
say
yields that improvement, compounded, across the mix. And this
doesnt even consider the digital doubling you may employ
to thicken up the sound, out of the box, or in the mix.
But surely, the noisiest of all instruments known to man is the
ever-popular, electric guitar be it conventional or bass.
In fact, in pure engineering terms, the electric guitar is the biggest piece
of audio-generating shit one has ever laid their hands on. Requiring mounds
of boost to get a useable signal across multiple pickups none of them
isolated or buffered from one another before combining or
blending, with untamed inductances that vary wildly across variable
resistors (pots), further influenced by the load
theyre hooked into amplifier or console and additionally
impacted by the very cabling used for the transfer of their micro-mini signal
... electric guitars, indeed, suck.
Of course, the work-around for the above in theory would have
been active electronics, contained within. But at the time of the electric
guitars inception, that would have meant the rather impossible task
of cramming a series of vacuum tubes into the body, driven by a heavy transformer
(and yet another cord). And, with this, your Ash-bodied Stratocaster would
soon become
ash. And if the electric guitar had, instead, been created
in the Integrated Circuit (IC) days of the 1980s, say, the instrument might
sound similar yet decidedly different ... And ones pet
sounds may have been in notable absence. Likely, even.
For it is the very manifestation of piss-poor engineering, as an
Epic-Fail of high school Electronics class even for a
passive circuit, that guitarists use to get their sound
with many not even realizing theyre truly playing with
or tweaking a grand fuck-up of epic proportions, at its core. And
that carefully, pot-adjusted fuck-up is
their sound. Indeed,
a sizeable portion of the aural cues one uses to identify the instrument
as being an electric guitar in the first place is founded in
engineering defect and anomaly one that wouldnt be accepted
in the crudest of home-built, passive mixers. And yet
it is the sound
one clamors for independent of its laughability as an engineering
project.
Beyond this, for those of us who play electric (about 20% of the time for
me, maybe), we find ourselves comparing notes regarding the deliberately
imposed application of distortion. That is, how can we make this
thing sound like shit though less than complete shit in a selective
and tasteful kind of way? An upscale, snooty kind of shit, say. So clearly
given this, for the electric guitarist, the fact that one is playing
a Fire Safety Dont Do This With An Outlet wiring
scheme behind the scratch plate is of little concern.
But what can concern them
is noise. Though, their primary noise-related
nemesis is often hum at 50 or 60 Hertz, depending upon
where they live. And buzzes. Crackles. Pops. Snaps. Clicks.
The Hum Portion of The Program (not to be confused with buzzes,
by the way) is often the nature of the beast, tied to ground. In fact, one
old Nashville studio player whose name I cant recall to credit
made a device years ago that was comprised of a bare wire
with an alligator clip soldered to one end, and a pinky ring formed at the
other. When in the studio, hed slip the ring end on his
finger, and clipped the other end to the bridge plate of his Telecaster,
making himself the path to ground. Hum was decidedly diminished
and the buzzes would often disappear, as well. Rather effective, yes
but those Pete Townsend windmill strums just had to hurt.
But naturally, the relative need to cold water pipe ones
guitar is often reflective of the wiring particulars of the room, itself
... and what other devices surround you in that space inclusive of
whats sharing the circuit, relative to the amp. For the very notion
of isolation is alien to the electric guitar. Its very design
says, Go ahead. Fuck me. And it, in turn
fucks you.
Then there are the cereal-conjuring, snap, crackle and pops almost
invariably tied to the dirty, old men of guitars: The pots and switches.
And yeah bad solder joints, as well. While these welds
generally dont come from the factory (though dont absolutely
count on it), Im amazed to see otherwise competent setup
luthiers who cant lay down a clean solder joint to save their lives
one that isnt a pitted, grey blob of tin snot. And while they
may work for a time, doom looms ahead.
Beyond this, there is what I call the light surface noise of
an electric guitar circuit. This, again, can come from bad solder joints
and sloppy wiring practices that are also receptors to extraneous interference.
And Im not speaking of the obvious, lamp dimmer buzzes.
Im talking about a light micro-grit noise that rides shotgun,
along side the desired signal. This residual noise would often be lost in
the noise floor of analog - but no more, in the digital age. And just one
bad solder joint or leaky capacitor can be a prime contributor.
REWIRING THE CUSTOM SHOP TELE
So, there I would be, closely examining my new Telecaster, three-pickup
acquisition. A jumble of wires true to Fender form and a 5-way
switch (to accommodate that extra pickup). The switch terminals had the evidence
of at-home rewiring and at least one pot had also been replaced with
a shorter, splined shaft that would have never been installed by Fender in
a Telecaster. The course of action was obvious: Rewire the rewiring with
all new control components.
And while I was in the guitar anyway, Id fully shield the cavities
with copper. While a black conductive paint had been applied
by Fender, copper simply has a much lower resistance and far better path
to ground. Yes, aluminum can also have its benefit as it relates to rheostats
(light dimmers), say, so a hybrid of metallurgy may be entertained, as well.
The black conductive paint is still very good for the wiring tunnels that
are less accessible (applied with a Q-Tip), but the open cavities can always
benefit from the copper treatment.
By the way, in tests I conducted some years ago, when using
Noiseless pickups (such as in this guitar), there was no audible
or measurable advantage to using shielded wiring within when the body
cavities were fully potted - or shielded. Naturally, Im
speaking of solid body guitars. My hollow-bodied Gibson Byrdland is another
animal.
THE PARTS
Here, I wanted to be respectful to the original guitar. With this, I would
use two CTS potentiometers for both the volume and tone circuit. While
theyre generally regarded as being all the shit in the
guitar world generally preferable to Alphas, say, guitar pots are
as a genre adequate. As it relates to audio
applications, there are far better pots out there in terms of
construction, precision, tolerance, linearity, and longevity ...
 |
Really think the CTS pots are all the shit? Think again. The exteriors
shown here are quite reflective of their respective interior builds. |
But, again particularly as one who swaps out pots every 3 years in
any event I chose to remain respectful of this Fender Custom Shop
instrument. Two 250k audio taper pots from CTS were selected with
the tone pot being of the no load variety. Actually, a small
array or the pots were measured, from which two were selected. Most measure
lower than stated value.
As to the 5-Way switch, Fender was still using the generally excellent CRL
switches in 1996. I located one (along with most other parts) at
www.specialtyguitars.com
I always preferred these switches to what Fender would use in later
years, having a more defined detent in each position. Yet, many Strat players,
in particular, seem to like the more vague switch feel of the newer switches.
Me, Im a CRL man.
From here, poly film capacitors were selected along with a single
resistor to adjust the linearity of the volume pot for a more consistent
upper register at all volume settings, as well as the appropriate values
for the no load tone circuit.
For those not familiar, the construction of a no load pot simply
scrapes away a small section of the carbon element at the end of the tone
pots travel. This essentially takes the control out of circuit
and offers a little more top-end or bite at full rotation.
I chose to modify the volume pot response more as a matter of
form, as I most commonly record at the 75% ~ 100% pot position where
this modification would yield the most negligible of influence.
 |
These would be rather standardized values. The added components to the
volume pot keeps the guitar's tonal character more even throughout its rotational
range. Consider it a refinement - not a must, though can certainly be useful
when one 'rolls the pot' for dynamic swells. Values may be played with,
naturally. Here, both pots would be of a 250k value. |
The wire
Here, I use a 22 gauge solid core for the point-to-point
wiring behind the control plate and the stranded core variety for
wiring that leads to the control plate, inclusive of any ground wiring
I completely toss the string wire used from the underside of
bridge plate (compressed against the wood) to the control plate. Its
uninsulated - not so much as a lacquer coat and can so easily touch
the hot side of things, even as you reinstall the control plate.
So, a stranded and insulated piece is sent from the bridge
plate cavity (below the bridge pickup) and sent over to the control plate
section in place of the string wire. Naturally, the pickups are
already equipped with stranded core wiring
I used solid core for the point-to-point wiring at the control plate principally
because its shapeable and becomes its own, rigid
wire-management system. Neat. Clean. Easy to trace back should something
ever go amiss.
One may use any brand of wire for this application even the
reprocessed wire they sell at Radio Shack in three colors, as
the spectral audio signature of an electric guitar is not one of high-end
refinement, in any event
But
as it relates to the solder
Okay
I know youre going to get your solder at Radio Shack, anyway.
Its so conveniently around the corner. But let me state, flat out,
that in more recent years its probably the worst solder
Ive ever encountered. Its as if its core isnt rosin, but
contaminant. You can keep on resoldering the joint or try but
once the joint is dull, you really have to remove the solder not simply
add more to get a clean joint.
But given that youll likely use the Radio Shack variety anyway, make
sure all connections are really clean even sanded before you
make your approach. And yes, sand the back of the pots where you make some
ground connections being real careful not to get any sanding debris
in the pot. In fact, mask off the open aperture near the terminals
along with any smaller holes you may see to the sides. Use a new, package-fresh
soldering tip properly tinned and heated fully. All of this, no matter
what solder you use
But I would advise some other brand of solder, in any event Weller,
whatever. Most anything other than Radio Shack. Make it a light solder
youre not doing pipe welds, remember. That designed for circuit boards
is fine yes even for switches and pots.
As to the added switch on the control plate its
a mini SPST, two-terminal switch. Here, you may pick that up at Radio Shack.
Their simple switches are perfectly fine. As used here, its the one
that comes with four colors of switch covers (that I dont use, keeping
it chrome).
As to the copper tape, I get this from
www.stewmac.com
The adhesive back is miraculously as conductive as its front
much better than the black conductive paint. And, if applied
correctly, I have found no need to solder the seams across the tape overlays.
Not for years. I use both the 2 variety, as well as the ¾
size for the sides of the body cavities. The ¼ size is useless
unless you want to wrap your pickups not at all advised as it will
alter the sound of the pickups
significantly.
Aluminum tape (at any hardware store) may be used in conjunction with the
copper variety particularly on the underside of the pick guard, if
desired. Think of a layered hybrid. Any order in the layer is fine.
 |
Copper tabs that extend to the top of the guitar surface meet their metalic
companions at the underside of the pickguard and bridge plate (containing
the bridge pickup). It's not actually necessary to fully shield the pickguard's
underside - just enough to create 'enclosed boxes' where the pickups live.
See the stainless screw at the bottom of the bridge plate well? That secures
a new stranded and insulated ground wire - replacing the stock (and naked)
'string wire' that's merely compressed between the bridge plate and wood.
HOT TIP: Top the copper tape off with Scotch brand packing tape (not the
cheaper off-brand, drug store equivalent). It will prevent any curl-back
of the copper tape and - as it relates to the narrow control panel 'slot'
- it will prevent your hot wiring from touching ground. Just remember - keep
the extension tabs on the guitar's top surface naked. They have to make an
electrical connection to the pickguard and bridge plate.
Also provide a small cutout in the copper tape where the screws attach
the pickups to the pickguard - while also having some copper way from the
pickgurad aperture at the neck pickup. You don't want that pickup's metal
shield (on the Tele) to make contact with any copper. Trust me. |
THE FINAL ANALYSIS:
Upon the completed component swap and rewiring, I compared the guitars
residual noise to that of a fully shielded dummy circuit that
replicated the load of the guitar. Upon jack insertion and cranking
the amp up to full tilt the only detectable noise component was in
the amp, itself. At more reasonable recording levels, the combo was so quiet,
residual room noise would become the larger issue. And for direct injection
through an amp simulator, say there simply was no issue. Indeed,
the guitar had gone
digital. For all practical purposes
noiseless.
|