Audio Cable, Wire, Solder
DIY and Ready to Use Cable
You have heard or read about Long Crystal,
Single Crystal, Long Grain or Continuous Cast Copper wire.
To my knowledge it all means the same thing. The process invented
in Japan, is correctly identified as Continuous Cast Copper.
I buy it on 10 pound spools. I re-wind it on special spools
and have it cryogenically treated. The treated
wire is quieter with improved low level detail resolution
and transient performance. It is the best conductor, I have
found, for all audio applications.
The OCCC wire can be used to Litz braid excellent Audio Interconnects
and Speaker Cable. Since the wire is reasonable priced and
Litz Braiding is easy to learn. I have posted information
so Audio DIY enthusiasts can make their own. I offer Advantage
Audio Cables for Audiophiles who wish to purchase them ready
made. I also offer Copper Content Solder. This is a
classic solder that uses a very reactive flux
and a eutectic blend of Copper, Tin and Lead. It is perfect
for vintage restoration in both audio and guitar amps. It
also offers better sound performance with the OCCC wire than
the modern silver types.
Braiding Litz Wire Interconnects and Speaker Cables
This discussion is to help audio constructors develop the
skills to braid their own Litzendraht wire. This form of "Litz"
wire was developed in the 1930s in Germany. Since this type
of wire construction offered very wide bandwidth with excellent
phase performance, its popularity spread to other countries
very quickly. Western Electric was using Litz construction
in military applications in the early 1940s.
True Litz wire construction consists of braiding or weaving
a number of insulated conductors. The braid construction is
based on taking an insulated strand and folding it back to
the center of the strand bundle. Some wire manufacturers will
twist a number of insulated strands into a spiral bundle.
Originally termed "pseudo" Litz construction, many
audio wire manufacturers now call it an "alternative"
Litz construction. It is certainly easier to manufacture but
it will not achieve the wide bandwidth audio signal transmission
performance of true Litz wire.
The easiest Litz braiding technique is called a flat braid.
It has been popular for centuries. It is used by women when
they braid their hair and leather workers to braid sandal
thongs or belts. Flat braiding requires a minimum of three
strands and can be used to braid a higher number of even or
odd strands. The highest number of strands that can be hand
braided is determined by the dexterity and skills of the person
doing the braiding.
Please understand that all my listening evaluations are based
on using tube audio products and loudspeakers with simple
crossovers and reasonable efficiency levels. I believe AC
signal or power transmission is the most appropriate audio
application for Litz wire construction. For that reason we
will discuss braiding techniques for interconnects, speaker
cables. Litz Braid can be used for power cords.
On the other hand, the performance of DC power supply and
ground lines will benefit from wide bandwidth, low capacitance
and DC resistance. Litz construction meets those needs quite
well. Since amateur audio constructors do not have to consider
labor costs in planning their efforts, they could use Litz
braid construction everywhere. This is the form of construction
I use in the audio equipment I build. I have been using hand
braided Litz construction with some success for years. My
experiences have led me to form certain opinions on basic
guidelines that should be considered:
There is an optimum type of wire for braiding audio Litz wire.
Solid core wire is the only type that should be used. Stranded
wire defeats or offsets the benefits of Litz construction.
Stranded wire is nothing more than a number of bare conductors
that are spiral twisted to form the conductor. This type of
wire construction has phase anomalies and mechanical resonance
that severely degrades audio signal transmission. Litz braiding
a poor conductor is an exercise in futility.
There is an optimum wire size or cross section for audio Litz
wire. I have had my best luck with 24 AWG to 28 AWG wire for
interconnects, speaker cable and hook-up wire. Using larger
wire sizes for power cord construction may work well. In interconnect,
speaker cable and hook-up wire, the larger wire sizes degrade
high frequency performance and do not provide the focus, soundstage
and low level detail resolution of the smaller gauges.
The current transfer capabilities and DC resistance of your
Litz construction are based on the wire size and the number
of strands you select to braid. In my experience whenever
you braid more than 18 strands, the audio performance suffers.
I think this is due to the increased mechanical resonance
of the Litz braid. Take the time to review the tables found
on the anlwire.xls spreadsheet. The first table shows the
cross section in nominal circular mills of various wire diameters
based on the number of strands used. The second table converts
the cross section to the closest AWG wire size you think you
need.
If you are using the vintage Western Electric wire, interconnects
braided with 2 strands positive and 2 strands negative sound
the best. This is also true if you use the Chimera Lab's OCCC
25.5 AWG wire. In very low level applications, you may prefer
three strands with one strand as a floating shield.
The best loudspeaker cable braid depends on your speaker's
efficiency. Loudspeakers with 95dB sensitivity or less seem
to work well with a braid approximating 16 AWG. This is 5
strands positive and 5 strands negative for the W.E. 24 AWG
wire or 9 strands positive and 9 strands negative for the
OCCC 25.5 AWG. Loudspeakers with higher efficiency seem to
work well with a braid approximating as small as 18 or 20
AWG. Please remember, this is just a recommendation. You hear
the greatest difference in sound performance in bass reproduction.
You literally select the strand combination that makes the
bass sound best to you.
The proper length for a braided cable is the shortest length
possible that maintains enough distance between components
to prevent sound performance degradation. For example, the
best loudspeaker cable length seems to be about 3.5 to 4 feet.
A shorter cable puts the amplifier too close to the drivers
and crossover components. Longer and you just increase DC
resistance and add capacitance to mess up your phase performance.
The optimum length for interconnects seems to be 1 to 2 meters.
I realize many of you have audio systems layouts that use
interconnects or loudspeaker cables as long as 20 feet. I
just don't get acceptable sound performance out of cables
that long. It might be due to the fact that I run all my interconnects,
speaker cables and power cords so that they never run or lay
on the floor. If you have any of your cables running that
way, you are missing a great opportunity to improve your system
by suspending or shortening your cables to get them off the
floor.
Tools and supplies:
A good soldering iron
A sharp wire stripper of the proper size(for the vintage Western
Electric cloth covered wire)
A solder pot for tinning the wire prior to making a solder
connection is optional but nice
Your favorite brand of solder
A small brass or stainless steel wire brush to clean your
solder joints
ScotchBrite abrasive pads or a fine toothed file to clean
or prep the jack
The audio connectors of your choice
A fixture to help you solder the wire to the jacks and/or
speaker connectors
Some suggestions on connectors:
The best RCA plugs are the ones constructed like the Vampire
800 series or the Cardas types.
These plugs have an outer body with a milled slot to provide
access to the center positive pin. Since the interconnect
Litz braid has 4 strands, the two positive are soldered to
the center pin and the two negative strands are soldered to
the right and left side face of the slot. You solder the negative
strands right at the front edge of the slot, positioning all
strands(positive and negative) to ensure they will have the
same wire length to the outlet of the connector.
The best speaker cable connectors are those that are made
of OFC copper. The choice of using spade lugs or banana plugs
or bare wire is up to you, but I believe a spade lug or banana
plug will offer you the best connection.
A simple fixture that you can
use for soldering and braiding:
Source a pair of cheap RCA jacks and 2 pairs of cheap 5 way
speaker binding posts. Find ones that have as little metal
mass as possible. This reduces heat transfer when you solder
your connections. The binding posts should have metal faces
that come in contact with your speaker connector.
Find some fiberglass or Bakelite terminal boards. Drill holes
in two of the terminal boards to mount the binding posts spaced
the standard 0.75" distance apart. Drill holes in two
of the terminal boards to mount each one of the RCA jacks.
You want to be able to position these in a clamping device
or on a piece of plywood so that the RCA jacks are 90 degrees
to the front edge of your table or bench top. The binding
posts should have their connector mounting surface parallel
to your table or bench top.
Don't use metal angles or chassis to mount the jacks and binding
posts. It will act as a heat sink and makes soldering connections
a miserable experience.
Some suggestions on soldering:
Make sure your soldering iron will run hot enough to make
good solder joints on the connectors. Modern RCA jacks and
banana plugs have thick walls. A 35 Watt or 50 Watt iron will
work the best. Use an 1/8" wide screwdriver tip for the
RCA jacks and a 3/16" screwdriver tip for the speaker
cable connectors.
Ideally, you want the iron hot enough so that you can count
to 5 seconds or less before the solder flows to make the connection.
Starting the braiding process:
Measure and cut the wire into the number of strands you need
for your interconnects or cables. Add 1.25" to the length
of the strand for every foot of cable length. A 3 foot braid
requires strands 39.75" long. If you are working in centimeters,
add 1 centimeter in length for eve 10 centimeters. A one meter
or 100 centimeter braid requires 110 centimeter length strands.
Speaker cables can use up to 9 positive and negative strands.
Most speaker connectors require two separate connectors. Your
final braid length is determined by when you have all the
positive strands and negative strands properly realigned to
finish your connections. Because of this it is advisable to
add 6 inches to speaker cable runs. When we cover the braiding
techniques this point will be easier to understand.
After you have your strands measured and cut, mount a connector
in your fixture. Strip the insulation from one end of the
strands. Strip about 1/8" for RCA jacks and about 1/4"
for speaker connectors. Using your soldering iron "tin"
the exposed wire and the solder points on your connector/s.
RCA Jacks - Butt the two tinned positive strands together
and solder them to the center pin of your RCA connector. Take
one negative strand and solder it to the right side face of
the slot in the Jack's shell or body. Solder the remaining
negative strand to the left side face of the jack's slot.
Make sure each strand has the same length from its solder
point to the rear edge of the Jack shell. This is important
because you are trying to make sure each strand in the braid
is the same length. Take your brush and clean off all the
flux residue on all the solder joints. Your next step is braiding
the cable.
Speaker Cables - Butt the positive strands together and solder
them to the positive speaker cable connector. Butt the negative
strands together and solder them to the negative speaker cable
connector.
Braiding the Cable:
RCA-Jacks - Have your fixture positioned at the front edge
of your working surface. Braiding is slow methodical repetitive
work. You will find being able to sit down while you braid
will help you achieve excellent results. Adjust the height
of your work surface accordingly.
The flat braiding technique is simple. It consists of taking
the outside right strand and passing over strands into the
center of the bundle. Then you take the outside left strand
and pass it over strands including the one you just brought
into the center. Then you repeat the sequence.
Braiding a four strand interconnect works like this. LN is
the left side negative lead. LP is the left side positive
lead. RP is the right side positive lead. RN is the right
side negative lead. The braiding sequence is as follows:
1. Pass RN over RP
2. Pass LN over LP and RN
3. Pass RP over LN
4. Pass LP over RP and RN
5. Pass LN over LP
6. Pass RN over LN and RP
7. Pass LP over RN
8. Pass RP over LP and LN
At the end of this braiding sequence, the strands are oriented
exactly like they were at the start of your braiding sequence.
The left negative, left positive, right positive and right
negative are in the same position for connecting the braid
to the exit RCA connector.
So you can see a braid sequence length depends
on having the strands back in the same orientation as when
the start of your braid. The more strands you braid the longer
the braid distance will be between proper orientation. The
other factor on braid distance between proper orientation
points is how tightly you braid the wire. A loose braid increases
the distance. A tight braid decreases the distance. A loose
braid provides the best sound performance.
Treat wire as if it is a delicate living thing. Wire conductors
have a molecular crystalline structure. We know certain processes
like extruding, hammering, bending and folding metal disrupts
or randomizes its molecular structure. Braiding wire in tight
bends can damage the wire's crystalline structure. You may
find this difficult to believe, but the difference in sound
performance is not subtle.
The secret to braiding the wire loose is to control the loop
size of your braid crossover. Pass the strand over the over
strand or strands so that the loop is between 3/4" to
1" long. Finish a braid sequence so that the wires are
back to the proper orientation point. Gently take your hand
and wrap it around your braid. Squeeze the braid and pull
your hand towards you to compress the braid.
Compressing the braid reduces the mechanical resonance of
the wire. Look at the wire samples sent with your order. Notice
that the wire bends are not tight and the braid still has
some air space between the strands.
On the samples you will notice that the loudspeaker cable
has a 2" long section where the positive strands and
the negative strands are braided separately. This is to facilitate
making good connections to you components. After 2" the
positive and negative strands are combined into a standard
braid sequence. This should be done on both ends of the cables.
Braiding audio cables using this these techniques offer the
home constructor the opportunity to create very high performance
cables at great savings. You can also apply these techniques
for internal hook up wire. It takes patience, dedication and
practice, to develop the skills to braid Litz wire. But the
results are certainly worth the effort. Executed properly
these Litz cables offer low capacitance, inductance and resistance.
They accurately transmit the sound of live music and that's
what audio is all about.
Magnet wire, especially OFC magnet wire works very well. Vintage
Western Electric cloth covered wire does to. The OCCC wire
I sell is the best I can find. With magnet and the OCCC wire
you have to burn the sprayed on insulation off, but its
worth it. Stay away from solid core wire with thick plastic
insulation. It absorbs the leading edge of the musical signal
and low level detail resolution suffers.