PDA

View Full Version : DIY Cables



thylantyr
09-29-2006, 02:14 PM
This is my DIY cable article.

Pics;
http://home.pacbell.net/lordpk/cables

http://home.pacbell.net/lordpk/cables/Belden_8760_TRS_Cable/

Pictures are numbered 1.jpg through xx.jpg to see
step by step progress.

I'm going to order Belden cable to make DIY audio cables.
I was previously using Belden 8760 from the old days and
I used it all. Time to re-evaluate my options before placing
an order.

It appears that a supplier called www.markertek.com has good prices.
For example, 500 feet of Belden 8760 cable is $70 at Markertek vs. $130 at Mouser.com

NOTE: Because this vendor seems to offer good pricing I will only choose cables that they
stock, so I'm only going to make the recommendation based on this fact.

Which type of audio cable do I want ?

* I want a shielded cable.
* I want two signal conductors, for balanced {proaudio gear}, plus allow un-balanced {home audio} interconnects.
* I want 18 awg - 22 awg wire for reliability {thin wires break}.
* Bonus: A cable that supports digital signals if the price is low enough.

Google reveals
For unbalanced, many are taking the advice from this person here;
http://www.geocities.com/jonrisch/i1.htm
and buying Belden 89259 coax. Markertek doesn't carry it.
The Mouser price is 100 feet for $263, 1000 feet for $1900.

This is good stuff but I don't believe in cable audio voodoo where esoteric cables sound better.
The simple science behind cables reveals the truth. If you need to run a single interconnect at hundreds
of feet or thousands of feet then you need to look at better cables where higher frequencies such as digital interconnects will cause more problems than standard 20hz - 20khz analog audio.

Note:
Belden offers plenum and non plenum version of cable. Typcially the number 8 is the before the part number for
plenum version. ie, that coax cable 89259 is the plenum version of 9256. Plenum versions are high temp cables
and they use different insulation materials, typcally 'Teflon' which gives it the high temp rating and much
lower capacitance in the cable. The cost is huge for plenum. For example, Mouser charges $1900 for 1000 feet
of 89259, Markertek charges $195 for 1000 feet for 9259,
the non plenum version.

Audio Voodoo
According to the link above, Teflon sounds better, an opinion by the author. If you look at the cable resistance, inductance and capacitance
specs, it's the same. The 'audio specs' are the same for both types of cables the only real difference is
the material used to gain the higher temperature rating.

Specs on those two cables, 89259 & 9259

Belden 89259;
Nom. Characteristic Impedance: 75 ohms
Insulation Material: FFEP - Foam Fluorinated Ethylene Propylene
Outer Jacket Material: FEP - Fluorinated Ethylene Propyle
Nom. Inductance: .09 H/ft
Nom. Capacitance Conductor to Shield: 17.3 pF/ft
Nominal Velocity of Propagation: 78 %
Nominal Delay: 1.3 ns/ft
Nom. Conductor DC Resistance @ 20 Deg. C: 15 Ω/1000 ft
Nominal Outer Shield DC Resistance @ 20C: 2.6 Ω/1000 ft
Outer Shield Coverage: 95 %
Operating Temperature Range: -70C To +200C

9259;
Nom. Characteristic Impedance: 75 Ohms
nsulation Material: FPE - Foam Polyethylene
Outer Jacket Material: PVC - Polyvinyl Chloride
Nom. Inductance: .09 H/ft
Nom. Capacitance Conductor to Shield: 17.3 pF/ft
Nominal Velocity of Propagation: 78 %
Nominal Delay: 1.3 ns/ft
Nom. Conductor DC Resistance @ 20 Deg. C: 15 Ω/1000 ft
Nominal Outer Shield DC Resistance @ 20C: 2.6 Ω/1000 ft
Outer Shield Coverage: 95 %
Operating Temperature Range: -40C To +80C

Cables that meet my criteria
What I want is a good dual conductor foil shielded twisted pair with drain wire cable that isn't too pricey
and no sacrifice to audio for normal cable lengths, not hundreds or thousands of feet of a single path.
Two conductor cable gives me the option to make unbalanced or balanced cables by using the same cable.
Here is some ideas for cables.

Analog Cables

Belden 8760 [PE - Polyethylene]
Foil shield
18 awg
60 Ohm impedance
Insulation Material: PE - Polyethylene
Nom. Inductance: 0.18uH/ft
Nom. Capacitance Conductor to Conductor @ 1 KHz: 24 pf/ft
Nom. Cap. Cond. to Other Cond. & Shield @ 1 KHz: 44 pf/ft
Cable diameter: 0.222"

Price: 500' - $70

Comments: The cable diameter is big but it works fine with Dayton RCA
plugs and XLR connectors even with Flex tubing.

Belden 8762 [PE - Polyethylene]
Foil shield
20 awg
56 Ohm impedance
Insulation Material: PE - Polyethylene
Nom. Inductance: 0.18uH/ft
Nom. Capacitance Conductor to Conductor @ 1 KHz: 27 pf/ft
Nom. Cap. Cond. to Other Cond. & Shield @ 1 KHz: 49 pf/ft
Cable diameter: 0.204"

Price: 500' - $70

Comments: Similar to 8760 but 20 awg wire and a smaller diameter cable.

Belden 8761 [PE - Polyethylene]
Foil shield
22 awg
64 Ohm impedance
Insulation Material: PE - Polyethylene
Nom. Inductance: 0.2uH/ft
Nom. Capacitance Conductor to Conductor @ 1 KHz: 24 pf/ft
Nom. Cap. Cond. to Other Cond. & Shield @ 1 KHz: 47 pf/ft
Cable diameter: 0.175"

Price: 500' - $58

Comments: Similar to 8760 but 22 awg wire and a smaller diameter cable.

Belden 88760 series {plenum version of 8760 series]
www.markertek.com doesn't offer it.

Belden 9451 [PP - Polypropylene]
Foil shield
22 awg
45 Ohm impedance
Insulation Material: PP - Polypropylene
Outer Jacket Material: PVC - Polyvinyl Chloride
Nom. Inductance: 0.17uH/ft
Nom. Capacitance Conductor to Conductor @ 1 KHz: 35 pf/ft
Nom. Cap. Cond. to Other Cond. & Shield @ 1 KHz: 67 pf/ft
Cable diameter: 0.116"

Price: 1000' - $92

Comments: Markertek offers only 1000 foot rolls and 9 different colors.
Capacitance higher than 8760 series but the specs are fine for audio.
Price per foot is very good!

Belden 1883A [PP - Polypropylene Propylene]
Foil shield
24 awg
52 Ohm impedance
Insulation Material: PP - Polypropylene Propylene
Outer Jacket Material: PVC - Polyvinyl Chloride
Nom. Inductance: 0.17uH/ft
Nom. Capacitance Conductor to Conductor @ 1 KHz: 31 pf/ft
Nom. Cap. Cond. to Other Cond. & Shield @ 1 KHz: 58 pf/ft
Cable diameter: 0.123"

Price: 1000' - $84

Belden 82761 ['Teflon' {plenum}, FEP - Fluorinated Ethylene Propylene]
Foil shield
22 awg
42 Ohm impedance
Insulation Material: FEP - Fluorinated Ethylene Propylene
Outer Jacket Material: LS PVC - Low Smoke Polyvinyl Chloride
Nom. Inductance: 0.16uH/ft
Nom. Capacitance Conductor to Conductor @ 1 KHz: 35 pf/ft
Nom. Cap. Cond. to Other Cond. & Shield @ 1 KHz: 67 pf/ft
Cable diameter: 0.116"

Price: 500' - $100

Comments: Capacitance higher than 8760 series but the specs are fine for audio.

Belden 1800F [FHDPE - Foam High Density Polyethylene]
Highly flexible cable for microphone use
French Braid shield (95% coverage)
Bare copper wires, not tinned.
Copper strands are 42x40
24 awg
110 Ohm impedance
Insulation Material: FHDPE - Foam High Density Polyethylene
Outer Jacket Material: PVC - Polyvinyl Chloride
Nom. Inductance: 0.18uH/ft
Nom. Capacitance Conductor to Conductor @ 1 KHz: 12 pf/ft
Nom. Cap. Cond. to Other Cond. & Shield @ 1 KHz: 26 pf/ft
Cable diameter: 0.211"

Price: 500' - $270

Belden 1503A [PO - Polyolefin]
Foil shield
24 awg
38 Ohm impedance
Insulation Material: PO - Polyolefin
Outer Jacket Material: PVC - Polyvinyl Chloride
Nom. Inductance: 0.18uH/ft
Nom. Capacitance Conductor to Conductor @ 1 KHz: 53 pf/ft
Nom. Cap. Cond. to Other Cond. & Shield @ 1 KHz: 97 pf/ft
Cable diameter: 0.142"

Price: 1000' - $80

Comments: Capacitance higher than others.

Belden 1508A [PO - Polyolefin]
Foil shield
24 awg
50 Ohm impedance
Insulation Material: PO - Polyolefin
Outer Jacket Material: PVC - Polyvinyl Chloride
Nom. Inductance: 0.18uH/ft
Nom. Capacitance Conductor to Conductor @ 1 KHz: 31 pf/ft
Nom. Cap. Cond. to Other Cond. & Shield @ 1 KHz: 58 pf/ft
Cable diameter: 0.131"

Price: 500' - $62

Comments: This is interesting cable if you need flexibility,
expensive.

Digital Cables - [AES/EBU]
According to Belden, digital cables are excellent for analog use.
http://www.belden.com/TB65.pdf

Belden 1800B [FHDPE - Foam High Density Polyethylene]
Foil shield
24 awg
110 Ohm impedance
Insulation Material: FHDPE - Foam High Density Polyethylene
Outer Jacket Material: PVC - Polyvinyl Chloride
Nom. Inductance: 0.18uH/ft
Nom. Capacitance Conductor to Conductor @ 1 KHz: 12 pf/ft
Nom. Cap. Cond. to Other Cond. & Shield @ 1 KHz: 26 pf/ft
Cable diameter: 0.177"

Price: 500' - $100

Comments: Digital cables are designed to have low capacitance,
24 awg is small so the cable end may be more fragile than a bigger
awg wire.

Belden 1801B ['Teflon' {plenum} FFEP - Foam Fluorinated Ethylene Propylene]
Foil shield
24 awg
110 Ohm impedance
Insulation Material: FFEP - Foam Fluorinated Ethylene Propylene
Outer Jacket Material: LS PVC - Low Smoke Polyvinyl Chloride
Nom. Inductance: 0.18uH/ft
Nom. Capacitance Conductor to Conductor @ 1 KHz: 12 pf/ft
Nom. Cap. Cond. to Other Cond. & Shield @ 1 KHz: 26 pf/ft
Cable diameter: 0.165"

Price: 500' - $210

Comments: Same as 1800B except the plenum version cost 2x more. Same inductance and capacitance specs.

Partexpress Microphone Cable
Two center conductors {no drain wire}
24 awg
Blue PVC jacket
Bare copper braid, 92% coverage
No inductance and capacitance specs listed.

500 feet for $145

thylantyr
09-29-2006, 02:16 PM
Line driving article;
http://www.rane.com/note126.html

Explains how capacitance effect transmission of frequencies.

They are using Belden 8451 (34 pF/ft) as an example.
If your source is 600 ohm output impedance and 500 foot
cable, you are low passing your audio signal at 15.6 khz.

Lets see what happens with a 25 foot cable that has
200pf/ft of cable capacitance and a cheap source with
a 1000 ohm output impedance and a 10,000 input
impedance into your preamp or power amp. Will the high
capacitance cable work?

Fc = 31khz.

yep.

Lets do the math using a good piece of audio gear like
Parasound to see what happens.

The Halo preamp is rated for 60 ohms output impedance.
The Halo amp is rated for 47k ohms unbalanced.

Lets say I want to run a 200 foot cable that is rated for
200 pf/ft, the Fc = 66khz ..

**********

I bought some RCA plugs to sample and I like this one;
http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=091-1265

Using that 8760 [18 awg] audio cable, 0.222" thick, I was
able to fit the cable plus some techflex, tight fit but it fit.

http://www.partsexpress.com/webpage.cfm?&DID=7&WebPage_ID=161

The Dayon XLR's are nice too.
Male;
http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=092-362

Female;
http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=092-360

I like the flex boot on those. Gold plated.

You don't need heatshrink if you use the thick cable.
For those 100 mil diameter cables you can add some heatshrink if you want to make the joint tight.

*********

Dual conductor plus drain, how to wire it?

RCA to RCA
RCA Hot => one insulated conductor
RCA Gnd => one insulated conductor shorted to the drain
Drain wire => connect to RCA GND

RCA to RCA directional {two steps, one for each end of the cable}
1. RCA source cable end only
RCA Hot => one insulated conductor
RCA GND => one insulated conductor
Drain wire => connect to RCA GND

2. RCA destination cable end only
RCA Hot => one insulated conductor
RCA Gnd => one insulated conductor
Drain wire => not connected

The destination RCA won't have the shield connected
to prevent noise on the shield/drain wire from entering
the destination equipment.

XLR to XLR
XLR Pin 1 = Shield ground => drain wire
XLR Pin 2 = Positive balanced signal => one insulated conductor
XLR Pin 3 = Negative balanced signal = one insulated conductor

XLR to XLR directional {two steps, on for each end of the cable}
1. XLR source connector [typically female]
XLR Pin 1 = Shield ground => drain wire
XLR Pin 2 = Positive balanced signal => one insulated conductor
XLR Pin 3 = Negative balanced signal = one insulated conductor

2. XLR destination connector [typically male]
XLR Pin 1 = Shield ground => not connected
XLR Pin 2 = Positive balanced signal => one insulated conductor
XLR Pin 3 = Negative balanced signal = one insulated conductor

The destination XLR won't have pin 1 connected to
prevent noise on the shield/drain wire from entering
the destination equipment.

RCA Output to XLR Input
XLR Pin 1 = Shield ground => connect to XLR pin 3
XLR Pin 2 = Positive balanced signal => one insulated conductor to RCA hot
XLR Pin 3 = Negative balanced signal {now ground} = one center insulated and drain wire to RCA gnd

XLR Output to RCA Input
XLR Pin 1 = Shield ground => connect to XLR pin 3
XLR Pin 2 = Positive balanced signal => one insulated conductor to RCA hot
XLR Pin 3 = Negative balanced signal {now ground} = one insulated conductor and drain wire to RCA gnd

XLR Output to RCA with -6dB output gain
XLR Pin 1 = Shield ground =>one insulated conductor and drain wire to RCA gnd
XLR Pin 2 = Positive balanced signal => one insulated conductor to RCA hot
XLR Pin 3 = Negative balanced signal {now ground} = don't connect

I made my XLR to RCA connectors with a switch that connects pin 3 to pin 1 to allow selection of output gain.

Let me know if there is any errors in this post :p

More configurations here, figure 5.
http://www.rane.com/note151.html

thylantyr
09-29-2006, 02:17 PM
Ideal cables don't exist. In the real world you have
to match cables with application because you have
resistance, impedance, inductance, capacitance, skin
effect... etc.

I suppose the ideal cable would have;

*zero dc resistance, impedance @ all frequencies
*no inductance/capacitance
*can't pickup stray signals/interference

An analog audio cable {20khz} is 'easy' if the source has
low output impedance and the load has high input impedance. Usually product is made this way to reduce
loading effects. A manufacturer who doesn't design using
low output impedance and high input impedance will have
problems with cables. <light bulb> You now see an opportunity where cables can be perceived to have SQ
because the equipment used is poorly designed.

Imagine a company that sabotages their preamp and amplifier design in such a manner where a good cable will
not function, rather to make it work better you have to buy
the special cable. For example, the ABCXYZ preamp and amplifier. You purposely design it so the output impedance and input impedance will only work with your special cables to pass the audio signal without attenuation {low pass filter}.

Normally a person would never consider such a product that can't work with ordinary cables but if you have a
an established good reputation you can also convince people that your thousand dollar 'special' cables only work
best with your gear. /evil eh?

Under a normal situation, not an evil one, you can use
any cable with good results to pass the analog audio.

The cable model also includes inductance and cables have
inductance specs but the inductance on those cables
are so low that that Rane doesn't even include it their
'math' for line driving. Cable capacitance is the bigger
enemy and one should look at that spec as it plays a bigger
role in the low pass filter formula, this is assuming the
source and destination are properly designed, no funny stuff.

Regarding the funny stuff. For an unbalanced preamp output you may see opamp outputs used to drive the signal and usually you may see a 50 ohm to 200 ohm resistor on the output of the circuit to dictate output impedance of the product. This qualifies as 'low output' impedance.

I remember someone on a forum mentioning a few years ago that Alpine HU's had 10k output impedance and their amps had 47k input impedance. Double check. When I saw that, it raised the 'evil flag' as why they would do this?
10,000 ohms is not low output impedance and it's marginal
if you have long cable runs in the car. This makes interfacing more difficult if you choose to use a different amp that had less input impedance than 47k ohms. What if your favorite amp was 10k input impedance?

If you know the equipment specs first before buying cables then you can figure out if the cable needs to be special or not. Also, you shouldn't buy equipment with high output impedance and low input impedance if you want a good
interface between equipment.

If you have an output rated for 200 ohms or less and inputs
rated for 22k or higher, it's all good, a normal cable is fine.

For higher frequencies they try to standardize the impedance, ie 75 ohm coax for RF, for AES/EBU digital {proaudio}
the spec is 110 ohms but the tolerance on that spec is loose and cables made for those applications need the lower capacitance cables.

DC resistance is rated per foot. That is really not a big
concern either unless you plan to pass high current on a small signal wire. I don't know who needs to do this.

thylantyr
09-29-2006, 02:17 PM
So which Belden cable from markertek ?

The bang for buck cable seems to be the Belden 9451.
Price: 1000' - $92

The only issue for me is the thin diameter cable, 0.116".

I was using 8760 before and it has a 0.222 cable thickness and fits nice with those connectors,
the 9451 is 1/2 the thickness and how will you 'extra' strain relief the cable?

You could add layers of heatshrink or tape to thicken it up
in the connector housing but it may look ghetto.

Belden 8761 is thicker, 0.175" the price is good.
Price: 500' - $58

If you want to run AES/EBU digital signal or even SPDIF {cheat}, the Belden 1800B looks like a jack of all trades cable for analog and digital use. The cable diameter is nice,
0.177" and the price is good.

Price: 500' - $100

thylantyr
09-29-2006, 02:25 PM
Making audio cables is easy, some people complicate the process. Once you have everything in your hand it all makes sense.

Tools
Soldering iron, I prefer higher wattage 40W-60W.
http://www.radioshack.com

Solder {60/40 rosin core}
http://www.radioshack.com

I use these cutters;
http://www.pcpolyzine.com/0202feb/cutter.jpg

I use these strippers;
http://www.zenithair.com/kit-data/ra/images/elect11.jpg
Find one that strips the awg wire size you choose.

I use these plyers;
http://www.istockphoto.com/file_thumbview_approve/510930/2/Pliers.jpg

Audio Cables
Lets use the Belden 8760 as an example. That cable is 0.222" thick and it has 18 awg wire. It's beefy and when
mated with Tech Flex and these connectors below, the fit
is nice and the cables look professional, perfect fit without
heatshrink. Now if you choose smaller audio cables you
will have a gap between the cable and housing and that is fine but it doesn't look as sweet. There is no electrical issues with smaller diameter cables, just cosmetic issues
and maybe reliability issues with very thin wires, ie if the strain relief is not done well the constant plugging and
unplugging of RCA's can weaken the wires.

RCA plugs
http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=091-1265

For about $2 each, these are nice.

Tech Flex
http://www.partsexpress.com/webpage.cfm?&DID=7&WebPage_ID=161

This is optional, it's a jacket that you slide the cable inside
to make the cable pretty and look cool. If you want to make
DIY cables to sell to people, this would raise the bar on eye candy. Comes in different colors and sizes. I think I used the 1/4" size for the 0.222" cable.

Stripping wire procedure
There is many ways to do this, wire is cheap so experiment by cutting, stripping off wire until you get the hang of it.

First thing I do is to cut off about 1" of the cable jacket
using those strippers. The reason I use these instead of
ordinary wire cutters is because it just happens to have
a sharper and finer cutting blade. I use the cutter portion
of the tool {not the wire stripping portion} to score the
diameter of the jacket by gently squeezing and turning
the cable. If you pinch too hard you penetrate the inner
conductor insulation. Practice makes perfect. After scoring,
I use the regular wire cutter to peel the jacket away.
You can use any method to cut the jacket off.

Next, peel off the foil because you don't need it. You should have 1" of jacket material removed and you should
see two conductors of wire.

What you do know is unscrew the RCA plug to reveal the inside and you need to 'size it up'. Place the cable on the
RCA to see how much wire you need to trim off, you cut 1"
to examine how you will fit the cable inside the RCA.
What you are are looking for is to have some jacket material on the RCA cable clamps because later you will
use the plyers to pinch those clamps against the jacket material as it serves as a strain relief for the cable.

Pick one conductor for HOT {signal} and one for GND {shield}. In the example of 8760 cable, they are colored
black wire and clear wire. I use the black wire as GND and
the clear wire as HOT {signal}.

I cut the HOT wire to length so it fits on the RCA center
pin for soldering. I strip off a small portion of insulation
and I also strip off the all the black wire insulation starting
near the jacket end and twist the drain wire to the black
wire. Don't trim the drain/GND wire yet. Do it later.

When you dry fit the cable inside the RCA connector, the
jacket should be next to the strain relief metal clamps, the
HOT wire should have insulation but only a small bit on the end stripped off to reveal the actually wire and you should have the drain wire twisted to the stripped off black wire.

Soldering
I use a procedure called reflowing for soldering. The idea
is to use flux based solder like the one I mentioned and you pre-tin all the connections ahead of time and then later
you reflow the connections together by applying heat. It's makes soldering much easier than other methods.

Pre-tin the HOT wire, place the soldering iron on the wire and add some solder until you have good flow and don't leave the soldering iron on the wire for too long as it will start to melt off the insulation. Do some experiments to get
the hand of it. You don't want gobs of solder, just enough
to coat the wire and get good flow into all the tiny strands.
Usually this takes seconds with a hot iron.

Pre-tin the ground and drain wires that you twisted. This takes longer because the wire is thicker and it takes longer
to tin the wire. If you take too long you start to melt the plastic on the jacket and insulation.

Let the wires cool off and cut most of the drain/GND wire
so there is only a small piece there, long enough to solder
to the RCA clamp.

Pre-tin the RCA center conductor and the area in which you
plan to solder the GND/drain wire too.

Next, I place the cable near the RCA plug and solder the
HOT wire to the center RCA. I place the wire there and heat
both areas at the same time, add a tad of solder to get some flux and the wires should reflow together and it's done. Do the same for the GND wire.

Use the plyers to bend the RCA clamps on the cable jacket
as a strain relief.

On the other side of the cable, insert the Tech Flex {optional} tubing and bring it all the way to the RCA
end.

Insert the RCA cover and screw the RCA back together.

Repeat this step for the other side but insert the RCA
cover first because you can't do it later :)

If you want to make directional cables where the source
end only has the shield {drain wire} connected to ground,
then you need to label the cable so you know which end is
source {preamp} and with end is the destination end {amplifier}.

Tip: If you are a noob you might get frustrated with the
8760 cable as it is a tight fit and 18 awg is pretty big
for a tiny RCA, you might want to use the 8762 that is
slightly smaller in diameter and 20 awg.

CBFryman2
09-29-2006, 02:27 PM
I skimmed, Ill read it when I get off of work. Nice write up.

thylantyr
09-29-2006, 02:27 PM
On the PE forum, someone posted a link to some Monster Coax cable that is priced $198 for
1000 feet. Looks interesting if you need jack of all trades A/V cables {not balanced cables for proaudio}.

SV-RG6

http://www.monstercable.com/custom_install/productPageCI.asp?pin=294&LastPage=Video%20Interconnects

http://www.summitsource.com/monster-1000-ft-rg6-digital-75-ohm-coax-cable-white-part-mvrg6-mvrg6-p-4721.html

http://www.summitsource.com/monster-rg6-digital-75-ohm-coax-cable-white-sold-by-the-foot-part-svrg6-svrg6-p-4770.html

I can't find the tech specs for this cable so I don't know what the story is.

Also look at MV-RG6, 2Ghz is listed for $89 $ 1000 feet.

thylantyr
09-29-2006, 02:27 PM
For analog audio 20khz, cable capacitance plays the big role not the impedance of the cable. Lower cable capacitance is nice but it may be overkill for the given
application. The sources output impedance and input impendance of the equipment is also a variable in the math.

Cable impedance is more of an issue with high frequencies, ie Mhz or Ghz, see transmission line theory {google}. Coax {video} cable is 75 ohms, SPDIF {digital audio output} is 75 ohms, AES/EBU {proaudio} is 110 ohms but the spec is very loose on AES/EBU, +/-20% 88 ohm - 132 ohm. // rofl //

Im not a cable guru so do some homework to verify my babble. If the spec is loose, that
implies that the manufacturer has to design a receiver than can tolerate that range of
impedance mismatch, so some folks are using ordinary 75 ohm cable because it's so close
to 88 ohm and they run short cable lengths. It works. The ****-philes[tm] fear problems,
loss of digital bits and.or fugly digital signals that can be interpreted wrong by the D/A
converters. They don't want to take the risk so they will use 110 ohm 'digital' cable.

For SPDIF to AES interfacing, aka home audio CD player that connects to your
Behringer DCX which only has AES digital inputs, some of the ****-philes are modding
the Behringer by inserting a small 75 ohm to 110 ohm impedance matching transformer.
The mod is simple, you place this tranny on the PCB board where the AES signal inputs,
the other side of the tranny is now 75 ohm for SPDIF input. This is the politically correct
way to do it. In the world of high frequency, funny stuff can happen and you need to
match impedance.

For 20khz analog audio the impedance is really not an issue, the audio band is snail slow
compared to RF or digital transmission, you can get away with almost any type of cable,
even the cheap rat shack or home depot dollar audio cables work. The reason I don't
buy those cheap cables is reliability issues. How many times have you worked on audio
using the same cables and the constant insertion of the cable cause intermittent audio
problems because the cable weaken over time. Later you find audio intermittent problems and you have to debug the system and it comes down to bad cables.

Been there, done that. The RCA end where the cable meets the wire starts to 'break' and
you get intermittent contact and when wiggling the cable the audio cuts in and out.
When I was doing car audio, everyone was always tweaking on the systems and wires
broke like this. When I was looking for Belden cable decades ago the goal was to find
cheap twisted pair with heavy gauge wire to make them gorilla proof on handling. That is
why I picked the 8760, 18 awg wire cable.

Today, it appears to be a good choice as when I used it with Dayton RCA's and Tech
Flex, the fit was perfect, kinda weird eh? I was hoping to find better cable just because --- but those digital AES cables are 24 awg. Normally not a problem for permanent
installs, but for the DIY'er who likes to fvck with their stereos all the time, I don't want
the thin wire to break with abuse. /// lol ///

That cable is about 50 mils smaller in diameter than 8760 and to make it fit with the
Dayton RCA so it's tight you probably have to add some layers of heatshrink tubing
to thicken up the cable jacket on the end. No big deal, just another step in the RCA
making process.

If you are handing audio cables on a regular basis, the DIY microphone cable looks good.
The cable is very flexible, they don't tin the copper wires to keep it flexible and they use
alot of fine wire to make the whole strand, copper braiding which won't 'break' vs. foil
over time, and the rubber housing gives it resistance to abuse, cool for audio but cost a lot
of money, 2x - 3x more money than ordinary twisted pair.

For home audio, can you find a jack of all trades wire to do unbalanced, balanced, and
video ?

You can use 75 ohm coax cable for video, use it for analog audio but you cant use it for
balanced as in pro audio gear because it has only one center conductor, balanced requires two. You can find 'multi-wire' coax cable. It's smaller coax cables all inside a common
jacket. The question is, how stiff the cable as a whole? That Monster RG6 that the guy on PE recommended said its more flexible than RG59 coax, he likes it a lot. The price is cheaper than Belden 9259 coax, but you wont be able to do balanced interconnects.

I also found out that the Beldfoil {Belden's special foil} is more like metalized plastic so
it doesn't tolerate abuse like a microphone cable would be - but for permanent installs
it doesnt matter. I think it can handle a lot of abuse from what I can tell but not everyday abuse. ? Belden claims 100% shielding for RF using the foil, they also claim braided
shielding is 90% for the higher grade wire but braided copper is better for lower
frequency shielding. Double check, I thought that is what I read on the link I provided.

I don't think one has to worry a lot about this in an household installation where wires are
short and you don't have crazy interference problems and you dont do much tweaking
where cables are getting abused a lot.

In my case, perhaps your case where we mix home audio {unbalanced} with proaudio
{balanced}, the regular twisted pair cable would be fine for the analog interconnects.

What about the CD player digital output to proaudio input? If you choose this route
do you use AES 110 ohm cable or 75 ohm cable? If you cheat you can try AES cable to
interface the CD player to Behringer {or any pro audio equipment that is AES} and use
that same cable for the rest of the analog DIY interconnects. The problem I see is the SPDIF output might not be happy with 110 ohm cable vs. 75 ohm. I dont know what the
tolerance is for SPDIF and I dont know how picky the output is. You can use ~75 ohm
cable instead and hopefully the AES input can tolerate the mismatch, its suppose to handle cable as low as 88 ohm per spec. 75 is close to 88 : hehe:

But if you modd the equipment from AES to SPDIF then you should use 75 ohm cable.
You can buy an adapter to convert SPDIF to AES too.

The comedy gets worse. If you like the Behringer DCX2496 and later want the equalizer
DEQ2496 and use the DEQ on the front end, ie

CD player digital output -> DEQ -> DCX

then the DEQ has both AES and SPDIF interface -- rofl .. Most people are using SPDIF
output on the CD player into SPDIF on the DEQ, then DEQ output {AES} to DCX input {AES}. /// hehe ///

You can use 75 ohm to feed the DEQ then AES cable to feed DEQ -> DCX
It's comedy when trying to interface home audio digital to proaudio, but like I said .. people cheat because the AES spec is so loose. Nobody has complained yet, only the elite
golden ear ****-phile who worries about the impedance mismatch that may yield bit loss
or fugly digital signals. Keep cables short to minimize issues.

If proaudio is not in the equation, then one can use coax to do analog, digital audio and
video interconnects, ie that monster cable RG6 cable {vs. RG59}. When you
throw in proaudio into the mix you have balanced analog cable requirements that needs
two conductors, typically they use the twisted pair cable I mentioned, for digital
they use the lower capacitance AES cable.

I might make more sense to have two cable types for DIY interconnects instead of
finding one that does it all. I don't like stiff cables as in thicker coax, so you may desire more flexible coax like the Monster cable mentioned. Im sure someone else makes
some that is flexible, I dont have access to try all these cables. // rofl //

But with coax you need the special tooks to do a nice job, cost money for those crimpers.
With twisted pair no special tools are needed.

Then for the proaudio needs, maybe get the AES cable for analog and digital interconnects but you still have that SPDIF to AES issue think about.

thylantyr
09-29-2006, 02:28 PM
Trolling AVS forum reveals

People seems to steer away from Monster cable brand and
recommend this brand;

http://www.bluejeanscable.com/index.htm

For unbalanced audio, here is their recommendation.

Belden 1505F,
http://www.bluejeanscable.com/store/audio/index.htm

Specs here;
http://bwccat.belden.com/ecat/jsp/Index.jsp?&P1=undefined&P2=undefined&P3=undefined&P4=undefined&P5=undefined&P6=undefined

It's RG59 coax with double braided shield, 95% coverage.
Low capacitance, 17pf/ft.

The Markertek.com price is $287 for $1000 ...

28.7 cents per foot, plus tool cost and initial $287 investment.

FYI, 25' Blue Jean audio cable cost $53, the same cable DIY can be made
for $13 {same wire, same RCA}.

If you want the Tech Flex option, they charge another $25 for that 25' cable.
If you buy Tech Flex by itself it's $7 for 25'.

Blue Jean 25' cable w/Tech Flex cost $78.
DIY version $20.

Catch 22. You need the tool to strip the coax and crimp the cable.

http://www.bus.ucf.edu/cwhite/theater/diycable.htm

Other recommendations from this vendor is listed here;
http://www.bluejeanscable.com/store/shopbycable/index.htm

Cable Description
Belden 1694A "Brilliance" Precision Video Coax, RG-6 type; our favorite
Belden 7710A 3-cable bundled version of Belden 1694A, for Component/RGB use
Belden 7711A 4-cable bundled version of Belden 1694A
Belden 7712A 5-cable bundled version of Belden 1694A
Belden 1695A Plenum-rated (Teflon dielectric) version of Belden 1694A
Belden 1505A RG-59 type Brilliance Precision Video Coax
Belden 1505F High-flex Brilliance Precision Video Coax
Belden 1855A Miniature Brilliance Precision Video Coax
Belden 1808A "Brilliance" round flexible S-Video Cable
Belden 7700A "Brilliance" plenum zip-cord style flexible S-Video Cable
Belden 1800F Shielded twisted-pair balanced audio cable
Belden 89259 Plenum-rated (Teflon dielectric and jacket) RG-59 cable
Belden 8281 Large, old-style, inflexible analog video cable
Canare L-5CFB Precision video coax, similar type to Belden 1694A
Canare V3-5CFB Three-cable bundled version of L-5CFB, for Component/RGB use
Canare LV-61S Our most flexible video coax, RG-59 type
Canare LV-77S Similar to L-5CFB but stranded conductor, more flexible
Canare L-4E6S Star quad balanced audio cable


For balanced audio, here is their recommendation.

Belden 1800F
http://www.bluejeanscable.com/store/balancedaudio/

Markertek price is $510 for 1000' :eek: :eek:

thylantyr
09-29-2006, 02:29 PM
Forgot to mention

If you make DIY coax cables, don't use the Dayton RCA
I linked, you need RCA that is designed for coax.

Another option for RCA, Canare;
http://www.markertek.com/SearchProduct.asp?item=RCAP%2DC3A&off=2&sort=prod

You need coax strippers and crimpers.

thylantyr
09-29-2006, 02:29 PM
RG6 vs. RG59 debate

Standard RG6 Quad Shield for Component Cables?
http://www.avsforum.com/avs-vb/archive/index.php/t-438868.html

Larry Fine
08-25-04, 09:58 PM
If it were me, I'd specify an all-copper RG-59 for any interconnect other than RF.

Larry Fine
08-26-04, 09:14 PM
The only functional difference between the two is loss over distance for RF use,
and we're talking in the tens or hundreds of feet for the difference to become
significant. All-copper RG-59 is thinner and more flexible, easier to find RCAs for,
and possible to solder them.

Bill Lummus
08-27-04, 07:30 PM
There was a thread here several months ago where it was revealed, correctly so I believe,
that the triple shielded RG6 actually provided better noise rejection than the quad
shielded. There is a writeup about this on Belden's website. I think their brand name
for the good triple shielded cable is duobond. I'd look for that. It's cheap and easy
to get. I think you can find the exact numbers on blue jean cables website, they use
it too.

DominoGold
08-28-04, 04:26 PM
I snuck into another house under construction to see the type of RG6 they used.
It looked like copper rated at 350 Mhz and said "HDTV" labed right on the white cable.
This this is good enough for component cables?

Bill Lummus
08-29-04, 06:44 PM
I don't think so.
Why not get some of the >1 GHz Belden cable. It's cheap and very good. You can never
have too much bandwidth! And be sure that RCA's is what you need for the TV.
Some plasmas come with BNCs.

Marine2800
09-01-04, 10:51 PM
Hi folks,
Just weighing in with some information on the subject.
I am an industry professional and give tech advice to installers, end-users,
dealers, and specifying engineers everyday regarding cable and wire applications
in the Home Theater, Integration and broadcast market. A standard CCTV RG59
can transmit these signals perfectly over significant distances. I have used
coaxial cables as small as 26 AWG micro cables for transmitting these signals
clearly out to 150 feet. The only issue that may arise in long distances is the
timing of the cables. A TDR would be required to measure and cut the cables to
synchronize the timing. I have seen this start to happen at distances around 250 feet.

Composite, Component, S-Video are all baseband style video signals, a copper/copper
coaxial cable is the preferred construction for these signals. The braid can be
tinned copper also as in Beldens 1694A. Copper clad steel center conductors,
aluminum foil, and aluminum braid shields are not recommended for this type of
application. I have had multiple occasions where people have used RG6 quad shield
for rack interconnects and had issues with picture problems, replacing the cables
corrected the problems immediately.

A copper center conductor, aluminum foil shield, and copper braid is acceptable also.
Regarding the connector question, there are many non-solder style RCA plugs on the
market. These are compression crimp versions. The tooling is somewhat expensive so
if you are only terminating a couple of cables, solder style is cheaper.

If I sound like a know-it-all you have my permission to slap me
:D

Marine2800
09-02-04, 09:48 PM
I recommend using a cable constructed for the baseband signals. Steer away from
aluminum braid shield as in RG6-Quad and dual shield CATV cable. One gentleman
I walked through an image problem had 15 foot RG6-Quad runs with RCAs on a rack.
The quad shield was a bare copper center conductor and aluminum braid shields.
We replaced the cable with some quickly constructed RG59 serial digital cable
(Liberty Interflex-sd - a non-UL version of Belden 1505A) and radial compression
RCAs and he was in business with a perfect display. I ran tests on his old cables
and found they were perfectly fine as far as RF performance. Your standard component
video interconnects are usually copper/copper and work fine for the low frequencies
involved. For the distance you are running a component video interconnect cable is fine.
If you have a source for the RCA plugs and 75 feet of RG59 CCTV cable then you can
construct them yourself.

DominoGold
09-03-04, 03:34 PM
I think my low-voltage contactor only uses RG6 for everything, and specifically
warned me against using RG59 for anything. So, I'm confused.

Marine2800
09-03-04, 09:21 PM
Do not be confused. RG59 is just a smaller coax with slightly higher attenuation loss.
As a guide for example: A serial digital RG6 will successfully transmit a 37 MHz signal
up to 377 feet before the -3 dB threshold is reached. A serial digital RG59 will
reach 265 feet before the -3 dB loss is reached. Your contractor probably has loads
of RG6 and has to recoup his investment.

Bill Lummus
09-04-04, 08:34 AM
Sorry- I lost track of this thread for a bit.
I agree with everything Marine has said. This difference between RG6 and RG59 for a
short component video run won't matter as much as the quality of the wire. Steer
clear of the ultra cheap generic cables. I would recommend Belden 1506A or 1694A.
Neither of these are particularly expensive in bulk. From Mouser the 1694 is $70/100ft,
the 1506 is slightly more. If you don't have the equipment to crimp connectors on you
can always solder. One tip- run some PVC conduit everywhere you think a wire might go.
The home audio and home theater technology is changing but your room won't. This will
allow you to change the types of cables you are using without tearing up your room
again and again. Be sure the conduit is big enough to take a DVI connector at
a minimum.

Larry Fine
09-04-04, 07:05 PM
Originally posted by Larry Fine
If it were me, I'd specify an all-copper RG-59 for any interconnect other than RF.
I said it before, the Marine backed it up, and I'll say it again:

"If it were me, I'd specify an all-copper RG-59 for any interconnect other than RF."
RG-6 is better for RF use (even though I have dual RG-59's feeding my dual-tuner
D-TiVo's), but for audio and video, all-copper RG-59 is better. As long as you're
bothering, why not use what's better for the intended use?

Larry Fine
09-04-04, 08:22 PM
Originally posted by Bill Lummus
Larry- How about giving some specific examples. Not sure what you mean.
Examples of when I'd spec one or the other? Okay:

If I were wiring for cable, satellite, radio, or any other radio-frequency use
(basically anywhere F-connectors would be used), I'd want RG-6. For composite,
S-video, or component video, or analog or digital audio (basically anywhere RCA
plugs would be used (except for S-video-to-dual-coax)), I'd prefer a good RG-59.

In my opinion, RG-6 is only beneficial at radio frequencies. The thicker dielectric
and quad shielding do not lessen signal losses for any other signals.
RF signals are in the microvolt range, where reactances have a greater effect
on the signal, while audio and video are in the millivolt range, where I^2R losses
matter more. Copper is a better conductor than copper-clad steel
(except again, for RF, where skin-effect makes the core material moot), and it's
also a better conductor than aluminum. Some people call RF "magical", because it
seems to defy the laws of physics. Audio and video seem to behave a little more
"logically", electrically speaking. Plus, all-copper cable can be soldered,
and RG-59 is thinner and more flexible, and it's easier to find RCA connectors to
fit without adapters. I'd rather avoid adapters when possible; not because I'm
worried about "the extra connection" issues (if I were, I'd solder everything),
but to reduce plug and jack strain. YMMV, of course.

DominoGold
09-04-04, 08:59 PM
Interesting discussion here.... the thing I'm struggling with is the general
perception that RG59 is "old" and RG6 is the newer and better cable to use for
everything.

For example, this thread basically summarizes everything people have told me
up until now.

http://www.handymanwire.com/ubbthreads/showflat.php?Cat=&Board=UBB2&Number=104966&page=19&view=collapsed&sb=11&o=&fpart=1

Marine2800
09-04-04, 09:32 PM
For the signals and length of transmission you are describing the cable size is
really irrelevant. A 26 AWG micro coax with a tinned copper center and tinned
copper braid will perform adequately. I would recommend a beefier mini though, like
Belden 1855A or an equivalent. These perform superbly to 300 feet on the above signals.
They save a lot of space in a conduit and can be purchased in multiples under one jacket.
RG6 Serial digital - Belden 1694A 3 GHz/100 feet = 10.67 dB loss
RG59 Serial digital - Belden 1505A 3 GHz/100 feet = 13.40 dB loss

This sure does not appear to be twice the performance. For base band style video
signals such as composite, component, S-Video, and RGBHV the RG59 will easily carry
the signal as far as you want it.

I would not consider using an aluminum braid shielded product for any base band style
signal. Also as a bonus these make excellent line level audio interconnects too where
the RG6 CATV cable will not. RG6 CCTV (bare copper center and bare copper braid) is
great for this application too. RG59 is not going anywhere anytime soon.

thylantyr
09-29-2006, 02:30 PM
Bill Lummus
09-05-04, 07:36 AM
I meant, some specific examples of cables- like manufacturer and part number.

Larry Fine
09-05-04, 08:34 AM
Sorry, I misunderstood. I'm not a part-number walking catalog like some people are,
but I could do a search.

http://www.cablestogo.com/product.asp?cat_id=304&sku=43054

http://www.partsexpress.com/pe/showdetl.cfm?&DID=7&Partnumber=100-250

http://cu1.com/rgplencopcoa.html

http://www.l-com.com/sdex/H16.JSP

http://www.electrocables.com/cpage06.htm

http://www.twacomm.com/Catalog/Model_5011.htm
:D


DominoGold
09-08-04, 07:24 PM
Well, to put the whole thing to rest I am doing 2 things...

1. Letting the company that does the low voltage do their "plasma package".
I have a sample of the wire they use for both standard coax runs as well as what
they are using for the component cables.

On the white wire it says:

DirectConnect RG6/U 3GHTZ TESTED 18 AWG 60% BRAID PVC COAX CABLE HDTV CL2(UL)
E230635 CSA 220255

It looks like copper in the center. I know this isn't ideal, but shouldn't it be
sufficient for component?

2. I am also running some component cables through the wall that I've used before
just in case this doesn't go as planned.

Bill Lummus
09-08-04, 07:29 PM
I'll reiterate- get some PVC pipe in the wall so you can replace the wires if
you need to. I also would use better shielding that that. For video cable I like
foil+>90% copper braid.

Johnla
09-08-04, 10:24 PM
Originally posted by DominoGold
It looks like copper in the center. I know this isn't ideal, but shouldn't
it be sufficient for component? Why is it not ideal? You do not need anything
"more" than copper!

DominoGold
09-09-04, 05:08 AM
I meant the RG6 cable that he uses may not be the "best choice"
(not referring specifically to the copper center), but shouldn't it be
sufficient for component?

Bill Lummus
09-09-04, 09:39 AM
Depends on you and your enviornment. I don't think it's adequately shielded and
I don't know what the dielectric is. It will certainly pass the signal, but may
compromise performance- particularly in a high RFI enviornment.

catapult
09-14-04, 06:34 PM
Just as a point of interest, video and digital audio are RF signals if you look at
the frequencies involved. Any good quality copper RG6 or RG59 should work fine for
a short run of either but you don't want to solder just any old RCA connector you
find at Radio Shack on the end. Analog audio is less demanding of both cables and
connectors.

Larry Fine
10-04-04, 07:45 PM
I will say once more that, for audio and video, RG-6 has NO advantage over RG-59.
As good, maybe, but not better. There are disadvangtages to RG-6: stiffness,
aluminum (shield) and/or steel (clad center), difficulty of finding suitable
connectors (other than F-to-RCA adapters).

WA2000
10-05-04, 07:05 AM
Thanks Lary, I'm probably obsessing too much about the cables. I did build
components out of RG6 (Belden 7710). They are quite stiff. Probably too stiff.
To the point where they could use a locking RCA.

Figgie
10-07-04, 08:48 AM
I build my own cables.

As with any other job. Having the proper tools is key :) I used 20 feet RG6 equivalent
cables (canare V5-5cfb) for video purpose with BNC ends. Overkills. Yes. But I
rather go over on video then get a fuzzy soft picture ;)

10-15-04, 03:46 PM
Originally posted by CJO
Howabout attenuation over several hundred (or thousand) feet? :)

For audio and video, and not RF, I'd say the same thing: I'd rather use an
all-copper RG-59 than a copper-clad-steel, aluminum-shielded RG-6. The copper
is more important than the extra thickness of the -6's dielectric.
However, a distance of hundreds of feet of coax is really a mis-application for
analog audio and baseband video. For these, you need a different method, such as
CAT-5, RF, etc.

tvtech1
10-15-04, 04:03 PM
However, a distance of hundreds of feet of coax is really a mis-application for
analog audio and baseband video. For these, you need a different method,
such as CAT-5, RF, etc.

The signals will travel much further over coax then any twisted pair scheme.
It's not 'untypical' to send analog video over 500 feet of cable, that's what DA's
are for.

CJO
10-15-04, 06:17 PM
Larry, I'm not sure where we are having the miscommunication, but you can purchase
RG6 with a solid copper center conductor.

lovebohn
10-15-04, 08:35 PM
I thought Belden 1694a is solid copper or better yet referred to as "BC" bare copper.

CJO
10-16-04, 10:04 AM
It is.

bpape
10-16-04, 10:35 AM
Belden 1694A is used all over the place for AV cabling. It is a fine choice for a
sub cable. For subwoofer usage, it will perform just as well (and better than some)
exotic cables costing far more. Put a good crimp style RCA connector on it and you'll
be fine. 1695A is slightly smaller but with Teflon Dielectric. Also over double the
price. As larry said, stay away from copper clad steel stuff. This is not at all
desirable for audio applications.

Larry Fine
10-16-04, 05:51 PM
Originally posted by tvtech1
The signals will travel much further over coax then any twisted pair scheme.
It's not 'untypical' to send analog video over 500 feet of cable, that's what DA's
are for. Even with good baluns? As Johnny Carson used to say: "I did not know that!"

I have used amplification to increase distance for AV, but I've never had to push it
that far. I've even used a low-power stereo amp with a voltage divider at the
destination receiver for audio.
Originally posted by CJO
Larry, I'm not sure where we are having the miscommunication, but you can purchase
RG6 with a solid copper center conductor. I understand, and you might even find that
inside a copper shield, but I still say that RG-59 will perform equally, if not better.
Plus, it's more flexible and easier to terminate.

My point is that, except for RF use, -6 has no advantage over -59. Maybe someone else
can explain more technically that I.


CJO
10-18-04, 09:09 AM
I'll agree with you that RG-59 is more flexible and (somewhat) easier to terminate,
but RG-6 is technically better than RG-59 for both baseband and RF use.
The only difference between the two is that the RG-6 has a larger (18 gauge as opposed
to 22 gauge) center conductor, which means that it has less attenuation over distance.
I.e., you can run the same signal for a longer distance with less loss using RG-6
instead of RG-59.


tvtech1
10-18-04, 01:15 PM
Even with good baluns?

There is no way a transformer (balun) can have a flat frequency response across the
video band, nor can it have no attenuation. Group delay will be a factor as well as
insertion loss. The only way to send quality video over a twisted pair is to use an
active device. An op-amp to create a differential video signal and match the cable
impedance is required.

/////////////////////////////////////////

RG6 vs. RG59 pic;
http://www.upgradefever.com/gallery/showphoto.php?photo=67&size=big

thylantyr
09-29-2006, 02:30 PM
How would you wire up a XLR to RCA cable for your xover???

Using Belden 8760 twisted pair.

RCA Output to XLR Input {Analog preamp out to Behringer XLR input}

XLR Pin 1 = Shield ground => connect to XLR pin 3
XLR Pin 2 = Positive balanced signal => one center conductor to RCA hot
XLR Pin 3 = Negative balanced signal {now ground} = one center conductor and drain wire to RCA gnd.


XLR Output to RCA with -6dB output gain {Behringer output to Adcom RCA input}

XLR Pin 1 = Shield ground =>one center conductor and drain wire to RCA gnd.
XLR Pin 2 = Positive balanced signal => one center conductor to RCA hot
XLR Pin 3 = Negative balanced signal {now ground} = don't connect

** I installed the switch so I can toggle between
-6dB and 'normal'.


XLR to XLR {Behringer output to QSC input}

XLR to XLR
XLR Pin 1 = Shield ground => drain wire
XLR Pin 2 = Positive balanced signal => one center conductor
XLR Pin 3 = Negative balanced signal = one center conductor

** I can't remember, but I don't think I made directional
cables for XLR to XLR. I hear no noise. I don't expect big
problems with short cable runs.

also is there one cable that's good for balanced and unbalanced usage...

All those cables {non coax} will work for analog audio,
balanced and un-balanced, unless you have to run hundreds of feet per cable then it's better to 'do the math'
and figure out the details.

The big difference is awg wire, cable thickness, foil or
braided shielding, and jacket material.

I'm probably going to use 8760 again mainly because
it fit the Dayton RCA's with Techflex and I like the beefy
18 awg wire for durability. It's nice to have a 0.222" cable
diameter vs. one that is 1/2 the size, gives the illusion of
uber cable due to it's size.

thylantyr
09-29-2006, 02:31 PM
I placed my order for Belden 8760 audio cable,
500' roll {$85}.

I also ordered Belden 1694A RG6 cable, 500' roll ($155}
to rewire my house and to make some SPDIF 'digital'
cables using Canare RCA's.

I snagged some Canare connectors {F, RCA} to try.

The big deal with coax is getting the crimpers and strippers to do a good job. Prices are extreme, cheap to
expensive. The crimpers have a special die for the size
cable you buy and dies are interchangable.

Partsexpress has a $15 tool and you can get the 'Paladin'
brand of die for $25. Paladin has two tools, the 1300 and
8000 series of crimper that cost ~$45 - $60. They also
have 'combo' deals where you can buy the crimper + die
under a different part number.

For Belden 1694A cable and F connectors, the Paladin 8011
is the combo and I found a place that has it for $60. I've seen other tools that are in the 'hundreds' of dollars range.

For crimping Canare coax RCA {RCAP-C53}, someone on
another forum recommended another Paladin die 2657, it
cost about $20.

For strippping the cable, I snagged the Canare TS100E,
$67.

http://www.markertek.com/SearchProduct.asp?item=TS100E&off=3&sort=prod

I'll keep you posted if the coax cable/tools work out.


// Markertek.com Parts list //
Belden BL-1694A-500 1694A CM Rated RG6 Digital Coaxial Cable 500Ft Black @ $155.95

[BL-8760-500] Belden 8760 2-Conductor Paired Microphone Cable 500 Foot @ $85.95

Canare TS100E 5-In-1 Multi Stripper @ $67.23/ea

[B-P-3] TecNec Premium BNC Male to RCA Male Flexible Video Cable 3Ft @ $6.39

Canare RCAP-C53 RCA Crimp Plug fits Belden 1694A or 9116 or 9066 @ $2.80/ea

Canare FP-C53 F Connector for Belden 1694A or RG-6 @ $2.10/ea

thylantyr
09-29-2006, 02:32 PM
* Update *

http://home.pacbell.net/lordpk/cables/

Pictures are numbered 1.jpg through xx.jpg to see
step by step progress.

I have a few directories.

Belden_8760_Cable
This is the analog cable I use with Dayton RCA and XLR.
Techflex is an option to make the cable pretty.

Belden_1694A_Crimp_RCA_Cable
The coax cable I used for my digital audio connection between the DVD player and Roland mixer. I will use this cable to rewire by cable TV as the picture quality isn't great.

Belden_1694A_Solder_RCA_Cable
I bought a while back some Dayton RCA that interfaced to
coax cable, solder type. I wasn't sure about how this would
work as I don't clearly see how to solder the braid. I did
some tests and figured that you really can't unless you
physically solder a wire to the braid to the metal RCA
chassis. But, I noticed that this Belden cable does fit snug
so it might work well. There is a set screw on the RCA
onnector that you loosen, insert cable, solder the center
pin, then screw the set screw tight to put pressure on the
braid to make good electrical contact. It's not bad and it
can cost less than buying crimping tools -- but the Canare
RCA's with crimping are actually rated for 75 ohm,
200mhz, I don't know if the Dayton are. This probably isn't
a really big deal for an average installation.

Canare_TS100_Coax_Stripper
Expensive, about $60-$70. If you only have to make one
cable you can do without and just be careful when you cut
the cable. You can use the ruler shown in the pics to get an
idea on how to make the cuts.

SPDIF_AES_Transformer
Not DIY: RCA to BNC to mate with the transformer.

thylantyr
09-29-2006, 02:33 PM
Last post. I wrote this article as I was seeking cables last year. If you find
any issues, post them and we can fix the article.