DIY Instrument Lead Mini-Tutorial

[DrNomis_44]

Hi Everyone,

Since I'm making some XLR to XLR leads for a good mate of mine and I'm going to be doing some repair work on some of my own leads today, I thought that it would be a good excuse for me to do a mini-tutorial thread about making your own DIY instrument leads, and show you how I go about making them.

I'm going to be documenting the process with some pics as well as a write up.

To start the ball rolling, here's a quick re-cap of the four steps for preparing the leads prior to soldering the plugs onto them, they are:


1, Cut.....Cut the cable to the required length.

2, Strip...Strip the plastic insulation off the cable and the inner-conductors.

3, Twist...Twist the individual strands of shielding braid together so that it forms one neat bundle, do the same for the strands of the inner conductors.

And finally....

4, Tin.....Tin the neat bundles of strands by coating them with solder, they should look shiny once you're done.


I will be going into each step in more detail and adding pics soon so stay tuned....

[JohnH]

Good idea for a thread Doc, I reckon there’s more than a few people on the forum who’d be interested to try this.

[Marcel]

Many prefer to 'tin' the lead ends before taking them to the plug/socket to be soldered on to the pins. This does make the actual soldering a lot easier and often makes for a more reliable solder joint.

For myself I prefer to fit the wire into its intended final location on the pin first, and then apply/use solder to secure the joint. On a TRS or TS plug this allows me to put the wire neatly through the tiny hole to give added mechanical strength to the final joint, and on a XLR allows me to ensure the wire is fully inside the cup at the end of the pin before solder is applied. Down side is if the wire is at all dirty or has any corrosion there is limited scope to correct any 'wetting' issues should they arise, and often may require a full clean and start from the beginning again to rectify those issues.

[DrNomis_44]

Yep, there's lots of ways to do it, if I'm making up an XLR-XLR lead, or a TS-TS, or TRS-TRS lead, I like to tin the wire and connections separately and then let the solder do all the work for me when I go to solder the connections together, definitely insures a good reliable joint, I'm just going to have something to eat first before continuing on with the mini-tutorial.


When you're doing the actual soldering, there's three rules to observe in order to get a good solder-joint, they are:


1, Cleanliness.

2, Cleanliness.

and....

3, Cleanliness.


Expanding on that....you want to make sure that the tip of your soldering-iron is clean and shiny, if you're working with a soldering-iron that has a dirty, and, or, rusty tip, you're not going to get joints which are shiny and have wetted the two surfaces to be soldered together, you also want to make sure that the surfaces being soldered together are clean and shiny, trying to solder to a dirty surface will not produce a good and reliable solder joint.

[Mark Gill]

how do you keep it clean, DrNomis..?

[DrNomis_44]

how do you keep it clean, DrNomis..?

If you're trying to solder a piece of wire to something and it looks a bit dull, you can use some fine grit sandpaper to get it shiny again, you can also use sandpaper to gently clean the tip of the soldering iron but first make sure the soldering iron is switched off, once the tip is clean and shiny, switch the iron back on again, let it heat up to temperature, then apply some solder to the tip, and then wipe the tip on a damp rag or the cleaning sponge provided with the iron.


If you're trying to solder wires onto the solder lugs of a plug, and the solder doesn't want to take to them, you can try sanding the solder lugs a bit with some sandpaper, or, you can use a small needle-file or a Stanley-knife blade, sometimes the plating on the solder lugs of a plug can be a bit iffy, sanding, or scraping the solder lugs till they're shiny can fix it so that the solder more readily takes to the solder lugs.


I tend to make most of my DIY Instrument leads about 5 metres long, although I have made a couple of 10 metre ones in the past, I think 5 metres is about optimum, but there's nothing stopping you from making them longer than that, although you do start running into loss of high-end issues with longer lead-runs, that's one of the reasons why balanced XLR leads started being used in live gigging situations, the balanced XLR leads also reduce a lot of the hum-pickup that can occur with un-balanced instrument leads.

[Simon Barden]

I tend to make most of my DIY Instrument leads about 5 metres long, although I have made a couple of 10 metre ones in the past, I think 5 metres is about optimum, but there's nothing stopping you from making them longer than that, although you do start running into loss of high-end issues with longer lead-runs, that's one of the reasons why balanced XLR leads started being used in live gigging situations, the balanced XLR leads also reduce a lot of the hum-pickup that can occur with un-balanced instrument leads.

You are mixing up some very different issues there, Doc.

XLR (or TRS) balanced leads have a similar capacitance level to unbalanced guitar leads - often a bit more - as they are all made of very similar materials and the extra core and insulation increases the capacitance.

In the case of guitars and basses with passive pickups and tone controls, it's the high impedance of the instrument output that makes the effect of the cable capacitance more prominent, as the capacitance forms a low pass filter network along with the output impedance that has a lower and lower cut-off frequency the more capacitance there is i.e. the longer the cable, the more high frequency loss there will be.

This can partly be countered by using cable with extra low capacitance per unit length for longer runs. Some of these cables have half the capacitance per unit length of standard cables, so a 10m long low-capacitance cable will sound similar to a 5m long standard cable in terms of HF loss. A lot of guitars can sound over-bright if you use the very low capacitance cable for short leads, especially when going straight from the guitar into an amp. Of course this may benefit some guitars, whilst on others they may just sound a bit harsh. So it can be used as a creative 'effect'. You just need to understand what's going on.

Pedalboards and cables need a mention, especially if you have a board filled with 'true bypass' pedals. In this instance, with all the pedals in bypass mode, whilst no pedal will affect the guitars tone per se, the guitar cable is now the length of the cable from the guitar to the board, the length of all the patch leads, plus the cable from the board to the amp, which if those lengths are long, is going to affect the straight guitar sound considerably.

Which is why it's a good idea to have at least one 'always buffered' pedal in the chain. A good buffer should be transparent (though not all pedals have good transparent buffers - especially some of the older ones). The audio bandwidth of standard op-amp circuits is way higher than our hearing ability, so you should only be able to hear the effect of a good buffer in a good way. It will provide a high input impedance (normally 1 Meg ohm) for the guitar to 'see', which keeps the guitar's tone normal, and will provide a low output impedance for the signal to the amp (or other pedals) which will remove most of the capacitive effect of the output cable to the amp as the low pass frequency of the cable 'filter' is now above the normal audio bandwidth. So a buffered pedal can drive a far longer output cable than you can get away with with all true-bypass pedals on your board.

For a buffered pedal design, look no further than Boss, as their pedals all have buffers and and have no 'true bypass' switching. Alternatively it's now fairly common for people to have an 'always on' booster pedal like the Xotic EP Booster or TC Spark at or near the start of the FX chain, set for maybe a very slight signal boost. This can both add a 'nice' small EQ tweak to the sound and also act as a signal buffer.

You'll have noticed that most guitars and basses don't have balanced XLR output connections on them (though some with internal pre-amps do and the Les Paul 'Recording' style guitars had transformer balanced low impedance outputs, designed to be plugged directly into a mixing desk). Balanced outputs are generally the province of 'pro audio' equipment i.e. the kit (apart from instruments) that you were once only likely to find in a recording studio or in stage PA equipment (but can now be found in home-studios).

Balanced audio connections are normally more than just 'balanced' (which refers to balanced impedance along the two signal lines and equal impedance to ground), they also operate using opposite polarity signals for better noise rejection.

A guitar lead is an 'unbalanced' connection, not because it uses two wires, but mainly because the shield is directly connected to ground, whilst the signal input has around a 1meg ohm resistance path to ground. There will be a slight connection impedance mismatch because the signal cable impedance will be different to that of the braided outer 'shield' cable.

[DrNomis_44]

Rightio, before we start making some DIY instrument leads, we need to get together the raw materials, soldering iron, or soldering station, solder, and some tools, and then set everything up on a convenient workspace.


Materials:

Cable, Jaycar Electronics sell two different types of cable that I have used to make instrument leads, one type has a single core and shield surrounding it, the Jaycar Electronics catalogue number is WB-1508, it is roughly 6.5mm in diameter and has a black outer plastic-sheathing, the other type has two inner cores surrounded by a shield, the Jaycar Electronics catalogue number is WB-1530 has a black outer plastic shrouding too, I mostly tend to use the WB-1530 cable, here's a comparison pic to show what they look like, the top one is the WB-1508 cable:




Plugs, there's two types of plugs I tend to use when I make my DIY instrument cables, there's a metal right-angle plug, and a straight one, here's a pic so you can see what they look like:




Both are stocked by Jaycar Electronics and I've found them to be pretty reliable.

https://www.jaycar.com.au/6-5mm-pro-...-plug/p/PP0157

https://www.jaycar.com.au/6-5mm-pro-...-plug/p/PP0159

[Simon Barden]

I expand any too-small holes in order to get the wire through them. I really don't like just using solder to fix wire to metal, though sometimes, like with pots, there's no other choice.

When I started off soldering I was told that a good mechanical connection males for a good solder joint, and I've stuck to that wherever possible; putting the wire through any holes then wrapping the wire back and around so that it can stand at least a gentle tug on its own before applying the solder.

Sometimes I find it easiest to strip more of the wire than necessary just so I can tin just the very tip, then if it's a bit wide, cut the end down a bit with wire cutters so that it's easy to fit through the hole without some strands failing to pass through and producing messy whiskers. Then do the wrapping part and cut off any excess wire (including the tinned tip).

[corsair]

When I started off soldering I was told that a good mechanical connection males for a good solder joint, and I've stuck to that wherever possible; putting the wire through any holes then wrapping the wire back and around so that it can stand at least a gentle tug on its own before applying the solder.

See, the TV repairman who taught me to solder was of the opinion that a good soldered join didn't need a mechanical join to be strong; as long as there wasn't too much tension on the soldered joins... like the tension in an instrument cable! I mean, we've all tried pulling a soldered join to bits, haven't we? They're pretty damn strong mechanically as well as electrically!
I've always just soldered onto whatever tags/cups/ears that were and have never had a mechanical failure that I haven't caused by treading on the cable, which is going to cause a problem regardless of the type of soldered join employed!

Of course, YMMV....