DIY Instrument Lead Mini-Tutorial

[DrNomis_44]

Ah....sorry about that oversight, I blame that on me not having fully woken up due to insufficient coffee in me.

[Simon Barden]

It's easy to overlook as you already know how and it isn't hard - but for a comprehensive guide it needs to be there.

[DrNomis_44]

(Addendum):

To strip the insulation off the Jaycar WB-1530 cable I'm using to make the new DIY Instrument lead, I measured roughly about 20mm from the end and used the thumbnail on my left-hand thumb to put a slight nick in the insulation, after doing that I bent the cable back on itself where the nick was and then used a craft knife to carefully cut through black plastic sheathing of the cable, making sure not to nick any of the strands of the braiding, bending the cable back on itself helps to avoid nicking the braid underneath the outer sheathing.

Here's what the cable looked like after making a nick in the outer-sheathing with my thumbnail:



Here's what the cable looked like after bending it back on itself where the thumbnail nick was placed:



While holding the cable bent back on itself in my fingers, I used the craft knife to cut through the outer-sheathing of the cable, exposing the braid underneath it, while at the same time being very careful not to nick any of the strands of wire in the braiding:




After making the cut in the outer-sheathing with the craft knife, I proceeded to continue cutting the sheathing all around the circumference of the cable till I got back to where I had started from, this enabled the excess sheathing to be easily pulled off the end, exposing the braiding underneath:

[DrNomis_44]

It's easy to overlook as you already know how and it isn't hard - but for a comprehensive guide it needs to be there.

Sorted....

[DrNomis_44]

And as a bonus, here's how to test your newly-made DIY Instrument lead with a Digital Multimeter to ensure that it is a good one, note that I'm using a short blue pedal patch-lead for demonstration purposes, if your new DIY Instrument lead passes all of the following tests, then you have a good working lead:


First of all, set your Digital Multimeter to either a low ohms (say 200 Ohms) range setting, or, if your Digital Multimeter has one, the Diode/Continuity Test setting (I've shown it set it to Diode/Continuity Test):



For the first Continuity Test, touch the tip of one multimeter probe to the sleeve of one plug and the tip of the other probe to the sleeve of the other plug as shown in the pic, if you get a low reading and an audible beeping sound, then your lead has passed the first test:




For the second Continuity Test, touch the tip of one of the multimeter probes to the tip of one plug and touch the tip of the other probe to the tip of the other plug as per the pic, if you get a low reading and an audible beeping sound, then your lead has passed the second test:



For the third Continuity Test, touch the tip of one of the multimeter probes to the tip of one plug and touch the tip of the other probe to the sleeve of the other plug as per the pic, if you get a high reading and no audible beeping sound, your lead has passed the third test:




If your lead has passed all three tests then it indicates that you are getting continuity where you should be getting it, from one sleeve to the other, and from one tip to the other, therefore you have a good lead and it is ready for use, if you get different results with any of the above tests then that means something is wrong and it needs fixing.



You can also use an Analog Multimeter to do the three continuity tests on your newly-made DIY Instrument leads, on an Analog Multimeter continuity is indicated by the meter needle moving and then stopping over the zero mark on the meter-scale when set to a low-ohms setting, no continuity is indicated by no needle movement.

[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.

[Rabbitz]

Arrrrgh, I hate cleaning the soldering iron tip with "a damp cloth" or "a damp sponge".

It's messy, smelly and can damage plated tips with the sudden cooling.

Get yourself down to the supermarket and get hold of one of the gold coloured or stainless steel pot scourers. The ones that look like spirals all balled up. (see here - https://www.woolworths.com.au/shop/p...-steel-scourer ). That one pack for 89 cents will be a life-time supply.

Bin your damp sponge, place the scourer next to your solder station, when the iron is up to heat, plunge the tip in and out of the scourer once and hey presto, all sparkly clean.

[Marcel]

Arrrrgh, I hate cleaning the soldering iron tip with "a damp cloth" or "a damp sponge".

It's messy, smelly and can damage plated tips with the sudden cooling.

Get yourself down to the supermarket and get hold of one of the gold coloured or stainless steel pot scourers. The ones that look like spirals all balled up. (see here - https://www.woolworths.com.au/shop/p...-steel-scourer ). That one pack for 89 cents will be a life-time supply.

Bin your damp sponge, place the scourer next to your solder station, when the iron is up to heat, plunge the tip in and out of the scourer once and hey presto, all sparkly clean.

Must be the iron & damp sponge technique.... I have irons that have tips that are +20yo and one that is almost 40yo and I've only ever used the supplied sponges slightly damped with water ...

Only reason the sponge or scourer is there is wipe away any excess solder.... not for deep scrubbing away any burnt or burning flux...

[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.