Reliability for gigging keyboardists

Introduction

This blog post is about reliability of equipment and is intended for gigging musicians, keyboard players in particular. It gives a rather formal insight in reliability, together with down to earth practical hints and tips to improve the reliability of your setup. I wrote this article because on Facebook and fora all over the web I found a lot of mispercentions on reliability and ended up in futile discussions. I’m a design engineer in railway vehicle electronics and I’m educated in (among others) reliability studies.

Definition

Reliability can be defined as “the probability of a system to perform as designed at any given moment”. The opposite is the probability of a system not to perform as designed. In fact this means that a system is unreliable when you want to play (for example) a C-major chord with a piano sound at mf loudness, and the output is not C-major, not a piano, not mezzo-forte, or simply not the desired sound quality.

Sometimes reliability is called dependability, how much you can depend on a system. Some languages have words for reliability that relate to trust. How much a system can be trusted. These a good equivalents. The trust you put in your rig is heavily related to the reliability of it.

A keyboard setup with all of its components is called the ‘system’. The system boundries are vague. For the article I take the power outlet in which you plug your own cable as the outer boundary of the system, just as the audio outputs of your stage mixer, DI or keyboard. You as the musician who pushes the keys and buttons are also outside the system.

The chain

A setup has many components. Most components play a role in the creation of the output of the system. The most simple of setups is where you have a single synthesizer, on one end connected to the wall outlet, and on the other end connected to the PA systems.

In this case, if the power cord, the synthesizer, or the audio cable fail, your system will be unavailable. The total reliability is determined by the reliability of each of the components. Mathematically this can be described as follows:

If the reliability is the percentage of time / usage that the component is performing as designed, than the total reliability of the system is the multiplication of the individual reliability of each component.

In other words: if the cord, the synth and the audio cable each work correctly 9 out of 10 times, the chances the whole setup will work correctly are 0.9 × 0.9 × 0.9 = 72.9%. Three out of ten times your setup wil not work as you hope it would…

The more complex a setup gets, the more factors influence the reliability. A more realistic setup:

Complexity makes less reliable

With two synthesizers, a rack mixed, a DI and a power distributor, any given sound will required four boxes and five cables to work. You can easily imagine that the reliability of each component has to be high when the availability of the system output (a.k.a. your music) has to be high. With the same per-item availability, the total availability of a single keyboard in the rig would be 0.99 ≈ 39%. You better make sure each item performs way better than 90% of the time! And even if every part works 99 out of a 100 times, around 1 in 10 times some part of your rig will fail.

Redundancy

The above diagram provides another nice insight. The second synth could perform well even if the first one fails. This is called ‘redundancy’. One component can take over the function of another component in case of a failure. Since both synths are wired up at the same time, this is called a ‘warm standby’. You just have to press the keys of the other synth to get it to work. A ‘cold standby’ would be when you have a spare synth waiting in the dressing room. Redundancy would be complete if synth 1 and synth 2 are of the same type and loaded with the same sounds. When this is not the case, the redundancy brings you to a degraded mode, where some capabilities are lost. Maybe you lose some sound quality, or some specific samples, but overall you will manage to play the gig to the end and people are satisfied with your performance.

Single fault failures

Another thing to notice in the diagram is that some components don’t have a fall back, a spare. If the power distributor failes, or the rack mixer, or the DI, or any of the audio cables, you will lose the ability to perform. This single faults that lead to a failure to deliver output are the most vicious ones that you have to take into account.

Common source of failures

Not easily identified in the diagram, but not hard to imagine, are external sources of failures that render your whole setup useless or defect. When the power outlet has no power, or produces violent surges that destroy your equipment, or when rain starts to pour and you are unprotected on an open field, all equipment is exposed to the same source of potential failure and may be influenced by it.

Another common source of failures could be handling prior to the gig. If all your equipment is carried in the same van, and the van gets caught in an accident, all your equipment may get damaged or completely lost.

Protection against failures

Get reliable equipment

The single most valuable tip I can give is to buy reliable equipment. All other advices are useless if your don’t start off with reliable components in the first place. Sure that 60’s Mellotron sounds nice, and that chopped down Hammond B3 from 1936 is the best there is, but from a standpoint of reliability, those beasts aren’t top notch. And that goes for every single component in the line from left to right in the diagram. Your power distributor should be just as reliable as your DI box.

If a part ever fails on you, try to find out what caused the defect, take the cause away and test to see if you can reproduce the failure again.

Gigging with unreliable equipment is no fun. At least: I don’t like to play with sweaty hands. If there is a 50:50 chance I don’t get the desired sound when I strike a key, I’d rather not strike that key at all.

Keep it simple

You should fully understand how your rig works. Skip unnecessary equipment and try to keep the route from power outlet to PA as short and simple as possible. Yes, that one vintage tape echo sounds great, but when it is in your single output line to the PA, your whole system availability depends on this box.

Simplicity is also in cabling. Try to avoid cable spaghetti, don’t use conversion connectors, don’t use extenders, and make sure you have everything hooked up without errors. Poka yoke is the Japanese word for mistake proofing. Colour coding your connectors, blanking out unused ports on your equipment, prefabricated cable looms and extensive labeling all help in preventing mistakes. On some equipment you can just take of the knobs you don’t need to touch (for example on DI’s). That may save you time debugging the rig when one channel fails to play.

Apply preventive maintenance

Don’t apply percussive maintenance but instead take care of your batteries, replace damaged cables and clean your equipment every now and then. Fan’s, connectors, faders all collect dust. When connectors (in particular Jack) are not used for some time, they will degrade. Take the plugs out of your rack mounted equipment and use some compressed air to clean out all the slots and holes in the equipment!

Keep away from contact cleaners with parafine on electrical contacts though. They do work for mechanical switches, but not on those rubber contacts in your keybed. The lubrication provided by the parafine will collect the dust right where you don’t want it. And WD-40? Or brake cleaner? No, no… just don’t.

Get spares

TIP: label your identical spares so you can figure out which one failed at some point. You need to identify you defects after a gig. It is quite easy to remember that speaker A failed, but it is hard to remember that the-one-speaker-with-that-scratch-on-the-back failed.

If you have standardized all your equipment to use the same power supply cords, audio cables, control cables and such, it is easy to keep some spares with you for each cable. External power supplies with different voltage ratings, barrel plugs or polarization are your worst nightmare. Be sure to identify the differences and label your PS’es clearly. No one wants to read those small black letters on the back of the wall wart adapter on a poorly lit stage while your singer is shouting at you that ‘we should have started minutes ago’!

Spare cables should be of appropriate length. Better to keep a couple of 3m spare TRS cables close. That will probably work you through the gig with all your cables, although they may be too long.

Prepare for a plan B, and C

Build up your rig at home and with every component you connect ask yourself the question: ‘what if this fails?’. Plan B could be to take a spare, but also to take another synth, skip a mixer, play without that particular effect unit, or… Milions of solutions may come up in your mind. Pick the most reasonable one and try it out. Skipping an effect unit may work, but do you have all the cables to work around it? And when you don’t use the mixing desk, how are your sound levels matched? Write down plan A and plan B if you like.

Plan B could also be playing mono instead of stereo. Be prepared what to do when this happens. This could also come in handy when the venue has a monaural PA system or the front of house technician runs out of inputs on the desk. Degraded modes like mono playing are sometimes the solution to problems that lie beyond your area of influence.

Plan C could be using a USB midi controller and a synth app on your phone or tablet. Some “bread and butter” sounds could help you make it through the night. Certainly not ideal, but a band without keyboards altogether would probably be even more disastrous. Don’t forget your charger and cable!

Test, test, test!

Cable tester

Get a multimeter or a dedicated cable tester and test your cables. Also when you run into problems and suspect a cable to be to source of the trouble, test it when you take it out. This will make sure that you identify the problem, and not accidentally ‘resolve’ the issue by touching your spaghetti.

Do regular checks of your cables, every year or so.

Software testing

We have all been there: after the last rehearsal you update your synth’s OS and during your performance you notice that your patches sound odd, or your volume pedal ceased working.

After any upgrade, update or change, make sure to test with all auxilliary equipment in place, and all of your patches. Especially the ones with odd configurations (use of that vector joystick, ribbon, vocoder, individual outputs with click tracks) are to be tested thoroughly.

Treat your equipment well

Flight case

Don’t use a cardboard box or a blanket and a bike’s inner tire (yes, I saw someone do that) to protect your valuable instrument during transportation. A decent flight case will provide the best possible protection. Make sure it fits. Fill the gaps with foam (and not with your sustain pedal). Don’t throw your case (not with, and not without the keyboard in it) and carry rather that using the wheels on concrete slabs.

Cases protect against impact, shocks and vibration, but there is only so much a case can protect against. In many respects your equipment is more vulnerable than your body. Imagine what you would look like if you were in the back of a truck lying between those other cases without protection.

Dust cover

Dust is among the worst enimies of electronic and mechanic equipment. It builds up gradually, making moving parts get stuck, knobs crackling, electric circuits flash over and cooling less effective. Someday dust will cause your equipment to fail. Cleaning will help extending the period of trouble free operation, but preventing the ingress of dust altogether is the best option. Cover your equipment with a dust cover, and also cover all those open slots in your rack.

The cover will not only work for dust, but may also prevent that drop of rain, or that glass of wine from damaging your instrument.

Direct sunlight

Keep your stuff out of direct sunlight or other heat sources. Noticed how many keyboards are in a black case? And how hot it gets when a black surface is exposed to direct sunlight? No wonder that fan in your Kronos can’t keep up.

Heat is the main contributor to deterioration of electronic equipment. (see The Arrhenius equation) At some point the equipment stops working, or will show random failures. At best the equipment will grow old early. Cooler electronics last longer.

Power supply conditioning

As stated before, external power can damage your equipment. Some form of conditioning of the power could prevent accidents from happening. Your choices vary from doing nothing at all, to a surge protector, to a continuous conversion UPS.

Protection against indirect lightning strikes (the surges or voltage peaks that are induced in the power supply circuits and usually destroy your equipment) is provided by surge protectors. Don’t believe half of the claims on the marketing brochures: surge protection may be adequate in some situations, but may not nearly enough in others. It’s all a matter of chance (some call it luck).

All your equipment already has some form of surge protection. Multiple protectors in parallel may ‘help’ one another absorbing the energy of the surge, but the first surge arrester to ‘fire’ will most likely absorb the majority of the energy. And most arresters are poorly documented, so you can hardly configure the best combinations for your setup.

A UPS (uninterruptable power supply) may shape the voltage from the net. More expensive (and heavy, and ironically less reliable) UPS’s provide a pure sine wave at exactly the correct voltage and frequency. Line Interactive UPS’s kick in only when voltage is dropping below a certain point. Even cheaper UPS’s only provide power for some time when the power is completely lost. Whatever type you choose, device selection is mostly determined by what you want to spend, how much power you need and what weight you are willing to carry. Don’t think a UPS will make you able to play during a power outage. The PA will most likely not work either. But when power comes back on, you are probably good to go without a 3 minute reboot cycle, or worse: data loss because of the sudden shutdown.

Cables and cable management

As can be seen above, your cables determine for the greater part the reliability of the whole setup. Although cables are relatively cheap and spares are easy to carry, a crackling cable is very annoying. Good quality cables (I use C128, C301 or TSK1042 cable from Tasker with Neutrik plugs) will survive longer. Don’t run cables over the floor where you (or worse: your female band member with high heels) walk over it. And roll them up carefully: your elbow is not for wrapping the cable around.

Power supply cables are a different breed. Where I live (The Netherlands) we have have standardized our wall outlets to great extend. Almost all are of the “Schuko” type, 16A 230V 50Hz. The Schuko standard has no fuses in the cable, nor in the outlet (unlike what is custom in for example the UK). This means I have a bunch of cables from Schuko to IEC 60320 C13 and I use them for all my equipment (except for the Roland D50 that has a C9) and don’t keep track of what to use where. I have short cables, long cables, straight and right angled connectors on any of the ends.

For any cable (even the small iPad cables) I use a cable wrap to keep them together. This works during transport and to wrap everything to the keyboard stand or bundled together on the floor board. This helps preserving them, making them more reliable over time. Cables are best kept in a case or in the side pockets of your bags. Don’t put your spares in the same case though!

Geef een reactie

Het e-mailadres wordt niet gepubliceerd. Vereiste velden zijn gemarkeerd met *

Ben jij een spambot? *