Revolutions Per Minute

How Not To Fix Things (Especially Things That Turn)

Issue 114

There are few things more frustrating than having trusted an expert to fix something, only to have it returned more broken than it was to begin with! The wrong choice of “expert” will often result in a small defect which would have been relatively simple and inexpensive to repair, escalating into major damage, requiring much more extensive and expensive measures to put right.

This situation can be encountered with all manner of things, from audio equipment to household appliances, from cars to industrial machinery, from an alarm clock to a highway bridge! While some sectors are strictly regulated due to their critical nature, audio is usually regarded as a low-risk field, since nobody will die if the turntable has speed instability or if the amplifier is distorting.

Throughout my life, I have seen a lot of bad repair jobs, often in critical applications. As an example, a few years ago, I took our car to the garage to have some simple routine maintenance done on the brakes, by a mechanic who had proven knowledgeable and reliable – prior to the 2008 economic crisis. I drove the 40-mile trip back home safely, but while parking on my driveway, the brake pedal went all the way to the floor. Goodbye brakes!

Upon inspection, I saw that the mechanic had incorrectly (and outright stupidly) routed a brand new flexible brake hose around the suspension in a way that it would get squeezed between the car frame and a suspension member on each bump, pothole, etc. Luckily, it only broke on my driveway and there had been no emergency braking required on the way home.

As an engineer, formerly also having worked professionally with motor vehicles but doing much more complicated work nowadays, I do not find this difficult to fix on my own, properly and safely. However, as the day only has 24 hours, I cannot work full-time in the audio industry, fix my own car, build my own house, do my own plumbing, do my own electrical work, be my own gardener, cook healthy meals for the family, homeschool the children, manage my retirement investments, be my own accountant, fix the washing machine, fix the kettle, fix the camera, grow my own food, be my own doctor, and be proficient in all of these at the same time!

Inevitably, we all need others we can trust with doing their job properly, so we can focus on ours. Sadly, stories of bad plumbing, dangerous car repairs, and even fake doctors who never actually studied medicine are all around us.

Finding myself stranded with no brakes, 40 miles from the garage, with no intention of actually ever going back to the same mechanic as all trust was now lost, and needing to find a solution without wasting further time on what had started as a very simple issue, I lifted the car up on sturdy axle stands (I still had them around) and fixed it myself (I even had a new brake hose on the parts shelf), taking time away from what I should have been doing, if the mechanic would have done his job properly. Since then, I have gone back to doing all the car maintenance myself, as I am afraid that it may take much longer if I try to trust someone else with it, ending up with me having to undo what was badly done and redo it properly. But I really do wish there would be someone I could genuinely trust, nearby. Of course, I have met good car mechanics in my life, but they are all too far away from where we are currently living.

One can only hope that those tasked with working on airliners, nuclear reactors and medical equipment are proving more reliable.

While most failed audio and musical instrument repairs I have come across are indeed not as life-threatening, a few weeks ago I came across the world’s worst repair job and the most dangerous attempted audio repair I have ever come across.

It could perhaps even be considered a murder attempt!

I guess many of you will have encountered hi-fi equipment that is not performing as it should, and still doesn’t even after a trip to the repair shop and half a month’s pay relieved from your wallet. It gets a bit worse with studio equipment, but it is especially bad when it comes to musical instruments. So, I received this call from a friend who had bought a “restored vintage synthesizer,” which he initially described as, “I think there might be something wrong with it.” When it arrived in my lab, it was obvious that it had been badly bodged by someone clearly not qualified to carry out this type of work.

Never use a fuse of the wrong rating!

The two-prong power socket that had been fitted was unsuitable for equipment requiring an electrical ground and the chassis had been badly butchered in the process. The fuse installed was a 3.15 amp fuse, instead of the 315 mA indicated! My friend then added the best part: “I got a bit of a shock when I touched it!”

WARNING: The following picture may cause severe discomfort to sensitive, technically minded individuals.

Notice the three bare wire ends twisted together (to the right of the twisted-pair red wiring) with no soldering.

Opening up the power supply, we found some bare wires loosely twisted together, not even soldered. The fuse had been entirely disconnected (the round black housing with no wiring connected to it)! In European electrical color-coding, brown is the live wire, blue is neutral and the green/yellow wire is ground.

So, not only was an incorrect two-prong socket fitted, but the chassis ground had been twisted together with the live wire, essentially hard-wiring the 230-volt AC line to all of the exposed metallic parts of the instrument, and with no fuse in the circuit! According to the electrical codes in most European countries, the electrical outlets in the wall can deliver 16 amps, 13 amps or 10 amps of current at 230 Volts AC. And the only thing limiting the current flow would be the resistance of the body of the keyboardist! To put this in perspective, any current exceeding 0.03 amps is already considered potentially lethal.

The frame of the instrument was wooden, insulating the exposed metallic chassis at the top from the building’s ground.

The problem would not become noticed until somebody touched the chassis, which could then very well be the last thing they ever get to touch.

In theory, the electrical codes usually also call for an RCD (Residual Current Device) to be fitted to all electrical installations, to protect against such incidents by limiting such fault currents to 30 mA. So, why did the RCD not trip at my friend’s band’s practice space when he felt the shock?

Was he just lucky and the current just happened to be less than 30 mA because he simply did not make good enough contact with the chassis? Or was the RCD inoperative (or even entirely missing)? Perhaps another job badly done?

If the simple task of connecting three (already color-coded) wires properly is proving challenging in today’s times, then what is there to say of the challenges of maintaining a car’s braking system, the control rod system of a nuclear reactor, or the turbines of a passenger aircraft?

Considering that the dimensional tolerances and adjustment accuracy required for turntables, disk recording lathes and tape machines are at least an order of magnitude tighter than anything found in an automotive engine, it becomes clear that high-quality audio equipment, especially equipment with moving parts, must never be trusted to just anyone pretending to be a service engineer. It is all too easy and cheap to buy a soldering iron and pose as a “qualified audio tech.” But it really takes a lot more than that to be able to properly work on audio equipment.

Don’t be tempted by low prices for repair or calibration work. It takes a substantial investment in education and in quality tools to be able to do this kind of job properly, which will have to be reflected in the cost of the work. If the original manufacturer is still in business, this is the best starting point for getting an audio component repaired. For vintage audio equipment, there are very few people left in the world who can really claim to be adequately qualified. Seek them out and be prepared to pay them accordingly.

Supply tends to be regulated by demand. When more and more people demand cheaper and cheaper products, or cheaper repairs, more and more underqualified people will rush to “electrify” you, eager to cover the demand. At the same time, properly-qualified people may not be able to wait it out until everyone is done trying out if the services they provide can be had cheaper, so quality work and “a job well done” are increasingly at risk of becoming extinct.

As more and more people join the low-cost-everything sector, because of being paid less wages, they won’t be able to spend as much themselves. Eventually, there will be no market left for anything of decent quality, because nobody will be able to afford it, since everyone will be busy offering some sort of lower-cost product/service to attract a market share in an ever more price-conscious world. Who would be motivated to seek higher qualifications when they themselves have been rendered unmarketable?

This is exactly how American vacuum tube manufacturing collapsed, when cheaper but much lower-quality products flooded the market!

It doesn’t take much for things to escalate to the point where playing keyboards would be considered a high-risk activity! I keep on being reminded of the wise words of Peter Copeland, in his book, The Manual of Analogue Sound Restoration Techniques, about “the cost of everything and the value of nothing.”

It is up to all of us to keep the remaining highly skilled technicians, mechanics and engineers in business and see their skills passed on to the next generation.

(Note: “The Manual of Analogue Sound Restoration Techniques” is available for download from the British Library.)

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