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When the Chips Are Down


I have always been a hands-on technician, but two recent events provided a refresher course in the challenges facing large-scale operations. As an employer for the first time in 11 years, I am reminded of needing to be organized, thinking ahead (order service manuals and parts), anticipating problems (odd failures rather than typical ones) and having spare assemblies. Finding good help is not easy. Assuming minimal turnover, training workers is an optimistic investment, with the payoff being greater productivity.

Finding replacement pots for particular pieces of gear—such as the concentric depth/
frequency control on this Lexicon Prime Time—can be tricky.

Eleven years ago, technology was advancing faster than my employees’ skills, so I downsized the company and went solo. This new “freedom” to take chances allowed new opportunities in video, one being a vacation relief gig that turned into a full-time job.

Video forced me to think way outside the box. That technology’s complexity — integrating hardware and software, networking, data compression and the Internet — foreshadowed audio’s future, as hardware was simply too complex to repair in-house at the component level. It was the beginning of my transition to the “systems” level of maintenance, something my video friends jokingly referred to as Mail-Order Maintenance, or MOM for short.

MOM still requires troubleshooting skills, but only down to the equipment, interface or the subsystem (circuit board) level. Back then, we had spare boards to swap and overnight shipping. Now we can go to almost any consumer electronics/office supply store and grab a hard drive, media burner, monitor, cable or even a motherboard.

In this respect, computers have standardized the most common spare parts required for a multimedia facility, but they have also contributed to component availability shrinkage — let’s call that CAS. Here in audio land, we have one foot in the future and the other in the past. And while vacuum tubes and, more recently, audio recording tape have been reborn as boutique products, other components are joining the endangered species list.

Computers and related compact, ultra-miniaturized products (like cell phones) are possible thanks to surface-mount technology (SMT), which is driving the electronic component manufacturers away from making stuff with “legs.” (The wires that dangled from traditional transistors, capacitors, etc., are known as “leads.”) And so, in the interest of cramming as many components in the least amount of real estate, axial-style capacitors, for example, are being dropped in favor of the radial package and audio-grade transistors are becoming harder to find.

Axial capacitors have one lead out each end, while radial
capacitors have both leads exiting the bottom.

No discussion of MOM is complete without addressing shipping issues. No matter what your preferred carrier, it’s important to pack defensively to minimize damage potential. The most obvious is physical damage to the face plate (bending around the rack ears), but hidden damage to PCBs is bad news. Large power transformers will warp the chassis if the unit is dropped and not adequately cushioned.

Despite how much you want to scream at the shipping company, poor packing results in the most amount of damage. Even then, I still insure for list price or replacement value, whichever is higher. I also add repair cost to the product value. It increases shipping costs, but that’s a small price to pay relative to the hassle of receiving compensation for damaged equipment.

I’ve long been a believer in stocking common components, which is even more important when an additional person is on the clock. From a facility-management perspective, the same applies, only now the “spares kit” is more likely to include “assemblies” such as redundant hardware (amplifiers, computers, displays, etc.), cards, modules and data drives. MOM has never been more true than it is now.

One look at all the current offerings of retro gear (and the message boards) proves that near-fossilized technology is being reborn and restored at a frenzied pace. I’m starting here because this stuff is the most serviceable due to the historical factor, simplicity and, of course, vintage sonics.

The pots and switches used in vacuum tube and discrete transistor gear generally respond favorably to cleaning and are typically hardwired, so they can be disassembled, evaluated and replaced with off-the-shelf parts. When disassembling pots, look for a tiny carbon contact on the wiper (both U.S.-made Allen-Bradley and its Euro counterpart). If these fall out and are lost, then the pot will be rendered useless. On switches and pots, look for silver or carbon (respectively) that has worn away.

The transition to PCB-mounted components is not great news — especially for pots — on multiple levels. PCB-mounted pots are more susceptible to physical damage than hardwired types. Multi-section pots are considered custom, so if the equipment manufacturer no longer stocks spare parts, see the “ALT_SPARE_PARTS” heading for replacement options.

The Lexicon Prime Time (Model 93) uses a concentric Allen-Bradley “mod pot” for modulation depth and frequency. Aggressive flexing or bashing of the front panel apparently cracked the carbon element. Damage such as this is typical in console modules and rackmount gear. Luckily, the pot was screwed together instead of riveted so I was able to make one good pot from two damaged pots. (The customer gave us three carcasses from which to make a working unit.)

Zooming out from components to modules can change one’s relationship with the equipment. The most obvious and easiest example of “modular” is a recording console, but any device with interchangeable PCBs will do. The goal is to isolate a defective module or PCB and then either have a spare or be able to read a schematic to determine which IC has gone bad. This is oversimplified, of course, but comparative analysis is your friend. An oscilloscope is handy, too.

Interconnections are the least technically complex, but are potentially the most problematic. In the ’70s, manufacturers chose a variety of multipin connectors to facilitate PCB interconnection and replacement. Jones plugs and Molex connectors were MCI’s downfall then, but similar problems plagued the Alesis BRC (ADAT remote control) and, more recently, the Digidesign 002 controller. In the latter two cases, the current requirements of the logic circuitry were too much for the connector, causing the contacts to oxidize, resulting in bizarre, intermittent digital weirdness. Alesis solved the problem by removing the connector and soldering the harness in. Digidesign has upgraded the cable assembly.

One fascinating aspect of connector technology can be found when searching through a manufacturer’s catalog. You may find several contact options for a single connector. For example, a Sound Workshop console’s ribbon cable was outfitted with single-point contact Molex connectors that I upgraded to trifurcated (three-point contact) female connectors and gold male pins.

At this point, whether the gear is vintage or recent will determine the challenge of obtaining spares. One of the biggest intermediaries for spare parts is eBay, which I’ve used for early Sony black-and-white, open-reel video recorders. But be warned that there are people out there buying up gear, assembling a “best of” and then reselling the dregs. Caveat emptor!

The frequency of technological change is constantly increasing. And while it’s possible to technically keep up with the gear, the economics is another story entirely. Build a piece of retro gear and you might as well be in the 16th century — some of the main components can be pricey, plus there’s a good deal of hand assembly.

In contrast, modern robotic assembly methods require a minimum order of 1,000 pieces or so to take advantage of any significant economy of scale. At this level, gear is often too cheap or too complex to repair, so any maintenance focus is on interface (compatibility and troubleshooting), backups and spares.

Troubleshooting down to the component level requires concentration and time — luxuries not often available in “live” environments such as broadcast or performance. This is further hampered by large-scale integration, circuit complexity and miniaturization — all developments that can be intimidating to those who don’t deal with it every day. And unless your organization is particularly well-staffed, there are often too many distractions to allow such work to be completed in a timely fashion.

Eddie is still celebrating his birthday, so if the aroma of eggplant parmigiano drifts your way, surf over to
for a closer look.