Tape is still in high style in the audio world. Like a 1957 Corvette or a standup Pac Man machine, some technical pleasures never go out of fashion.
Although 99% of today’s audio facilities have a DAW as the center of operations, an element of analog tape processing remains a welcome element in a large number of studios.
While many engineers are content to approximate the sound with the wide array of tape-emulating plugins currently available, there’s no shortage of recordists willing to go hard-core with an actual tape machine on hand.
The problem for engineers, producers, studio owners, and archivists who have their heart set on obtaining a tape machine – whether it’s their first or is complementing one or more machines already in-house – is that there are virtually no new models on the market. Save for the Otari Mx5050 MKiii, which is still being made on a limited but costly basis, people who want/need tape will have to obtain a used machine.
So how do you know if that shiny Studer A827 24-track 2” machine that you’ve just discovered for sale on Craig’s List is your dream machine, or a lemon?
One man who can tell quickly is “Midnight Bob” Shuster of Long Island-based Shuster Sound, who stands among the country’s most experienced audio techs. A professional maintenance engineer since 1975, Shuster kept all the gear humming at top NYC facilities including the Power Station, Media Sound, Record Plant, Electric Lady, Sony Studios, Pomann Sound, Avatar, NBC, and many more.
Today, Shuster’s clientele has grown to include an ever-expanding list of solo studio operators and engineers, as well as radio stations, who count on him to keep their analog gear running strong. Tape machine repair and maintenance can account for several of Shuster’s house calls each week, and while some of the newly-obtained Ampex, Otari, Studer, MCI and Scully machines he sees are running clean, others would be more useful as retro coffee tables.
“NYC remains a hotbed of recording, and tape is enjoying a renaissance,” Shuster says. “I’m seeing that up-and-coming engineers, the old-timers, and everyone in between are discovering ways to combine the new and old. And people are saying, ‘I want an analog tape machine, because I know that it can make my record sound better.’”
If you’re thinking of adding a vintage tape machine to your palette, then you need to know what potential pitfalls to watch out for while shopping. Useful maintenance tips are here as well, for those who take the plunge.
Be sure to equip yourself with this essential checklist, as explained by Bob Shuster:
It’s the Heads
A tape machine is only as good as the condition of its tape heads.
Tape heads are the devices responsible for directly recording and playing back the magnetic pattern to or from the tape. Just like a phonograph stylus on a vinyl record (OK, I’m dating myself here), or a microphone, they are transducers. If a head is corroded, rusty or pitted, it will have an effect on the ability to accurately transfer the sound to a magnetic imprint on tape.
Heads can either be relapped or replaced. Relapping is a process of returning the original contour to the face of the head. This is done through a highly refined process of compounding and polishing the head by a skilled specialist.
Re-lapping is obviously the most economical choice, and most headstacks can be relapped between one and three times (depending on the amount of wear on the heads each time). A good test for a worn head is to take your fingernail and run it along the upper or bottom edge of the head — if you can feel a ridge or your nail catches on a ridge, it is a good idea to have it inspected for possible relapping. The exception to this would be an “undercut head” which actually has grooves cut just above the top and bottom of the head cores to help reduce edge wear and protect the tape.
To those unfamiliar with headstacks, it is difficult to explain the differences between head wear and intentionally undercut heads, but it is most easily explained that the undercut head has wide machined grooves which is easy to see. If the head is not undercut, it should have a completely smooth surface and your nail should not catch on ridges. You may also see uneven patterns across the face of the head. Badly worn heads will have grooves at the top and bottom where the tape has travelled and causes level inconsistencies and can even damage the tape.
Another indication of bad heads is that they may not play or record at all and they may be worn beyond what relapping can repair. If you’re not sure about you’re seeing, call somebody in to do an evaluation. If you’ve purchased the deck already, have the heads taken off the machine and send them down to John French of JRF Magnetics in New Jersey – he’s the legend as far as saving tape heads. For illustrations and further information about heads and relapping, visit JRF Magnets at http://www.jrfmagnetics.com.
If it’s too late for relapping, then replacement heads are the ultimate step, but that’s considerably more expensive.
The Tape Path
Next, take a look at the tape path: the reel spindles, incoming guides, impedance rollers, capstans, tach roller, tension arms/rollers, lifters and pinch roller.
Reel Spindles: hold and secure the reels of tape on the machine
Incoming and Outgoing Tape Guides: provide proper positioning of the tape across the heads
Impedence Roller: smooths the tape as it comes off the reel before reaching the heads (See “Image 1” in the gallery following the article)
Lifters: guides that pull the tape away from the heads in fast wind modes to prevent unnecessary wear on the heads. Lifters can also be released for fast wind audible cue. (See “Images 2 & 3” below)
Capstans: provides the precise speed to drive the tape past the heads. Rotational speed and diameter of capstan shaft determines the speed. Most capstans shafts have a dull finish. When they become too polished or shiny, they may cause tape slippage and speed errors. The capstan should be able to be rebuilt or refinished by a specialized motor rebuilding service. One such company is MDI Precision Motor Works, visit at http://www.precisionmotorworks. (See “Image 4 & 5” below)
NOTE: There are two disclaimers to the polished finish “rule” about capstans. There ARE some designed to be polished or shiny. The best way to determine if your machine’s parts were designed as such is to check the entire length of the shaft. If it is uniformly polished, it is probably designed to be so. Other capstan shafts are made from ceramic material and wear out very slowly, if at all. They are white in color.
Pinch Roller: rubber roller that provides proper tension to the tape against the capstan, permitting tape to draw off the supply reel and past the heads at a constant speed. If the pinch roller becomes gummy or cracks, it should be replaced or rebuilt. One of the rebuilding companies I use is Terry Rubber Rollers, at http://www.terryrubberrollers.com.
Tach Roller: (found on more advanced machines) Used for tape read-out/time counter and also monitors the direction of the tape and its speed for transport control. (See “Image 6” below)