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| Dear
Wes, I too have periodically entered the Panasonic twilight zone, but each time I have managed to escape, with just a few less brain cells. Just when I think I can repair anything these machines can dish out, along comes a batch that makes me feel nearly clueless. There are a series of possible answers requiring a reasonable amount of research on your part. You’ve done most of the obvious work, but how old is the machine? Is it pre-’94? The first three characters of the serial number tell the story. “AA4” means 1994. Then look at the case. Is it textured (all machines up ’til late-’94) or smooth (late-’94 and after)? If pre-1994, then did you cut the PCB trace on the servo board? (As per details at www.tangible-technology.com) Have you ever changed the mode motor? What kind of jamming is occurring? Is the left guide hanging up on the tension arm? Have you measured the tension? Does the right guide seem to be stuck in the “loaded” position? These are but a few of the questions you should ask yourself. The first things I look for are the stainless steel “locating pins” at the head of each slant block/precision guide assembly. They are supposed to be press fit, but many come loose. Replacing them is a bear. All service issues ultimately come down to how much you are willing to spend. —Eddie Ciletti |
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After
positioning the loading drawer as shown, this Panasonic SV Series
transport (not applicable to the SV-3500) shows the tension arm
in position to jam the left precision guide assembly. The other
precision guide, on the right side, is obscured by the loading mechanism. Also
note that each guide has a locating pin that can come loose. |
Because tape is made in batches, there are variations to this “ironic” theme—hence, the recommendation that new tapes be fast-wound from end to end before use. Most of the “bad tape” I’ve encountered was sold under the now-defunct DIC brand. As much as we’d like to blame the tape—and people have preferences—there are only a few actual tape (and disc) manufacturers whose products are distributed under several brand names.
Your bad experience may have been batch-related, but often a tape recorder’s condition is more to blame for the intolerance. Familiarity with head and tape path cleaning techniques, combined with the knowledge of electronic monitoring procedures, will make you and your machine less vulnerable to occasional clogs. In future columns, I will be detailing machine-specific tips. Based on these, the astute reader can become less tolerant of problems and more likely to send a machine out for service.
GETTING ALONG IN THE MAGNETIC WORLD
When tape and machine work together as one, you can’t beat them for tangibility. When the marriage fails, we often accuse the tape of poor performance or worse, shedding. In reality, one tape played in several machines will behave differently—some machines are simply more capable than others are at extracting useable data. A “good” machine puts the strongest, most readable signal on tape and, conversely, is capable of extracting the most useable data from any tape. How do you know? Check the Error Rate for starters!
The same applies to all media. There will always be errors—Sony refers to the ability to recover data and tolerate errors without sonic disturbances as “concealment,” the digital data equivalent to “headroom,” the difference between nominal operating levels and clipping.
A METER FOR EVERY TRACK
Record a series of test tones to all tracks of an analog tape recorder, and each meter responds instantly (in most cases) with a “systems” report. In addition, the trained eyes, ears and fingers of a seasoned technician can evaluate mission-critical areas of an open-reel machine and feel its pain without tools. Ballpark tension can be judged by hand. With a good light source, the tape path can be inspected for tape skew at each guide. (Beyond this, tools are suggested!)
Evaluating a digital cassette recorder is never easy. Sony’s PCM-1610 and -1630 formats took advantage of existing video recorder technology—via 3/4-inch U-Matic tape—but from this point forward, the professional user has been insulated from the media and the mechanism. From a pro standpoint, these machines should have kicked DAT into oblivion, yet the 4mm format has proven to be a formidable contender, more reliable than many people give credit to—considering its size and affordability. Remember that DAT is a trickled-up consumer product that was severely compromised during its formative stages by the hyped-up RIAA. (And, yes, I have my own suggestions for Napster et al. Contact info for my two wonderful lawyers is available upon request.)
BIG WORLD HEADROOM
Ages ago (January 1986), this humble technician stepped aboard Le Mobile to play tape op for Joe Jackson’s live album, Big World. The goal of the recording was to capture the live performance—of both the musicians and engineers Michael Frondelli and Guy Charbonneau—to stereo while running 24-track analog only as backup. The 2-channel digital recording was made via Sony’s PCM-1610 converter/processor and two U-Matic rental decks.
After the show, a quick spot check confirmed a clean recording; a relief, until the tapes were swapped. Playback in the opposite machines was not inspiring. Compatibility was fair with occasional and inconsistent dropouts. The machines were black boxes to me. Now I understand that poor alignment was the reason for the erratic performance.
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Reprinted with permission from
Magazine, March, 2001© 2000, Intertec Publishing, A Primedia Company All Rights Reserved
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