Way of the Dragon

Sound & Vision - - CONTENTS - ROB SABIN

We revisit Stereo Re­view’s April 1983 re­view of Nakamichi’s Dragon, a le­gendary cas­sette deck that in­spires lust in vin­tage gear col­lec­tors.

IF YOU WERE AN AU­DIO­PHILE in the late 1970s or early 1980s—or just a teenager with a fresh driver’s li­cense—the

Com­pact Cas­sette was in­te­gral to your life. While reel-to-reel mag­netic tape in­tro­duced the con­cept of the “mix­tape” decades ear­lier, it was not un­til the cas­sette’s launch by Philips in 1963 and its later adop­tion in au­to­mo­bile decks and porta­bles in the 1970s that mu­sic lovers got the abil­ity to cre­ate per­sonal playlists and take them to-go in a con­ve­nient, pocket-friendly for­mat.

But eek­ing out high-fi­delity from a de­sign that traded a con­sumer reel-toreel’s 1/4- inch wide tape and typ­i­cally 7 1/ 2 inch-per-sec­ond max­i­mum speed for a 0.15-inch strip run­ning at a mea­ger 1 7/ 8 inches per sec­ond was not with­out chal­lenges. Dolby B noise re­duc­tion, re­leased in 1971 in Ad­vent’s Model 201 cas­sette deck, was a step in the right di­rec­tion, as was the in­tro­duc­tion of three-head decks with ded­i­cated heads for erase, record­ing, and play­back. Dual-cap­stan decks re­duced speed vari­a­tions by grab­bing the tape on both the feed and take-up sides of the head clus­ter. Even­tu­ally, new metal tape for­mu­la­tions fur­ther im­proved per­for­mance. Still, se­ri­ous hur­dles re­mained. Notably, the small size and physics of the cas­sette calls for near-per­fect align­ment of the ver­ti­cal gap in the play­back head across the width of the tape. Any mi­nor vari­ance from per­pen­dic­u­lar­ity re­sults in a po­ten­tially dra­matic loss of high fre­quen­cies. To make mat­ters worse, the ideal cas­sette deck needs to re­tain that “az­imuth” align­ment even af­ter the tape is turned over or the tape di­rec­tion re­versed (and/or the head flipped) for play­ing of the B-side. Fur­ther­more, mi­nor az­imuth dif­fer­ences be­tween the angle of the play head and that of the orig­i­nal record­ing deck (a given with pre­re­corded cas­settes) un­der­mines any at­tempt to tune the deck for per­fect re­peata­bil­ity.

For­tu­nately for au­dio­philes, these and other ob­sta­cles indigenous to the cas­sette be­came a source of fas­ci­na­tion for Niro Nakamichi. The com­pany bear­ing his name was founded by his brother Es­turo in 1948 as a re­search out­fit be­fore it veered into reel-to-reel tape deck de­sign in the 1950s. But it was Niro who later took over and gave the firm its great­est fame as provider of the world’s finest (and most ex­pen­sive) cas­sette decks. Among these, none was as her­alded or lusted af­ter as the Nakamichi Dragon.

Al­though the deck in­te­grated sev­eral prior Nakamichi ad­vances, what came to­gether in 1982 in the $1,850 Dragon (later repriced to $2,499) was noth­ing short of an en­gi­neer­ing mar­vel. Among its fea­tures was a belt­less and spring­less dual-cap­stan trans­port with di­rect-drive mo­tors con­trolled to re­mark­able ac­cu­racy by a quartz clock; the mech­a­nism in­ten­tion­ally pushed away the cas­sette’s trou­ble­some built-in pres­sure pad (nor­mally in­tended to im­prove tape-to-head con­tact) and re­lied solely on the mo­tors to pro­vide the de­sired pres­sure. In Stereo Re­view’s April 1983 re­view, writ­ten by Craig Stark of Stark­sonic Stu­dio (who had by then taken over tape deck re­views to ease Ju­lian Hirsch’s bur­den) and re­pro­duced here, the Dragon’s

mea­sure­ments re­vealed the low­est wow-and-flut­ter of any cas­sette deck ever tested. But, as you’ll read, its big­gest break­through was the in­clu­sion of Nakamichi Auto Az­imuth Cor­rec­tion (NAAC), a mi­cro­pro­ces­sor-driven sys­tem that used a clev­erly-de­signed feed­back loop to de­tect az­imuth er­ror in real time and phys­i­cally cor­rect it with a servo-con­trolled head, thus en­sur­ing per­fect align­ment even with pre­re­corded tapes!

Fairly quickly, the com­plex and costly me­chan­ics of NAAC tech­nol­ogy and the dif­fi­culty of ser­vic­ing these auto-re­verse machines caused Nakamichi to aban­don it in its RX se­ries of UDAR (Uni-di­rec­tional Auto Re­verse) decks, which me­chan­i­cally flipped the cas­sette to best main­tain az­imuth ac­cu­racy. But the Dragon held on, fi­nally ex­it­ing the mar­ket in 1993 af­ter an 11-year run. Nonethe­less, with the rapid ad­vance of the Com­pact Disc in the late 1980s and early 1990s, the de­mand for Nakamichi’s cas­sette decks waned, and the new dig­i­tal au­dio tape (DAT) for­mat it banked its fu­ture on failed to gain trac­tion with con­sumers. The com­pany even­tu­ally lost its fi­nan­cial foot­ing and dis­ap­peared. Af­ter years of dor­mancy, the brand is now con­trolled by Grande Hold­ings, a Chinese firm based in Hong Kong that of­fers the Nakamichi Shock­wafe se­ries of high-per­form­ing sound­bars (see our test at soun­dand­vi­sion.com) and other lifestyle elec­tron­ics.—

THE DRAGON is the first Nakamichi cas­sette deck to be given a name rather than a model num­ber, and if the in­tent was to sug­gest an awe-in­spir­ing cre­ation, the tech­no­log­i­cal in­no­va­tions it em­bod­ies make “Dragon” a won­der­fully apt des­ig­na­tion. It is the com­pany’s first recorder to feature auto-re­verse play­back and the first from any man­u­fac­turer with con­tin­u­ous au­to­matic play­back-head az­imuth align­ment.

The Dragon’s record and play­back heads are made of Crys­tal­loy, and they are en­tirely sep­a­rate units whose gap widths (3.5 and

0.6 mi­crom­e­ters, re­spec­tively) are op­ti­mized for their dif­fer­ent func­tions. The three-head de­sign also per­mits im­me­di­ate com­par­isons be­tween the in­com­ing sig­nal and the recorded re­sult. The near and far edges of the head faces are slot­ted so that no “wear groove” can de­velop dur­ing their life time, and the play­back head is fit­ted with a lifter that pushes the cas­sette’s pres­sure pad out of the way when the heads en­gage the tape. Re­mov­ing the in­flu­ence of the pres­sure pad elim­i­nates a po­tent source of scrape noise but re­quires an un­usu­ally pre­cise dual-cap­stan drive sys­tem.

All these head-de­sign fea­tures have been in­cor­po­rated in Nakamichi decks for sev­eral years, though the use of a four-track play­back head (two tracks for each di­rec­tion of tape travel) is new. Over­all, how­ever, the Dragon’s play­back-head de­sign is ut­terly unique in our ex­pe­ri­ence and sets an ex­am­ple we hope other man­u­fac­tur­ers will em­u­late. Un­der­stand­ing this tape head and the NAAC (Nakamichi Auto Az­imuth Cor­rec­tion) mech­a­nism that goes with it re­quires a lit­tle ex­pla­na­tion.

Ideally, all tape heads, whether for record­ing or play­back, should be aligned so that their head gaps (where the mag­netic ac­tion takes place) are ex­actly per­pen­dic­u­lar to the axis of the tape. The record­ing and play­back gaps are then par­al­lel to each other. When this con­di­tion is not met there is an “az­imuth er­ror,” the re­sult of which is a loss in high-fre­quency re­sponse. In the cas­sette for­mat, an az­imuth er­ror of only a quar­ter of one de­gree, while hav­ing no mea­sur­able ef­fect at I khz, causes a 14.6-db loss at 15 khz and a 25.5-db loss at 17 khz, so its se­ri­ous­ness is ob­vi­ous.

Even if a deck’s head gaps are per­fectly aligned, cas­sette shells are no­to­ri­ously im­per­fect; they all phys­i­cally skew the tape to some de­gree, cre­at­ing az­imuth er­rors. This skew­ing is not con­sis­tent from one cas­sette to the next and, in­deed, even varies some­what as the tape plays through a sin­gle side. The most ob­vi­ous skew-in­duced az­imuth er­rors, how­ever, tend to be be­tween the two sides of the same cas­sette. No mat­ter

how care­fully you align the play­back head for one side, there is likely to be an ap­pre­cia­ble tre­ble loss on the other. To min­i­mize skew-in­duced az­imuth er­ror in cas­settes recorded and played back on the same deck, a num­ber of Nakamichi (and some other) decks have for some years pro­vided ei­ther man­ual or au­to­matic record­ing-head az­imuth ad­just­ments, so that no mat­ter how the play­back head is aligned, the record­ing head will lay down a match­ing track. But this sys­tem, though ef­fec­tive, re­quires record­ing a test sig­nal and thus can­not help with pre­re­corded tapes. And the cas­sette shells used by tape du­pli­ca­tors tend to be far worse in all re­spects than those you get with a premium blank tape.

The Nakamichi so­lu­tion, em­bod­ied in the Dragon, starts by split­ting the in­side tracks of the play­back head (which pro­vide right-chan­nel sig­nals for each di­rec­tion) into two elec­tri­cally sep­a­rate halves with their own play­back gaps. In­stead of only one gap “scan­ning” the 0.021-inch-wide right-chan­nel tracks as on a con­ven­tional tape deck, there are two. As long as the play­back head and the tape are cor­rectly aligned, with no rel­a­tive az­imuth er­ror, the out­put from these two gaps will be iden­ti­cal. But if the play­back head is at all tilted rel­a­tive to the recorded track, the sig­nal on the tape will ar­rive at one of them be­fore the other. This cre­ates a phase dif­fer­ence be­tween the two gaps, which is am­pli­fied within the Dragon and used to con­trol a mo­tor that pushes or pulls a flex­i­ble stain­less-steel band in­side the deck. This band, in turn, drives a mech­a­nism that ad­justs the head az­imuth so as to elim­i­nate the phase er­ror and thereby match the play­back head’s az­imuth with that of the tape. The cor­rec­tion process is con­tin­u­ous dur­ing the record­ing or play­back of a cas­sette. (Only the in­side tracks are used in this process since the sig­nals from the out­side, left-chan­nel tracks can be too unreliable due to tape dam­age.)

The con­struc­tion of such a head and the au­to­matic ser­vo­mech­anism that goes with it is an en­gi­neer­ing tour de force, al­though, like all good en­gi­neer­ing so­lu­tions, it is el­e­gantly sim­ple in con­cept. The play­back head sim­ply au­to­mat­i­cally ad­justs its az­imuth to com­pen­sate for any er­ror it finds, whether it stems from the record­ing head next to it or from one in a tape du­pli­ca­tor’s plant, from a shift in tape di­rec­tion or from cas­sette-shell im­per­fec­tions or tape-path vari­a­tions dur­ing the play­ing of a cas­sette.

If less dra­matic than the au­to­matic az­imuth ad­just­ment, the drive sys­tem in the Dragon is no less so­phis­ti­cated. There are two di­rect-drive mo­tors with a unique, con­stant- torque de­sign in a closed-loop, dual-cap­stan ar­range­ment. Con­stant tape ten­sion is achieved by a 0.2 per cent speed dif­fer­en­tial be­tween the sup­ply and the take-up cap­stan mo­tors, which are gov­erned by a quartzref­er­enced phase-locked-loop cir­cuit. The in­tent is to lower wow and flut­ter al­most to the van­ish­ing point—and our mea­sure­ments in­di­cate that the at­tempt is spec­tac­u­larly suc­cess­ful.

Cas­settes are in­serted, open­ings down­ward, into the fa­mil­iar cas­sette-well­door slides. When the door is closed a mo­men­tary drive pulse is sup­plied to take up any slack in the tape wind­ing. The well is ac­ces­si­ble for head clean­ing and is il­lu­mi­nated, though la­bel vis­i­bil­ity is poor. Trans­port con­trols are ar­ranged some­what like rows of shin­gles on a roof, mak­ing for easy op­er­a­tion. A mo­tor re­places the con­ven­tional so­le­noids to ac­ti­vate the var­i­ous modes, re­sult­ing in smoother, qui­eter op­er­a­tion. In the fast-wind­ing modes a CUE but­ton slows the tape to about a third of its nor­mal fast-wind speed and brings the heads close enough to it to pick up the pro­gram ma­te­rial faintly. De­press­ing one of the fast-wind­ing con­trols a sec­ond time while cue­ing slows the tape still fur­ther and per­mits you to jockey the tape back and forth to find the be­gin­ning of a recorded se­lec­tion. The mem­ory-rewind feature backs the tape a counter unit or so be­yond the 0000 in­di­ca­tion on the LED read­out, then ad­vances it to the se­lected spot. All trans­port con­trols have in­di­ca­tor LEDS, and ad­di­tional tape-di­rec­tion in­di­ca­tors are pro­vided on the cas­sette-well door. (The lat­ter flash as the NAAC sys­tem cor­rects a large er­ror.)

Record­ing level is shown on a twen­ty­seg­ment peak-in­di­cat­ing flu­o­res­cent dis­play cal­i­brated from— 40 to + 10 db. Dur­ing tape ad­just­ments the me­ter’s dy­namic range is re­duced and its res­o­lu­tion in­creased. The ad­just­ments them­selves uti­lize built-in 400-Hz and 15-khz test-tone gen­er­a­tors and are de­signed to en­sure op­ti­mum bias and con­sis­tent sen­si­tiv­ity for fer­ric, chrome-type, and metal tapes. The ad­just­ment sys­tem has il­lu­mi­nated LEDS to in­di­cate the proper knobs to be turned, and it was easy to use and ac­cu­rate.

Push­but­tons are pro­vided to se­lect be­tween tape and source mon­i­tor­ing, 120- or 70-mi­crosec­ond play­back equal­iza­tion, and Dolby-b, Dolby-c, or no noise re­duc­tion, as well as to ac­ti­vate an Fm-mul­ti­plex fil­ter and an in­fra­sonic fil­ter de­signed to elim­i­nate the ef­fects of turntable rum­ble. There is an au­to­matic record-pause switch that causes the deck to stop about 15 sec­onds af­ter the end of the mu­sic you are record­ing, in case you are oth­er­wise oc­cu­pied at the time.

Other push­but­tons con­trol the mem­o­ryrewind/play and auto-re­verse fea­tures. An out­put-level con­trol (which also af­fects the sig­nal at the front panel’s head­phone jack) is pro­vided, and the com­bi­na­tion of sep­a­rate left- and right-chan­nel record-level con­trols with a mas­ter record-level con­trol fa­cil­i­tates level set­ting. In ad­di­tion, an au­to­matic 2- or 6-sec­ond fade up or down can be ac­ti­vated dur­ing record­ing. As is now cus­tom­ary on Nakamichi recorders, how­ever, there are no mi­cro­phone jacks or con­trols; an ex­ter­nal mixer is needed for this kind of record­ing. Timer ac­ti­va­tion in ei­ther record or play mode is also switch-se­lectable.

The rear panel of the Dragon con­tains the line-in and line-out jacks, a jack to power an ex­ter­nal mi­cro­phone mixer, and another jack for a re­mote-con­trol ac­ces­sory. The deck mea­sures 17 3/ inches wide by 5/ inches 4 16 high by 11/ inches deep, and it weighs 16 ap­prox­i­mately 21 pounds. Price:$1,850.

LAB­O­RA­TORY MEA­SURE­MENTS. Our sam­ple of the Dragon was sup­plied with the three Nakamichi tapes used in its orig­i­nal setup and check­out: EX-II (fer­ric), SX (chrome-equiv­a­lent fer­ri­cobalt), and ZX (metal). These are the tapes we used for all our record-play­back mea­sure­ments. Be­cause of the Dragon’s ex­cel­lent bias and sen­si­tiv­ity ad­just­ment sys­tems, how­ever, we were able to ob­tain vir­tu­ally iden­ti­cal re­sponse curves from a va­ri­ety of premium tape for­mu­la­tions, in­clud­ing: Max­ell XLI-S, TDK AD, Fuji FR-I, and Me­morex MRXI (fer­ries); TDK SA, Max­ell UDXL-II, BASF Pro­fes­sional II, and Sony UCXS (Cr02-equiv­a­lents); and TDK MA, Sony Metal­lic, Fuji AR Metal, and the new Scotch XSM IV (metal).

Play­back fre­quency re­sponse was checked with our IEC stan­dard fer­ric (120-μs) and chrome (70-μs) cal­i­brated tapes. Dif­fer­ences be­tween for­ward- and

re­verse-di­rec­tion re­sponse with ei­ther tape were so slight that we could sim­ply take an av­er­age to ar­rive at the curves shown in the graph. Up to l0khz both are within 1 db of stan­dard­ized re­sponse from the 31.5-Hz lower limit of the test tapes; above 10 khz, how­ever, there is a clearly ris­ing re­sponse (± 3.7 to 4.2 db at 18 khz), which we have found char­ac­ter­is­tic of Nakamichi decks. This may make some pre­re­corded tapes sound slightly over-bright, but it can eas­ily be cor­rected with a tre­ble con­trol.

Over­all record-play­back re­sponse, mea­sured at a —20-db level, was within ± 1 db from 20 Hz to be­yond 20 khz with all three tape types, which is truly re­mark­able cas­sette-deck per­for­mance. Dolby track­ing er­ror— the dif­fer­ence in fre­quency re­sponse with and with­out the noise-re­duc­tion sys­tem—was within 1.5 db from 20 Hz to 20 khz us­ing ei­ther Dolby-b or Dolby-c. Even at the 0-db level, where all cas­sette tapes run into sat­u­ra­tion at the high­est fre­quen­cies, re­sponse did not drop to —6 db un­til 13.2 khz for the fer­ri­cobalt SX, 14 khz for EX-II (fer­ric), and 18 khz for ZX (metal). In­deed, though not shown on the graph, with metal tape and Dolby-c, the Dragon’s re­sponse at a 0-db record­ing level was down only 2 db at 20,000 Hz!

Wow-and-flut­ter in the Dragon was the low­est we have ever mea­sured in a cas­sette deck. With our Teac MTT-1 11 flut­ter test tape the read­ings were 0.016 per cent (weighted rms) and 0.024 per cent (DIN peak-weighted) in ei­ther di­rec­tion. We sus­pect this must be the resid­ual level on the test tape it­self. On an over­all record-rewind­play­back ba­sis, how­ever, wow-and­flut­ter was only 0.0 17 per cent wrms (0.028 per­cent DIN peak-weighted) in the for­ward di­rec­tion, 0.022 per­cent wrms (0.03 per cent DIN peak-weighted) in the re­verse mode. At a 0-db record­ing level the third-har­monic dis­tor­tion of a 315-Hz tone mea­sured 0.35, 0.88, and 0.4 per cent, re­spec­tively, for the Nakamichi EX-II, SX, and ZX tapes. To reach the 3 per­cent dis­tor­tion point used to cal­cu­late the sig­nal-to-noise ra­tio (S/N) re­quired in­creas­ing the recorded level by 5.8, 3.8, and 8.4 db, re­spec­tively, and the Dragon’s man­ual sug­gests that for fer­ric and Cr02-type tapes peaks should be al­lowed to reach a + 5-db in­di­ca­tion, +8 db for metal. Us­ing the 3 per­cent dis­tor­tion ref­er­ence, S/N’S for EX-II, SX, and ZX mea­sured 50.7, 52, and 55.6 db, re­spec­tively, with no noise re­duc­tion and no weight­ing. With Dolby-b and CCIR-ARM weight­ing, the S/N fig­ures were 64.3, 66.2, and 68 db, and Dolby-c in­creased them all the way to 73.9, 75.5, and 77.5 db. As with many of our other mea­sure­ments on the Dragon, these noise fig­ures sim­ply de­fine the cur­rent state of the art in cas­sette-deck per­for­mance. The

0-db out­put level of the Dragon was 1 volt and re­quired a line-level in­put of 55 mil­li­volts. Fast-for­ward and rewind times were very rapid, av­er­ag­ing 51 sec­onds for a C-60 cas­sette and 73 sec­onds for a C-90.

The up­per curves in­di­cate over­all record-play­back re­sponse at the man­u­fac­turer’s in­di­cated 0-db record­ing level us­ing the tapes des­ig­nated on the graph. In the cen­ter are the same mea­sure­ments recorded at —20 db rel­a­tive to the up­per curves, a level con­ven­tion­ally used for tape-deck fre­quency-re­sponse mea­sure­ments. Bot­tom curves show play­back re­sponse from cal­i­brated test tapes and in­di­cate per­for­mance with pre­re­corded tapes.

COM­MENT. We found that the Nakamichi Dragon sounded ev­ery bit as good as it mea­sured, and it han­dled as well as it sounded. With pre­re­corded tapes from In-sync, Mo­bile Fi­delity, and Nakamichi’s own con­cert hall in Ja­pan, there was a kind of trans­parency and bril­liance (which sur­vived even af­ter we turned our tre­ble con­trol down a tri­fle) that we al­most never hear from cas­sette record­ings. Be­cause it op­er­ates con­tin­u­ously, the ef­fect of the NAAC cir­cuit with its split sec­tion play­back head is usu­ally sub­tle; ex­cept for when a flash­ing tape-di­rec­tion light in­di­cates that a large mis­align­ment is be­ing cor­rected, you have to lis­ten very care­fully to note the restora­tion of the high fre­quen­cies. But the dif­fer­ence in high-end re­sponse with pre­re­corded ma­te­rial be­tween the usual fixed az­imuth of another top-rated Nakamichi deck and the Dragon’s adap­tive az­imuth sys­tem is both mea­sur­able and au­di­ble, and it is on such small, yet real, im­prove­ments in the state of the art that Nakamichi’s rep­u­ta­tion is founded.

As for the deck’s over­all record-play­back per­for­mance, per­haps the best word is im­pec­ca­ble. Us­ing metal tape and Dolby-c, there was only one test source with which we could hear a clear dif­fer­ence be­tween the in­put and recorded out­put: a pure but mu­si­cally bor­ing, 1-khz sine wave from an au­dio gen­er­a­tor. Not even a 15-ips pro­fes­sional ana­log mas­ter­ing recorder with Dolby-a can pass this test, how­ever.

True, we could pick nits. The view­ing area in the cas­sette-well door is too small to be able to read the la­bel, and, like all seg­mented record­ing-level dis­plays, that of the Dragon is an­noy­ingly im­pre­cise when one is try­ing to mea­sure dif­fer­ences within 1 db. It also would have been in­ter­est­ing to have some in­di­ca­tion as to the de­gree of mis­align­ment in our pre­re­corded tapes, not just a flash­ing light telling us that an az­imuth cor­rec­tion was tak­ing place.

Over­all, how­ever, the Nakamichi Dragon is sim­ply the finest cas­sette deck we have yet tested. No doubt there will be chal­lengers for that ti­tle, but they will be up against a real fire-breath­ing cham­pion when they ap­pear.—

Along with the Dragon, Stereo Re­view’s April 1983 is­sue fea­tured a test of another tech break­through: Sony’s SL 5200 Beta Hi-fi VCR.

Nakamichi’s Auto Az­imuth Cor­rec­tion (NAAC) sys­tem, a new feature that de­buted with the Dragon, en­sured per­fect tape head align­ment, even with pre­re­corded tapes. Wow-and-flut­ter was the low­est SR had yet mea­sured in a cas­sette deck.

Draw­ing (not to scale) shows split right chan­nel play­back-head gaps (red) that pro­vide the az­imuth-angle er­ror sig­nals.

Newspapers in English

Newspapers from USA

© PressReader. All rights reserved.