Supplement TEAC
Supplement TEAC
The purpose of this booklet is to supply a fund of information that will increase your knowledge of and interest in open reel
tape decks. We realize that no manual this size could possibly answer every question you may have nor cover every feature and
technique used today. But, if this booklet helps you to enjoy your deck a little more, its basic purpose has been achieved.
-CONTENTS-
page 2 Tape Tracks and Channels on Open Reel Tape Decks
4 Introduction (Part 2)
11 About Dolby NR
13 Owner's Care
ENVIRONMENTAL CONSIDERATIONS
Your TEAC deck is well constructed and is adaptable to a wide range of conditions, but a few cautions should be observed to insure proper
operation and prolong unit's useful life.
TEMPERATURE EXTREMES
Do not operate the deck at temperatures above 100/F (38/C) or lower than 40/F (5/C). Direct sunlight, stoves, or heating devices nearby will
also raise the internal temperature of the deck which may cause damage to some components. Low temperatures may cause sluggish
operation and place an overload on the drive mechanism.
DUSTY ENVIRONMENTS
As with any precision machine having moving parts, your deck should be covered when not in use. Excessive dust may result in bearing or
tape head wear. Also protect yourtapes from dust.
HIGH HUMIDITY AND OCEAN SALT AIR
High humidity conditions will shorten equipment life from corrosion and possible fungus growth on the printed circuit boards. If near the
ocean, extra care should be taken to cover your deck after use. Covering will prevent salt air from corroding metal surfaces, especially the
bearings and internal connections.
EXTREME LINE VOLTAGE FLUCTUATION
If you are in an area where line voltage fluctuation is severe, the use of a voltage controller (VARIAC) may be advisable.
Tape Tracks and Channels of The Open Reel Tape
Decks
1. Full track recording: The magnetic flux pattern produced by the head covers almost the whole surface of the tape. The entire tape
is recorded in one direction on ly.
2. Half track mon ophon ic: The flux pa ttern generated by the he ad co vers less than half of the tape surface and the recording head is
off-set to one edge of the tape. A monophonic signal is recorded on one half of the tape and then the reels are inter-changed and the
other half of the tape is record ed. T he sam e half track head is used fo r both passes. The tracks are, o f course, reco rded in opp osite
directions on the tape.
3. Half track stereo: Two reco rding sections (heads) are used to record two tracks simultaneously on the tape. Both channels are
recorded in the same direction on one pass through the tape.
4. Quarter trac k, 2-channel stereo: 2 record heads are used to record all 4 tracks on the tape. On the first pass through the tape, track
1 and 3 are recorded simultaneously. At the end of the first pass, the reels are inter-changed and tracks 2 and 4 are recorded using the
same two heads tha t recorded tracks 1 and 3 . The actua l program o n the tap e for trac ks 1 an d 3, and 2 and 4 is recorded in opp osite
directions but since the reels are inter-changed between passes, the tape is recorded and played in the forward direction for both passes
of the tape.
5. Quarter trac k, 4-track/4-channel (Qua drapho nic): The head assembly consists of 4 separate heads and all 4 tracks can be
recorded at the same time on a single pass through the tape.
6. Quarter trac k, single channel (Mo nopho nic): The 4 tracks on the tap e are reco rded o ne track at a time. At the end of each pa ss
through the tape the reels are interchanged and the next track is recorded. The order in which the tracks are recorded is 1, 4, 3 and 2.
Four track re cord ing gives maximum playback time how ever, the bene fits of stereo repro duction are lost.
DIAG RAM A.
Playback compatibility
Diagram A shows the relative track locations and dimensions on a standard prerecorded 1/4" open reel tape. The playback heads
closely correspond to the record heads depicted in the diagram. Some decks in fact use the same record head for playback also. A brief
study of the track locations and recording sequence for the various common tape formats will lead to many valid conclusions
concerning compatibility between various tapes and tape decks. Some of these conclusions are stated briefly below.
1. A half track mono deck can playback a pre-recorded full track tape.
2. A half track stereo deck can play either a full track or a half track tape but the signal from a half track mono tape on side 2
will be played b ack in the opposite direction. H owever, the right channel output can be turned dow n and the left channel only
used for playback of both sides of the tape. When playing a furl track tape the left and right channel will reproduce the same
sounds.
3. A four track stereo tape deck can playback bo th 4 track and 2 track tapes and from the p oint of compatibility has the widest
possible range of utilization. W hen playing a 2 track stereo tape on a 4 track recorder, track #1 will be completely covered by
the head. Track #2 will be slightly off alignment but stereo can still be enjoyed by compensating for the slight loss of track #2
volume with the volume or balance controls of the amplifier. On the other hand a four track tape cannot be played back on a
two trac k reco rder as bo th tracks #1 and #2, and #3 and #4 will be repro duced together resulting in m ixed unintelligible
sound.
There are of course other possibilities for playback compatibility that the inventive audiophile or home recordist can discover by
co nsulting this diagram and o ther sources. T he proc ed ures for recording in each of the various formats will be covered in the Owner's
Manua l supplied with each TE AC deck. T his section is intended to give the interested recordist a complete overview of standard
recording tape forma ts.
Almost all tape decks are designed and constructed to record and playback only one of the standard formats. A few 4-channel decks
have a selectible 2-track playback head for compatibility with pre-recorded 2-track tapes. Full track and half track monopho nic decks
for home use are rarely, if ever, available today. Full track professional decks may be purchased however.
Introduction to Open Reel Tape Decks
Open R eel
Many articles have been written concerning the relative merits of open reel decks vs cassettes decks. Some of these articles have even
selected one or the other as being better. Our position, at TEAC, is that both types are excellent, can give good service and provide
many months and even years of recording and listening pleasure. A large number of audiophiles own both an open reel deck and a
cassette deck. Cassette decks have many advantages and features that continue to attract customers (especially convenience and price).
Open reel decks also have capabilities and features that appeal to many serious audiophiles. Here are some of them. Features such as
separate Record/Playback heads, Editing and cueing controls, mic-line mixing, monitoring functions, provide versatility for many
creative recording situations. The mo dern audiophile doesn't seem to be content to just record performances as they are. He or she
wants to create, to experiment, to modify. They want to put something of themselves into their recordings. The pro or semi-pro
recordist will find the high end performance and versatility a distinct advantage. Few, if any, records are made today directly from a
single live performance. A singer's voice is recorded at one time, instruments are added or changed, a chorus may be added and often
other special effects are mixed in. The final recording may be completely unrecognizable by the artist who sang the original song.
The higher speeds of the open reel decks make possible higher quality recordings which challenge the limits of one's entire stereo
system.
The quality, styling and price of open reel decks make them prestige items. A well designed open reel deck seems to blend in with the
most expensive furniture decor and even enhances the overall atmosphere of successful living. There are various head types and
co nfigurations. T his sectio n is intend ed to give you a basic idea of how som e of the systems op erate. Please consult your owner's
manual for complete details of the features and capabilities of your deck.
IM PO RT AN T: E diting will destroy o r seriously "cut" any ma terial recorded on the other side of the tap e (track s 2 & 4). If editing is
anticipated, record only on one side of the tape. After editing, material can then be copied onto both sides of another tape. When
attaching blank "leader" tape onto your tapes, follow the same procedures given here for splicing.
Bias and Equalization-General Theory
Bias
In order to get the magnetic particles on a tape to respond properly to the changing signal supplied to the record head, a pre-
conditioning bias is needed. Most home recorders today use an alternating current (AC) bias at a frequency of 50 to 150kHz. This bias
raises the magn etic level of the oxide p articles so that even small changes in the signal from the record head will cause relatively
similar changes in the magnetic level of the particles on the tape. Without this bias pre-conditioning, the oxide particles do not respond
properly to the signal from the record head. This high frequency bias signal is applied to the tape together with the desired audio signal
by the record head. Since the bias signal frequency is much higher than the audio frequency range, there is little chance that the bias
signal will interfere with the sound reproduction.
The amount of bias (bias level) affects the signal-to-noise ratio, distortion and the frequency response of the tape and hence of the deck
itself. To o little bias w ill allow more d istortion than is necessary. Bias also affects the output level of the tape. N ormally, as bias is
increased the signal level off the tape increases, up to a maximum output level which depends on the type and quality of the tape.
Increasing the bias level beyond this point causes the output level (and consequently, the S/N ratio) to decrease. The "optimum" level
of bias is usually a comp romise betw een the best results in S/N ratio, distortion and high frequency respo nse, and usua lly differs with
different types and brands of tape. For this reason, all TEA C tape decks offer the user a switch selection for different bias levels or a
bias adjustment. One or the other of these is absolutely necessary if the recordist expects to use more than one type of tape. If everyone
used the same type and brand of tape, the tape deck manufacturers could all set their bias circuits for a specific type of tape and
everything would be fine. But, there are many good brands and types of tapes available and many recordists use more than one type of
tape. E xperience and experimentation will help you dec ide which tape to use and w hat bias level is most appropriate
for specific situations.
TEA C offers charts and/or instructions on how to set the bias level for various brands of tape. These instructions should be followed
until the recordist develo pes sufficient knowledge (and has the p roper m easuring equipment) to make reliable tape evaluations.
Equalization
The EQ (equalization) selection must also match the type of tape formulation being used. If for instance, a deck was factory adjusted
for standard tapes and the recordist decided to use low noise/high output tapes with their accompanying high frequency emphasis, the
high freq uencies would sound to o bright.
The equ alization switch can be used to reduce this high frequency over-emphasis and resto re the o utput sign al to its original fidelity.
Conversely, if the deck is factory adjusted for low noise/high output tapes and the recordist decided to use standard tapes, the high
frequencies will be much lower and an equalization setting that emphasizes high frequencies should be selected to compensate for
these low levels. TEAC tells in our instruction manual what equalization level should be selected for various types of tape. Together
with the b ias setting, the suggestions sho uld be close ly adhered to until the audiop hile develop es the ex perience and knowledge to
decide for himself.
Freq uency Response
Frequency response is one of many parameters or specifications that manufacturers consider in the design of their open reel tape
decks. B ut it is possible to over-emp hasize this one parameter at the exp ense of others, such as signal to-noise ratio. In general, it's best
to consider a well designed tape deck as a series of compromises that are made to give the best overall operation and performance. The
following musical sound frequency chart will help you understand the basic requirements of frequency response versus actual
recordable frequencies.
4-Channel Tape Decks
Introduction to Quadraphonic Sound
Pro pon ents of q uadraphonic so und m ay ove rwhelm the newcom er with high soun ding words like "sp atial effect, am bienc e, music hall
realism" or " surround sound" . In simple terms, the philoso phy behind the emergen ce of quad raphonic sound goes like this.
W hen a perso n attends a concert or other m usical production in an auditorium or concert hall he hears sounds from m any directions.
The primary or most significant sound originate from the direction of the orchestra, but there are also reflected sounds which one hears
from many other directions, including the sides, top and rear of the hall. The sound from the top and sides of the hall are often
insignificant because the primary sounds from the front tend to over-ride them. However, the sounds from the rear seem to add a
special dimension to the performance and give a sense of space and position to the listener. Without these rear sounds the "ambience"
of the auditorium would be lost and the listener would not enjoy the realism of being in the audience. To accurately record all of the
dimensions one "feels" at a live concert requires many channels but as a practical limit due to both space at home and financial
restrictions, 4 channels was determined to be the minimum number of channels required. These are the two front primary stereo
channels and two more rear channels that give the sense of position, ambience or "music hall realism".
Another use of 4-channel sound has also been investigated by some peo ple. T his is "surround sou nd". Althou gh the " music hall
ambience" concept and "surround sound" are often considered the same thing, there is a difference. The music hall ambience concept
attempts to put the listener in the audience at a concert or musical performance. The idea is to faithfully record and reproduce the true
sounds and realism of the hall. The sounds heard from each channel are b asically the same, with only a slight (though imp ortant)
difference in reverb eration, volume level and aco ustic phases.
Surro und so und b y contra st tries to put you in the ban d and even a llows you to "w alk through the band ". T he sounds on the 4 channels
are often quite different. A piano may emanate from channel 1, a bass may dominate channel 2 and channels 3 and 4 may contain other
sounds. The instruments and the volume levels may vary on each channel and the listener may get the impression that he is moving
around in the orchestra, some music experts call this type recording "gimmickry". Some others will say this type of 4-channel sound
provides vastly expanded creative p ossibilities.
10-1/2" reel
When the input level (an audio signal of a specified voltage) is very low
or weak, it must compete with the hiss and noise always present at the
same low level on the tape. Stronger input levels, are recorded above
this tape noise and tend to cover or "mask" it so you hear only the
desired sound during playback. If the input level is too high, it enters
the region shown at the top of the chart, which represents the limits of
the tape. This limit says that no matter how much stronger you record,
the tape cannot accept and re turn the sa me strength of signal. T he result
is known as "sa turation distortion", and is heard as a garb led or harsh
sound. T he dynam ic range available is found betwee n this distortion at the high end and the noise at the low end . As the chart also
shows, there is a difference between recording tape. The tape on the left is representative of conventional or normal recording tape. To
the right is the improved kind of low noise/high output tape.
Input Level Controls (MIC and LIN E) are used to match the strength of the input signal to the requirements of the tape. If the input
signal is a little too strong these controls must be adjusted to reduce it to prevent distortion. If the signal is a little too weak, the
controls must be set to increase the preamplification for raising the signal above the tape's noise level. Of these two limits, the
distortion caused by high level inputs is used as a reference for setting the controls. Generally speaking, the shaded area at the upper
(right side ) of the V U m eters' scale indicates that distortion levels are being app roached. This area b egins at 0 VU . As the id eal is to
record the p rogra m witho ut distortion of the loud parts o r losing the purity on the q uieter parts, the record ing level must co nsider both
limits.
Choice of Tape
Most ma gnetic tape av ailable com merc ially today is clearly marked with its spec ifications, such as thickness, type of base material,
tape length (or ree l diameter) and other charac teristics.
Since TEAC open reel decks are factory adjusted for use with low-noise types of tapes as standard reference, we recommend that you
use the tape selection table printed in the Owner's Manual for selecting the tape to be used.
Tape-Judging Condition and Handling
Tape condition can be judged by appearance when w ound on the reel and viewed from the side.
1) Is it neatly wound? 2) Are there steps or irregularities in the winding? 3) Is the color of the base uniform as seen from the side? 4) Is
the tape edge smooth?
Selecting the tape and reel
For recording, new tape is not necessarily needed. If the tape is of good quality the erase head will erase the previous recording as the
new recording is made. However, avoid using tape whose coating is worn, peeled off or stretched.
If the color of the winding is different throughout the reel it is an indication that two different types of tape have
been spliced in. In some cases, the color may differ according to production lot even for the same type tape, or between opposite sides
of the wound tape.
Normal condition reel
The use of a good quality reel is an important point in preventing damage to the tape edge or uneven stretching. Always use reels of
the same diameter.
Jud ging tape condition by h ow it trav els
Tapes which sna ke up and d own betwe en the guides or ov er the he ads will inevitably lead to level fluctuation and az imuth
misalignment.
Unevenly stretched tape which travels either higher or lower than the true path of the tape will in extreme cases drift off the pinch
roller.
Snaky motio n of an uneve nly stretche d tape is indicated b y the arro ws.
Dolby Laboratories Inc. have developed an effective noise reduction system which reduces tape noise and hiss by as much as 10 dB.
This system is available from TE AC C orp. in the AN -60, AN -80, AN -180, AN-30 0 and o ther mod els. When using a Dolby Noise
Reduction Un it with a TEA C dec k, note these following points:
1. Connect the Dolby NR unit directly to the deck. All audio cables from
the amplifier or other sources are then co nnected to the Dolby N R unit.
2. Unless specifically stated otherwise in the Dolby unit's Instruction
Manual, all instructions in this manual are still applicable. The type of tape
used in reco rding will determine the B IAS and EQ switch positions.
3. Before recording, be sure to perform the Dolby calibration procedure per
the instructions in the Do lby Noise R eduction U nit's Owne r's Manual.
Playback of Dolby encoded tapes
W hen playing back a tape which was Dolby encoded on a deck which does
not have internal Do lby circuitry, a separate D olby N oise R eduction U nit is
necessary. (Diagram N)
During long periods o f use, the he ads m ay bec ome slightly magnetized . As a result, high freq uency respo nse will decrea se, noise will
develop, or in extreme cases, the high frequencies will drop-out or noise will be introduced into your valued pre-recorded tapes. To
keep your d eck o perating with its original fidelity the head s should thus b e deg aussed at least on ce for every 5 0 hours of use, with i.e.,
TE AC mo del E-l Head De magnetizer. Places specified for degaussing include each head, capstan shaft and guide post. Before
proceeding with the following steps move all the pre-recorded tapes sufficiently away from the degaussing area.
1. Turn OF F power to the deck.
2. Slide the switch of E -l ON, bring the tip close to the head and slowly mo ve it up and d own four o r five times.
3. Slowly draw it away from the head.
4. After finishing all points, turn OFF power to the demagnetizer only after it has been drawn at least 12 inches (30 cm) away from the
heads.
After p rolonged use the p inch ro ller will accumulate a film of oxide . Use only Fluid "B " from the T EA C T Z-26 1 kit as it is esp ecially
formulated for cleaning rubber surfaces. Do not use chlorothane as it will cause deterioration of the rubber roller.
Note: The newer tape formulations leave a gray or white residue which is difficult to detect. Regular cleaning schedules should be
established rather than relying on observation.
Care of the wooden cabinet
Ordinary furniture cleaner and polish can be used to maintain the attractive finish.
Cleaning the Faceplate.
A soft cloth and mild cleaning fluids (non-ab rasive) can be used to restore the luster of the faceplate. An oil-damped cloth will also
give good results, but take care not to get oil on the tape path components such as the pinch roller, capstan, etc.
Basic Trouble-shooting Chart
Basic troub le-shoo ting of an open reel tap e dec k is similar to trouble-shoo ting any other electrical or electro nic equipment. Always
check the most obvious possible causes first including such things as: power cord, fuse, switch and control setting or position, proper
co nnectio ns to the desired inpu t and output signal, etc. Consult your O wner's Manua l for the correct operating procedure and
instructions.
Many of the most common problems are listed in the chart below.
Tape T ransport
VU meter lamps do not illuminate when power Power cord connected, fuse ok?
SW is turned on
No tape motion Is tape properly threaded and shut-off arm held in proper position?
Tape rubbing reel flanges Is reel properly seated, reel adap tor spacer installed o r remove d per instructions,
tape in good condition?
Playback Operation
No sound . VU M eter shows normal indication. Are connections between tape deck and amplifier properly made?
No sound, no meter indication Check co nnections and switch settings per pro cedure in O wner's M anual.
W as tape actually recorded? Try another tape.
Poor sound q uality Are heads clean? Is the tape in good condition and properly recorded?
Recording
Does not Reco rd Check switch settings and connection per Recording proc ed ure in the Owner's
Manual.
Does not Reco rd, no audio at tape monitor but Record m ode switches ON, tape in motion, heads clean?
OK at SOURCE
Monitored sound is poor, distorted, noisy, etc. Are Input levels properly set, BIAS/EQ Switches in correct position for the type
of tape you are using?
Heads clean and demagnetized, tape in good condition?
Did you follo w correct R ecording procedure give n in Owner's M anual?
Tape Loading and Erasing
TEAC's "QUIK-LOK" reel holders
Always secure these reel holders before operating the deck to assure
adequate, solid support for the tape reels. Install the clamp adaptors for
10% " reels (when required) to the reel table before mounting the large
reels. Follow the procedures below for mounting 7" reels or the adaptors
onto the deck. Numbers given refer to the illustration.
A) Rotate sections 2 and 1 of the reel shaft fully counterclockwise.
B) P lace the reel on to the reel shaft while slowly ro tating the re el CC W to
keep both tab sets in line.
C) When the reel is firmly seated on the reel table, turn sections 1 and 2
fully clockwise to secure the reel firmly in place. The tabs on section 2 of
the shaft should be ce ntered betwe en the slo ts on the reel.
1) turn the adaptor while ho lding the spacer until the ears of the spacer match the cut-outs at the back surface of the ad aptor 2) lift
spacer o ff of the adaptor 3 ) keep the spacer for future use with metal reels.
Bulk erasure: TEA C's M ode l E-2 B ulk T ape Eraser (or its equiva lent)
will quickly erase the entire tape in a few sec onds. This is the only
satisfactory way to erase a previously recorded ½ or full track tape to
prevent undesirable "cross-talk" or chatter from the former material. For
com plete d irections on ho w to use , consu lt the instructio n supp lied with
the Bulk Eraser.
Lubrication and Optional Accessories
Use TE AC TZ -255 oil or equivalent.
Lubricate points listed below at every 1,000 hours of ope ration o r once a year if equip ment is infreque ntly used.
CAPSTA N SHA FT : Rem ove the dust cove r by turning it counterclo ckwise with fingers, apply approxim ately 2 d rops of oil to the oil-
cham ber felt.
PINC H RO LLER SHA FT: U nscrew the cap with fingers, apply one drop o f oil to the shaft bearing.
CAUT ION: Do not apply excessive quantities of oil, over lubrication can be a source of difficulty. Do not apply oil to any rubber
parts. Should oil be spilled onto rubber parts, remove immediately with TEAC rubber cleaning fluid.
Lubrication should be accomplished immediately after use while equipment is still warm.
After applying lubricant, leave tape deck in horizontal position for 1—2 hours until oil is thoroughly absorbed.
Optional Accessories
MC-106L RE-1002 RE-711
Dynamic 10-1/2" Metal Reel 7 inch Metal Reel
Microphone (small hub)
TEAC,
The leader. Always has been.
TEAC CO RPOR ATION: 3-7-3, Naka-cho, M usashino, Tokyo, Japan Phone: (0422) 53-1111
TEAC CO RPOR ATION OF AM ERICA: 7733 Telegraph R oad, Montebello, California 90640 Phone: (213) 726-0303
TEAC AU STRALIA P TY.,LTD.: 165 Gladstone Street, South M elbourne, Victoria 3205, Australia Phone: 699-6000
PRINTED IN J A P A N • O 5 8 O K 4 • D -2 2 2 3 A M