Tascam Da-78hr Technical Documentation Manual

							Technical Documentation
DA-78HR
The DTRS format has long been respected as the most reliable format in digital recording, and now the D TRS format is leading the way into high resolution 24 bitrecording.  The DA -78HR works with 16 bit D TRS machines, using the same D TRS Sync line for sample accurate lock plus the abilit y to read and write the older 16 bit format.  Howev er, the DA -78HR offers the ability to write 8 tr acks of 24 bit audio to tape in the HR format, built in SMPTE synchronization, MIDI ports for MTC and MMC, plus a built -in 8 channel digital  mixer for internal bounces or monitor mix gener ation.
                                       7733 Telegraph R oad    •   Montebello , CA 90640    •   (323) 726-0303    •   http://www .tascam.comAll features and specifications are subject to change without notice.  C\
ontact y our local TASCAM representativ e for the latest information.
The DA-78HRs high audio qualit y, long record time, ruggedreliabilit y, built -in time code capabilities, built -in MIDI capabilities, and affordable price combine into a product that can handle numerous situations.
Personal and Project StudiosMaximum features, minimum hassle.  The DA -78HR bringsDTRS tape into 24 bit audio , offering the very best sound quality available toda y.  New features lik e built in MIDI ports and SMPTE synchronization giv es you the abilit y to chase othertape machines (analog or digital), and the abilit y to work withsequencers and digital consoles.  For the ultimate cost effectiveflexibility without ha ving to locate additional accessories, the DA-78HR is the best digital tape machine for the mark et.
Live Performance and RecordingIn live performance, there is no tak e 2.  Whether you are using the DA-78HR to play some additional backing tr acks or recording the performance liv e, you can count on the DA -78HR to get it right the first time.  With 108 minutes of record time on a single tape, you can put a whole liv e song set on a single tape; no need to stop ev erything so you can switch tapes.
Audio for Video on a BudgetFor an yone trying to mak e music for television or film, theDTRS format is the de-facto standard format for tr ansfersand many stages of recording.  The synchronization featureswill allow y ou to chase another audio machine, or a video deck.  Again, the 108 minute record time w as maintained for the new 24 bit recording mode, allowing 1 hour reels to be stored on a tape, along with reference tones and the independent subcode time code track.  More advanced video applications will wanta DA-98HR, which adds 9 pin control, blackburst resolve, and built in bit split for higher resolution audio recording.
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• R ecords 8 tr acks of 24 Bit A udio To Hi8 T apes
• 24 Bit A/D and D/A Con verters
• >104dB Dynamic R ange
• 108 Minutes of R ecord Time on 120 Hi8 T ape
• SMPTE Time Code Gener ation and Chasing
• Gener ates MIDI Time Code
• R esponds to MIDI Machine Control
• R eads and W rites 16 and 24 Bit D TRS Tapes
• 16 Machine Sample Accur ate Lock with DTRS Sync
• Balanced DB25 & Unbalanced RCA Analog I/O
• TDIF Digital I/O & SPDIF Digital I/O
• W ord S ync In/Out/Thru
• T rack Slip from -200 to +7200 Samples
•  Built -In 8 Channel Digital Mix er
PRODUCT OVERVIEW
APPLICATIONSSPECIFICATIONS
Specifications:Format:R ecording Method:Tracking Method:Maximum R ecord Time:Time to Play from Stop:Shuttle Speeds:Varispeed:Subcode:SMPTE Fr ame Rates:
Error Correction:
FrequencySignal to Noise R atio:Total Harmonic Distortion:Channel Separ ation:
SamplingRecording R esolution:Reference Lev el:Crossfade Time:Track Dela y:Word S ync Source:A/D Con verters:D/A Con verters:
Analog
Analog Outputs:
Digital I/O:R emote/S ync:Time Code In:Time Code Out:Word S ync In/Thru:Word S ync Out:MIDI I/OPunch In P ort:
Dimensions:Weight:Power R equirements:
Power ConsumptionElectromagnetic En vironment:
DTRS and D TRS-HRRotary Head / Helical ScanATF (A utomatic T rack Finding)108 min (using P6-120 tape)< 2 seconds8x, 4x, 2x, 1x, 0.5x, 0.25x± 6%Independent ABS and SMPTE T C30fps, 30dfps, 29.97fps, 29.97dfps, 25fps, 24fps Double-encoded Reed-Solomon code
20Hz -20k>104dB (HR), >100dB (Standard)
						

							DA-78HR Technical Documentation
                                       7733 Telegraph R oad    •   Montebello , CA 90640    •   (323) 726-0303    •   http://www .tascam.comAll features and specifications are subject to change without notice.  C\
ontact y our local TASCAM representativ e for the latest information.
Page 2 of 3DA -78HR_TECHDOC.pdf032500
DTRS HISTORY
Ever since the introduction of the DA -88 in 1992, users of all levels ha ve been using D TRS machines to create, mix, and transfer their tr acks at home and between studios.  The DTRS standard has become renowned for top qualit y sound, top notch reliability, and the fastest tr ansport and machine lock in the business.
The DA-88but since it w as so full featured, it also found its w ay into 
major television and motion picture studios.  The D TRS format has long been the standard format to move audiofrom one studio to the next, due to the affordable nature of the machine and media, as well as the high audio qualit y.  In addition, a number of studios ha ve been using DA -88s to expand their tr ack count by having the DA -88 chase analog machines, or other digital formats.
With the the DTRS machines added some new features lik e a digital patchbay, test tone oscillators, and an ev en faster transport than the original DA -88.  Still, the DA-88 had made such an indelible mark on the industry that its production was continued b y popular demand into the year 2000.
The DA -78HRof its heritage, continuing the tr aditions established andattested to over the y ears at a new standard - 24 bit.
All in all,the most flexibilit y, and tried and true reliabilit y that has been proven for almost a decade.  
THE 24 BIT ACHIEVEMENTBACKWARDS COMPATIBILITY
When the 24 bit D TRS format was announced, most userswere curious about how we did it.  24 bit audio requires
50% more data than the original 16 bit format, y et theDA-78HR didnt cut back on tr acks or record time.  Manyassumed that the 24 bit format would ha ve been lessreliable since more information is written in a smaller space.  W ell, actually the 24 bit format is ev en morereliable.  Heres why:
Whenwriting a bunch of ones and z eros on a piece of paper.  Allthe data passes through an encoder and decoder (codec) when going to and coming from tape.  The coding processutilizes a lossless algorithm allowing a larger amount of data to be stored in the same amount of space.
The original D TRS 8-10 Modulation Principle used b y most all DAT recorders.  This format has been around for almost two decades; more efficient encoding schemes ha ve been dev eloped over time.
High Length Limited) codec commonly used in hard driv e and DVD technologies.  This format is 66% more space efficient than the codec used in the original DTRS machines.  Since only 50% more data was needed to store the audio itself , the other 16% was dedicated to additional data v erification beyond the original D TRS machine.  
So, the 24The write area is actually about the same siz e.  The 24 bit machine utilizes a better codec which offers more efficient use of the space, as well as increased reliabilit y through more accurate data verification processes.
When the high resolution machines were designed, theability to work with the original 16 bit machines lik e 
DA-38s, DA -88s, and DA -98s was a high priorit y.  
Sync ChainHigh resolution D TRS machines use the same D TRSSync line that the previous machines used.  So , you can lock an y combination of 16 bit machines with24 bit machines sample accur ately in 2 seconds or less.
Audio I/OThe new high resolution DTRS machines use the sameDB25 plugs for balanced audio , and TDIF lines for transfers and integr ation into digital studios.  This means if you are trading out 16 bit machines for 24 bitmachines, there are no new cabling requirements.  
Tape FormatThe DA-78HR can read and write 16 bit format tapes,allowing HR users to seamlessly work with owners ofolder DTRS machines.  Howev er, 24 bit tapes created on a high resolution D TRS machine will only work on other high resolution D TRS machines.
Time Code TrackIn addition to the 8 tracks of audio, DTRS machines can handle two separ ate time tracks in subcode of thetape.  One of the tr acks is the tapes absolute time, and the other is an independent SMPTE time code track.  The high resolution D TRS machines can readand write this SMPTE time code tr ack in both 16 bit and 24 bit format, so you can continue working thesame way y ou are used to working.
TASCAMs DA-88, the original DTRS format recorder 
						

							DA-78HR Technical Documentation
                                       7733 Telegraph R oad    •   Montebello , CA 90640    •   (323) 726-0303    •   http://www .tascam.comAll features and specifications are subject to change without notice.  C\
ontact y our local TASCAM representativ e for the latest information.
Page 3 of 3DA -78HR_TECHDOC.pdf032500
FRONT AND BACK PANELS
START-UP MESSAGE
The analog DB25 pinout on the DA -78HR is the exact same as on the other DTRS machines.  While these cables arereadily available in y our local retail outlets, the pinout islisted here for users wishing to mak e custom cables andsnakes.
G = GroundH = Hot (+)C = Cold (-)
The DA -78HR displa ys TASCAM HR across the meterswhen it first boots up .  For users who w ant to customiz etheir recorder, this message can be changed to displa yyour name, the name of y our studio, or anything else.
1) Turn the power on.
2) Press SHIF T so the SHIFT LED lights
3) Press HR MODE and MENU  displays mAintn2.
4) Press SUB MENU to adv ance  will display 1. T (T will scroll through the meters.)
5) Press the UP and DOWN arrows to  (Some letters cannot be displayed in the counter, but  will show up in the meters.)
6) Press SHIF T and UP
7) Select End from the char acters   Advancing one more time will displa y PrEViEw in the   counter as your new message scrolls.  
8) Press SHIFT
ANALOG DB25 PINOUT
GCHGCHGCHGCHGCHGCHGCHG
131
2514
CH12345678