Alesis M20 User Manual
ALESIS M20
P
ROFESSIONAL 20-BIT DIGITAL
RECORDER
OWNER’S MANUAL
FIRST EDITION VERSION 1.06
PPLIES TO OPERATING SOFTWARE VERSION 1.11
A
NCLUDES SOFTWARE VERSION 2.10 ADDENDUM
I
1999 ALESIS CORPORATION
ALESIS M20 REFERENCE MANUAL 1.06
TABLE OF CONTENTS
Important Safety Instructions and Compliance Notices ...................................... vii
Safety symbols used in this product................................................................................................ vii
Please follow these precautions when using this product: ............................................................ vii
Instructions de Sécurité Importantes.................................................................................................ix
Symboles utilisés dans ce produit......................................................................................................ix
Beim Benutzen dieses Produktes beachten Sie bitte die folgenden Sicherheitshinweise: ..............x
Information to the User for Class A Digital Device (FCC Part 15, Class A)................................... xi
CE Declaration of Conformity ...........................................................................................................xii
Overview, Setup, and Basics..............................................................................1
1.1 M20 Highlights .............................................................................................................................. 1
1.2 Unpacking and Inspection............................................................................................................2
1.3 AC Power Hookup........................................................................................................................ 2
1.4 Line Conditioners and Protectors................................................................................................. 3
1.5 About Audio Cables......................................................................................................................3
1.6 Basic Audio Hookup.....................................................................................................................4
1.7 Use the Right Tape......................................................................................................................... 4
1.8 Preparing the Tape Prior to Use...................................................................................................4
1.9 Eject Tape Properly........................................................................................................................4
1.10 Backup..........................................................................................................................................4
1.11 Operating Environment .............................................................................................................. 5
1.12 Avoid Electromagnetic Interference........................................................................................... 5
Control and Connector Basics ............................................................................1
2.1 About the Front Panel ...................................................................................................................1
2.2 About the Rear Panel.....................................................................................................................3
2.2a Punch Footswitch...........................................................................................................3
2.2b Locate/Play or LRC Remote Control Jack...................................................................3
2.2c Analog Inputs and Outputs...........................................................................................3
2.2d Time Code In and Out...................................................................................................3
2.2e Word Clock In and Out .................................................................................................3
2.2f ADAT Optical In and Out..............................................................................................3
2.2g Video In and Thru..........................................................................................................4
2.2h ADAT Sync In and Out................................................................................................. 4
2.2i MIDI In and Out ............................................................................................................. 4
2.2j RS-422 In (Sony 9-Pin).....................................................................................................4
2.2k Meter Bridge/Remote Panel Out..................................................................................4
2.2l Power............................................................................................................................... 4
Editing M20 Operating Parameters....................................................................1
3.1 The Keypad.................................................................................................................................... 1
3.1a 0 through 9 buttons........................................................................................................1
3.1b Up Arrow/Yes/Upper Case......................................................................................... 1
3.1c Down Arrow/No/Lower Case.....................................................................................1
3.1d Cursor Left.....................................................................................................................1
3.1e Cursor Right ...................................................................................................................1
3.1f Enter/Name.................................................................................................................... 2
3.1g Selecting Pages...............................................................................................................3
3.1h Selecting Page Parameters.............................................................................................3
3.1i Entering Parameter Values.............................................................................................3
3.2 The Edit Button.............................................................................................................................. 4
ALESIS M20 REFERENCE MANUAL 1.06 i
Table of Contents
3.3 Editing Conventions...................................................................................................................... 4
Tape Formatting...............................................................................................1
4.1 Sample Rate Selection....................................................................................................................2
4.1a Pull-up and Pull-down Sample Rate Selection ............................................................3
4.2 Word Length Selection..................................................................................................................3
4.3 Format a New Tape.......................................................................................................................4
4.4 Record Tracks While Formatting.................................................................................................. 4
4.5 Extend a Partially-Formatted Tape..............................................................................................5
4.6 End Formatting..............................................................................................................................5
4.7 Certify Tape Format ......................................................................................................................5
4.8 Reformatting: Caution!..................................................................................................................5
4.9 Lock Out Formatting (Safe Mode).................................................................................................6
4.10 Bulk Erasing.................................................................................................................................6
4.11 Recording a “Benchmark” Tape................................................................................................. 6
Track Record Enabling and Monitoring ..............................................................1
5.1 Track Basics ....................................................................................................................................1
5.2 Track Input Enables .......................................................................................................................2
5.3 Auto Input Switch ......................................................................................................................... 2
5.4 Record Enable................................................................................................................................2
5.5 Safety Mode (All Safe) ...................................................................................................................3
5.6 Monitor Inputs (All Input)............................................................................................................3
Digital/Analog Input Selection and Routing ........................................................1
6.1 Digital Source .................................................................................................................................1
6.2 Input Select .....................................................................................................................................1
6.3 Track Output Selection..................................................................................................................2
6.4 Input Signal Routing (Analog And Digital).................................................................................2
6.4a Analog Input Routing....................................................................................................3
6.4b Digital Input Routing.....................................................................................................4
6.4c Record-Enabling the Destination Tracks......................................................................5
6.5 Aux Routing (input and output) .................................................................................................. 6
Metering 1
7.1 Meter Mode Selection....................................................................................................................1
7.1a Clearing Peaks................................................................................................................1
7.2 Meter Setup....................................................................................................................................2
Transport Controls and Basic Recording.............................................................1
8.1 About the Tape Counter................................................................................................................ 1
8.2 Stop................................................................................................................................................. 1
8.3 Play ................................................................................................................................................. 2
8.3a Play Button and Sync Status..........................................................................................2
8.4 Jog/Shuttle Wheel and Search ......................................................................................................2
8.4a Jog Mode......................................................................................................................... 2
8.4b Shuttle Mode..................................................................................................................3
8.4c Search Button ..................................................................................................................3
8.4d Search Master .................................................................................................................4
8.5 Other Transport Buttons...............................................................................................................5
8.6 Record.............................................................................................................................................6
8.6a Punching Into Record ....................................................................................................6
8.6b Punching Out of Record................................................................................................6
8.6c Record Write-Protection................................................................................................ 7
8.6d Recording with a Footswitch........................................................................................7
8.7 Rehearse Mode................................................................................................................................7
8.8 Auto Record...................................................................................................................................8
ii ALESIS M20 REFERENCE MANUAL 1.06
Table of Contents
8.8a Setting Auto Record Punch Points................................................................................8
8.8b Enable Auto Record....................................................................................................... 9
8.8c Set Auto Punch Points “On the Fly”.............................................................................9
Autolocation ....................................................................................................1
9.1 Entering, Selecting, and Editing Location Points........................................................................1
9.1A Set Locate........................................................................................................................ 1
9.1B Copy Tape Location........................................................................................................ 1
9.2 Deferred Play and Record.............................................................................................................3
9.3 Play-After-Locate (Auto Play)......................................................................................................3
9.4 Loop Between Start and End Locate Points (Auto Return)........................................................3
9.4a Setting Loop Start and End Points ................................................................................4
9.5 Set Pre-Roll.....................................................................................................................................4
9.6 Set Post-Roll ...................................................................................................................................5
9.7 Footswitch-Controlled Location................................................................................................... 6
Varispeed ........................................................................................................1
SMPTE, Sync, and Offset Functions ...................................................................1
11.1 Clock Source.................................................................................................................................1
11.2 SMPTE Rate..................................................................................................................................2
11.3 Time Code Source ........................................................................................................................2
11.3a Internal...........................................................................................................................2
11.4 Chase Reference...........................................................................................................................3
11.5 Reference Counter ....................................................................................................................... 4
11.6 SMPTE Chase...............................................................................................................................4
11.6a Set SMPTE Offset Value (Page 1)................................................................................4
11.6b Set SMPTE Chase Mode (Page 2)................................................................................5
11.6c Set Flywheel Duration (Page 3)................................................................................... 5
11.6d Park Ahead (Page 4)....................................................................................................5
11.7 Internal Generator........................................................................................................................ 6
11.7a Generator Mode (Page 1) .............................................................................................6
11.7b Time Code Start Reference (Page 2) ........................................................................... 7
11.7c ABS/Start Offset (Page 3)............................................................................................7
11.7d User Bits (Page 4, or Page 3 if the Page 2 value is TC Track)...................................8
11.8 Tape Offset...................................................................................................................................8
11.9 Track Delay ................................................................................................................................10
MIDI Functions.................................................................................................1
12.1 MIDI Device (Page 1)................................................................................................................... 1
12.2 MMC Output (Page 2).................................................................................................................1
12.3 MTC Follow Gen (Page 3)...........................................................................................................1
12.4 Send Sysex Dump? (Page 4) ........................................................................................................1
12.5 Receive Sysex Dump? (Page 5)................................................................................................... 2
12.6 Send Software? (Page 6).............................................................................................................. 2
12.7 Load Software? (Page 7) ..............................................................................................................2
Utility Menu.....................................................................................................1
13.1 Digital Out (Page 1).....................................................................................................................1
13.2 Online Source (Page 2)................................................................................................................. 1
13.2a Online Button................................................................................................................ 1
13.2b Independent Slave Mode.............................................................................................2
13.3 Online Control (Page 3)...............................................................................................................2
13.4 One-Button Record (Page 4)........................................................................................................ 2
13.5 Input Monitor (Page 5)................................................................................................................ 2
13.6 Crossfade Time (Page 6)..............................................................................................................3
13.7 Time Code Output Level (Page 7)..............................................................................................3
ALESIS M20 REFERENCE MANUAL 1.06 iii
Table of Contents
13.8 Rewind/Fast Forward TC Output (Page 8) ...............................................................................3
13.9 Unthread Timeout (Page 9) .........................................................................................................3
13.10 Search Enable (Page 10)............................................................................................................. 4
13.11 Locate Before Play (Page 11).....................................................................................................4
13.12 Mute Until Lock (Page 12).........................................................................................................4
13.13 Dynamic Punch (Page 13).......................................................................................................... 4
13.14 Track Groups (Page 14)............................................................................................................. 4
13.15 Save Data to Tape? (Page 15)....................................................................................................4
13.16 Load Data from Tape? (Page 16) ..............................................................................................5
13.17 Tape Type (Page 17)...................................................................................................................5
13.18 ID Status (Page 18)..................................................................................................................... 5
13.19 User Bits (Page 19)..................................................................................................................... 5
13.20 Error Rate (Page 20)................................................................................................................... 6
13.21 Front Panel Software Version (Page 21)................................................................................... 6
13.22 Software Version (Page 22) .......................................................................................................6
The LRC Remote Control....................................................................................1
Tutorials and Applications ................................................................................1
TUTORIAL 1: Multiple M20 Operation..............................................................................................1
Overview................................................................................................................................. 1
Synchronizing Machines ........................................................................................................ 1
Automatic ID Renumbering...................................................................................................1
Master/Slave Interaction........................................................................................................ 2
Achieving Lock .......................................................................................................................2
Independent Slave Mode........................................................................................................ 2
Formatting Multiple Tapes.................................................................................................................. 3
Master Format Enabled, Complete Format ..........................................................................3
Master Format Enabled, Format Extend ...............................................................................3
Master Format Disabled......................................................................................................... 4
Master Format Disabled, Format Extend..............................................................................4
TUTORIAL 2: Making Digital Backups..............................................................................................5
Dealing with Damaged Tape.................................................................................................6
Making a 16-bit copy from a 20-bit master...........................................................................6
TUTORIAL 3: Recording Digital Audio from Other Sources ...........................................................7
Digital Clock Considerations.................................................................................................7
TUTORIAL 4: Combining M20s and ADATs ....................................................................................8
M20 Transport Speed ............................................................................................................. 8
Sample rate vs. Pitch Control.................................................................................................8
Input Monitoring .................................................................................................................... 8
Polarity Differences ................................................................................................................ 9
TUTORIAL 5: Setting up Inputs........................................................................................................10
TUTORIAL 6: Updating M20 Software............................................................................................11
TUTORIAL 7: Using the M20 with Unbalanced Inputs and Outputs............................................12
M20 SMPTE Synchronization Overview ..............................................................1
16.1 Synchronization Basics.................................................................................................................1
Master or Slave? ......................................................................................................................1
Digital Timing Requirements.................................................................................................1
16.2 The One Clock Principle..............................................................................................................2
16.2a House Sync ...................................................................................................................2
16.2b “Genlocked” Time Code...............................................................................................2
16.3 Reference Counters vs. Clock Sources....................................................................................... 3
16.3a Location Reference........................................................................................................3
16.3b Reference Clock............................................................................................................. 3
16.3 Offsets in the M20........................................................................................................................5
iv ALESIS M20 REFERENCE MANUAL 1.06
Table of Contents
16.3a SMPTE Chase Offset.................................................................................................... 5
16.3b Internal Generator ABS Offset..................................................................................... 6
16.3c Tape Offset.................................................................................................................... 6
16.4 SMPTE Time Code Rates and Types ...........................................................................................7
16.4a Drop Frame....................................................................................................................7
16.4b Auto-detection of SMPTE Rates .................................................................................. 7
16.4c VITC (Vertical Interval Time Code) ............................................................................8
16.4d MTC (MIDI Time Code) ...............................................................................................8
Time Code Tutorial...........................................................................................1
17.1 Generating Time Code onto a VCR............................................................................................ 1
17.2 Synchronizing Without a T/C Track...........................................................................................2
17.3 Recording a Time Code Track....................................................................................................3
17.3a Recording SMPTE from ABS Time..............................................................................3
Maintenance and Troubleshooting.....................................................................5
18.1 ADAT Head Cleaning................................................................................................................. 5
18.1a Head Cleaning Cassettes (optional)............................................................................6
18.1b Manual Head and Tape Path Cleaning ......................................................................6
18.2 ADAT Head Life..........................................................................................................................7
18.2a Head Alignment...........................................................................................................7
18.3 Tape Maintenance: Safe Tape ..................................................................................................... 8
18.3a Tape Wear..................................................................................................................... 8
18.3b Care of ADAT Tapes ................................................................................................... 8
18.4 Maintenance/Service...................................................................................................................9
18.4a Exterior Cleaning.......................................................................................................... 9
18.4b Maintenance ................................................................................................................. 9
18.4d Obtaining Repair Service...........................................................................................10
M20 Hidden Functions ......................................................................................1
Power-On Button Combinations.........................................................................................................1
Miscellaneous Button Combinations .................................................................................................. 1
Advanced Functions............................................................................................................................. 3
Using The M20 Data Section Of Tape .................................................................1
General data section convention on the M20.....................................................................................1
M20 Locate Points and SMPTE Offsets .............................................................................................. 1
BRC ⇔ M20 Song Start / SMPTE Start Offset and Locate Point Map.............................................1
BRC ⇔ M20 Parameter Map...............................................................................................................2
M20 Transport & System Error Messages...........................................................1
M20 Major Feature Update: Version 2................................................................1
RS-422 (Sony 9-pin) slave operation.................................................................................................... 1
RS-422 Track Arm: On/Off.................................................................................................... 1
RS-422 Mapping: 1-2, OddEvn, (Local).................................................................................1
ID 1 offline with the CADI remote......................................................................................................2
CADI Tape and Reference Counter indications when ID 1 is offline...............................................2
Storing locate points when ID 1 is offline ...........................................................................................2
Tape TC detection in fast wind modes...............................................................................................3
Tape TC in the Tape Counter ..............................................................................................................4
Fixed mode time code generation: “TC Start Ref: Fixed”................................................................. 4
Digital Scrub: “Dig Scan: On/Off, nn dB”..........................................................................................5
I/O Card as the digital source.............................................................................................................5
SMPTE Chase with the Stop button.................................................................................................... 5
Tape TC updating when in Input mode............................................................................................. 5
Vari-Speed and Pull-Up/Down ..........................................................................................................5
ALESIS M20 REFERENCE MANUAL 1.06 v
Table of Contents
MIDI Thru.............................................................................................................................................6
New Utility page order........................................................................................................................6
CADI display changes..........................................................................................................................6
Cassette Auto-Inject ............................................................................................................................. 6
Deck Standby Mode............................................................................................................................. 7
Auto-Park After Formatting................................................................................................................7
Deferred Eject .......................................................................................................................................7
New RS-422 Device ID.........................................................................................................................7
Improved SMPTE Clock Source Recognition.....................................................................................7
Sample Rate Change During Play/Record .........................................................................................7
vi ALESIS M20 REFERENCE MANUAL 1.06
IMPORTANT SAFETY
INSTRUCTIONS AND COMPLIANCE
NOTICES
SAFETY SYMBOLS USED IN THIS PRODUCT
This symbol alerts the user that there are important operating and
maintenance instructions in the literature accompanying this unit.
This symbol warns the user of uninsulated voltage within the
unit that can cause dangerous electric shocks.
PLEASE FOLLOW THESE PRECAUTIONS WHEN USING THIS
PRODUCT
2. Keep these instructions.
3. Heed all warnings.
4. Follow all instructions.
5. Do not use this apparatus near water.
6. Clean only with a damp cloth.
7. Do not block any of the ventilation openings. Install in accordance with the
8. Do not install near any heat sources such as radiators, heat registers, stoves, or
:
1. Read these instructions.
Do not spray any liquid cleaner onto the faceplate, as this may damage the front panel
controls or cause a dangerous condition.
manufacturer's instructions.
other apparatus (including amplifiers) that produce heat.
(more on next page)
ALESIS M20 REFERENCE MANUAL 1.06 vii
Safety Notices
10. Protect the power cord from being walked on or pinched particularly at plugs,
11. Use only attachments/accessories specified by the manufacturer.
12. Use only with a cart, stand, tripod, bracket, rack, or table specified by the
9. Do not defeat the safety purpose of the polarized or grounding-type
plug. A polarized plug has two blades with one wider than the other.
A grounding-type plug has two blades and a third grounding prong.
The wide blade or the third prong is provided for your safety. When
the provided plug does not fit into your outlet, consult an electrician
for replacement of the obsolete outlet.
convenience receptacles, and the point where they exit from the apparatus.
manufacturer, or sold with the apparatus. When a cart is used, use caution when
moving the cart/apparatus combination to avoid injury from tip-over.
Alesis recommends the use of standard 19” racks designed for use with professional audio
or music equipment, and the use of rear rack rail supports or sliders. In any installation,
make sure that injury or damage will not result from cables pulling on the apparatus and
its mounting.
13. Unplug this apparatus during lightning storms or when unused for long periods
of time.
14. Refer all servicing to qualified service personnel. Servicing is
required when the apparatus has been damaged in any way,
such as when the power-supply cord or plug is damaged, liquid
has been spilled or objects have fallen into the apparatus, the
apparatus has been exposed to rain or moisture, does not
operate normally, or has been dropped.
15. This unit produces heat when operated normally. If this unit is installed in a rack, make
sure that there is proper ventilation when operated. Do not operate in an enclosed rack
with closed front and back doors. If there are other units in the rack that generate a large
amount of heat, spread them apart. Do not sandwich this product between two large
heat-producing units.
16. This product, in combination with an amplifier and headphones or speakers, may be capable of
producing sound levels that could cause permanent hearing loss. Do not operate for a long period
of time at a high volume level or at a level that is uncomfortable. If you experience any hearing
loss or ringing in the ears, you should consult an audiologist.
viii ALESIS M20 REFERENCE MANUAL 1.06
INSTRUCTIONS DE SÉCURITÉ IMPORTANTES
SYMBOLES UTILISÉS DANS CE PRODUIT
Ce symbole alèrte l’utilisateur qu’il existe des instructions de fonctionnement et de maintenance
dans la documentation jointe avec ce produit.
Ce symbole avertit l’utilisateur de la prèsence d’une tension non isolèe à l’intèrieur de l’appareil pouvant
engendrer des chocs èlectriques.
Veuillez suivre ces prècautions lors de l’utilisation de
l’appareil:
1. Lisez ces instructions.
2. Gardez ces instructions.
3. Tenez compte de tous les avertissements.
4. Suivez toutes les instructions.
5. N’utilisez pas cet allareil à proximitè de l’eau.
Safety Notices
6. Ne nettoyez qu’avec un chiffon humide. Ne pas vaporiser de liquide nettoyant sur
l’appareil, cela pourrait abîmer les contrôles de la face avant ou engendrer des conditions
dangeureuses.
7. Installez selon les recommandations du constructeur.
8. Ne pas installer à proximilè de sources de chaleur comme radiateurs, cuisinière ou autre
appareils (don’t les amplificateurs) produisant de la chaleur.
9. Ne pas enlever la prise de terre du cordon secteur. Une prise murale avec terre deux
broches et une troisièrme relièe à la terre. Cette dernière est prèsente pour votre sècuritè.
Si le cordon secteur ne rentre pas dans la prise de courant, demandez à un èlectricien
qualifiè de remplacer la prise.
10. Evitez de marcher sur le cordon secteur ou de le pincer, en particulier au niveau de la
prise, et aux endroits où il sor de l’appareil.
11. N’utilisez que des accessoires spècifiès par le constructeur.
12. N’utilisez qu’avec un stand, rack ou table conçus pour l’utilisation d’audio professionnel
ou instruments de musique. Dans toute installation, veillez de ne rien endommager à
cause de câbles qui tirent sur des appareils et leur support.
13. Dèbranchez l’appareil lors d’un orage ou lorsqu’il n’est pas utilisè pendant longtemps.
14. Faites rèparer par un personnel qualifiè. Une rèparation est nècessaire lorsque l’appareil
a ètè endommagè de quelque sorte que ce soit, par exemple losrque le cordon secteur ou
la prise sont endommagès, si du liquide a coulè ou des objets se sont introduits dans
l’appareil, si celui-ci a ètè exposè à la pluie ou à l’humiditè, ne fonctionne pas
normalement ou est tombè.
15. Cet appareil produit de la chaleur en fonctionnement normal. Si cet appareil est utilisè
dans un rack, veillez à sa bonne ventilation lors de son utilisation. Ne pas faire
fonctionner dans un rack fermè. S’il y a d’autres appareils dans le rack gènèrant
beaucoup de chaleur, èloignez les. Ne pas intercaler cet appareil entre deux appareils
produisant beaucoup de chaleur.
ALESIS M20 REFERENCE MANUAL 1.06 ix
Safety Notices
16. Ce produit, utilisè avec un amplificateur et un casque ou des enceintes, est capable de
produite des niveaux sonores pouvant engendrer une perte permanente de l’ouïe. Ne
l’utilisez pas pendant longtemps à un niveau sonore èlevè ou à un niveau non
confortable. Si vous remarquez une perte de l’ouïe ou un bourdonnement dans les
oreilles, consultez un spècialiste.
BEIM BENUTZEN DIESES PRODUKTES BEACHTEN SIE
BITTE DIE FOLGENDEN SICHERHEITSHINWEISE:
1. Lesen Sie die Hinweise.
2. Halten Sie sich an die Anleitung.
3. Beachten Sie alle Warnungen.
4. Beachten Sie alle Hinweise.
5. Bringen Sie das Gerät nie mit Wasser in Berührung.
6. Verwenden Sie zur Reinigung nur ein weiches Tuch. Sprühen Sie keine flüssiger
Reiniger auf die Oberfläche, dies könnte zur Beschädigung der Vorderseite führen und
auch weitere Schäden verursachen.
7. Halten Sie sich beim Aufbau des Gerätes an die Angaben des Herstellers.
8. Stellen Sie das Gerät nich in der Nähe von Heizkörpern, Heizungsklappen oder anderen
Wärmequellen (einschließlich Verstärkern) auf.
9. Verlegen Sie das Netzkabel des Gerätes niemals so, daß man darüber stolpern kann oder
daß es gequetscht wird.
10. Benutzen Sie nur das vom Hersteller empfohlene Zubehör.
11. Verwenden Sie ausschließlich Wagen, Ständer, Racks oder Tische, die speziell für
professionelle Audio- und Musikinstrumente geeignet sind. Achten Sie immer darauf,
daß die jeweiligen Geräte sicher installiert sind, um Schäden und Verletzungen zu
vermeiden. Wenn Sie einen Rollwagen benutzen, achten Sie darauf, das dieser nicht
umkippt, um Verletzungen auszuschließen.
12. Ziehen Sie während eines Gewitters oder wenn Sie das Gerät über einen längeren
Zeitraum nicht benutzen den Netzstecher aus der Steckdose.
13. Die Wartung sollte nur durch qualifiziertes Fachpersonal erfolgen. Die Wartung wird
notwendig, wenn das Gerät beschädigt wurde oder aber das Stromkabel oder der
Stecker, Gegenstände oder Flüssigkeit in das Gerät gelangt sind, das Gerät dem Regen
oder Feuchtigkeit ausgesetzt war und deshalb nicht mehr normal arbeitet oder
heruntergefallen ist.
14. Bei normalem Betrieb des Gerätes kommt es zu Wärmeentwicklungen. Wenn Sie das
Gerät in einem Rack eingebaut haben, sollte während des Betriebes die Zufuhr von
Kühlluft stets gewährleitstet sein. Arbeiten Sie nie bei geschlossenem Rack. Bei
mehreren Rackgeräten sollten diese mit einem geringen abstand voneinander eingebaut
werden. Stapeln Sie dieses Gerät nicht zwischen Geräten mit hoher Wärmeentwicklung.
15. Dieses Produkt kann in Verbindung mit einem Verstärker und Kopfhörern oder
Lautsprechern Lautstärkepegel erzeugen, die anhaltende Gehörschäden verursachen.
Betreiben Sie es nicht über längere Zeit mit hoher Lautstärke oder einem Pegel, der Ihnen
unangenehm is. Wenn Sie ein Nachlassen des Gehörs oder ein Klingeln in den Ohren
feststellen, sollten Sie einen Ohrenarzt aufsuchen.
x ALESIS M20 REFERENCE MANUAL 1.06
Safety Notices
INFORMATION TO THE USER FOR CLASS A DIGITAL
DEVICE (FCC PART 15, CLASS A)
This equipment has been tested and found to comply with the limits for a class A digital
device pursuant to Part 15 of the FCC Rules. These limits are designed to provide reasonable
protection against harmful interference when the equipment is operated in a commercial
environment. This equipment generates, uses and can radiate radio frequency energy and, if
not installed and used in accordance with the instructions, may cause interference to radio
communications. Operation of this equipment in a residential area is likely to cause
interference in which case the user will be required to correct the interference at his own
expense.
The user is cautioned that changes and modifications made to the equipment without the
approval of manufacturer could void the user’s authority to operate this equipment.
Use only shielded and grounded cables with this equipment to ensure compliance with FCC
Rules.
INDUSTRY CANADA (DIGITAL APPARATUS)
I
NTERFERENCE-CAUSING EQUIPMENT STANDARD
ICES-003 ISSUE 2
This Class A digital apparatus meets all requirements of the Canadian Interference-
Causing Equipment Regulations.
ALESIS M20 REFERENCE MANUAL 1.06 xi
Safety Notices
CE DECLARATION OF CONFORMITY
Manufacturer’s Name: Alesis Corporation
Manufacturer’s Address: 1633 26th Street
Santa Monica, CA 90404
USA
declares, that the product:
Product Name: M20
Product Type: Modular Digital Multitrack Recorder
conforms to the following Standards:
Application of Council Directive: 89/336/EEC; 73/23/EEC
Safety: EN 60 065
(1993) First Edition, Amendment No.1 (1994)
EMC: EN 55022:1988 Class A
IEC 801-2:1991 2nd Edition, 4kV direct,
8kV air
IEC 801-3:1984 2; 3V/m 150MHz-1GHz
IEC 801-4:1988 1st Edition 2; 1kV, 0.5kV
All tests were performed with fully-shielded
cabling.
European Contact: Sound Technology
17 Letchworth Point, Lechworth,
Hertfordshire, SG6 1ND, England.
Phone: +44.1462.480000
Fax: +44.1462.480800
April, 1998
xii ALESIS M20 REFERENCE MANUAL 1.06
OVERVIEW, SETUP, AND
The Alesis M20 is an 8-track digital tape recorder that records on S-VHS videotape
cassettes. It is compatible with the ADAT format used with several other digital recorders
(Alesis ADAT, ADAT XT, LX20, and XT20; Studer V-Eight; Fostex RD-8 and CX-8; and
Panasonic MDA-1).
1.1 M20 HIGHLIGHTS
• Direct-drive full-servo S-VHS transport, designed for continuous shuttling and heavy-
duty professional use
• Two available bit resolutions: 16-bit standard ADAT Type I, and 20-bit ADAT Type II
• 24-bit A/D and D/A converters
• +4 dBu balanced XLR and ELCO (multipin) connectors
• Selectable 16-bit dithered output for transfer to 16-bit systems
• Jog/shuttle wheel for fast navigation
• Analog Aux track for superb scrub and jog monitoring
• ADAT , SMPTE, video and word clock synchronization capabilities
• Dedicated SMPTE time code track
• Optional EC-1 8 channel AES/EBU digital audio interface
• Two custom vacuum fluorescent displays
• Extensive error reporting capability
• Optional CADI remote control
• Optional RMD remote meter display
CHAPTER 1
BASICS
ALESIS M20 REFERENCE MANUAL 1.06 1-1
Overview, Setup and Basics, Chapter 1
1.2 UNPACKING AND INSPECTION
Please retain the M20’s shipping carton, which is designed to protect the unit during
shipping, in the unlikely event that you need to return the M20 for servicing. Some carriers
have restrictions on shipping electronic equipment without the original packing.
The shipping carton contains:
§ M20 with the same serial number shown on shipping carton
§ Power Cable
§ Optical Cable
§ M20 LRC (remote control unit)
§ This instruction manual
§ Blank S-VHS ST-120 cassette
§ Alesis warranty card
In order to be advised of future updates, please register your purchase immediately by
filling out the warranty card and mailing it back to Alesis.
1.3 AC POWER HOOKUP
1 Make sure the M20 is turned off. It’s good practice not to turn on the M20 until all other
cables are hooked up.
2 Before plugging in to AC power, note that the M20’s IEC-spec AC cord (do not
substitute any other AC cord) must feed a 3-pin outlet, where the third, round pin
connects to ground. The ground connection is an important safety feature designed to
keep the chassis of electronic devices at ground potential. Unfortunately, the presence
of a third ground pin does not always indicate a properly grounded outlet; check this
with an AC line tester. If the outlet is not grounded, consult with a licensed electrician.
3 Plug the power cord’s female end into the M20’s power input socket, and the male
(plug) end into any AC power source from 90 to 250 volts, 50 or 60 Hz.
Your M20 includes the correct power cord for your country or local area. When using an
M20 abroad , use only the following alternative power cords approved for use with ADAT:
• For 90-120 VAC 50/60 Hz operation in the US, Canada and/or Japan, use Alesis
UL/CSA power cord #7-41-0001.
• For 240 VAC 50 Hz operation in England, use Alesis UK power cord #7-41-0004.
• For 220 VAC 50 Hz operation in Europe and Scandinavia, use Alesis EU power
cord #7-41-0002.
• For 240 VAC 50 Hz operation in Australia, use Alesis AS power cord #7-41-0003.
1-2 ALESIS M20 REFERENCE MANUAL 1.06
Chapter 1, Overview, Setup and Basics
Alesis cannot be responsible for problems caused by using the M20 or any
associated equipment with improper AC wiring.
1.4 LINE CONDITIONERS AND PROTECTORS
Although the M20 tolerates typical voltage variations, the AC line voltage may contain
spikes or transients that can possibly stress your gear and, over time, cause a failure. There
are three main ways to protect against this, listed in ascending order of cost and
complexity:
• Line spike/surge protectors. Relatively inexpensive, these help protect against strong
surges and spikes (they usually need to be replaced after enduring an extremely strong
spike).
• Line filters. These generally combine spike/surge protection with filters that remove
some line noise (dimmer hash, transients from other appliances, etc.).
• Uninterruptible power supply (UPS). This is the best option. A UPS provides power
even if the AC power line fails completely. Intended for computer applications, a UPS
allows an orderly shutdown in the event of a power outage. Furthermore, the isolation
it provides from the power line minimizes all forms of interference ó spikes, noise, etc.
1.5 ABOUT AUDIO CABLES
The connections between the M20 and your studio are your music’s lifeline. Use only high
quality, low-capacitance, shielded cables with a stranded (not solid) internal conductor and
low-resistance shield. Although quality cables cost more, they make a difference. When
routing cables:
• Do not bundle audio cables with AC power cords.
• Avoid running audio cables near sources of electromagnetic interference such as
transformers, monitors, computers, etc.
• Do not place cables where they can be stepped on. Stepping on a cable may not cause
immediate damage, but it can compress the insulation between the center conductor
and shield (degrading performance) or reduce the cable’s reliability.
• Avoid twisting the cable or making sharp, right angle turns.
• Never unplug a cable by pulling on the wire itself. Always unplug by firmly grasping
the plug’s body, and pulling directly outward.
• Although Alesis does not endorse any specific product, chemicals such as Tweek and
Cramolin, when applied to electrical connectors, are claimed to improve the electrical
contact between connectors.
ALESIS M20 REFERENCE MANUAL 1.06 1-3
Overview, Setup and Basics, Chapter 1
1.6 BASIC AUDIO HOOKUP
When connecting audio cables and/or turning power on and off, turn off all devices in
your system and turn down your monitor system’s volume controls.
The M20 provides 10 pairs of XLR connectors (8 pairs for audio in/out, 1 pair for the
auxiliary analog channel, and 1 pair above for SMPTE time code). The nine sets of audio
XLRs connect to your mixer’s tape or line inputs and outputs. An additional multipin
ELCO connector , wired in parallel with the 8 XLR audio pairs, can connect to a “snake”
that goes to your mixer. Several manufacturers make ADAT/M20-specific cables that break
out the ELCO connector into individual ins and outs.
1.7 USE THE RIGHT TAPE
Use only premium quality, name brand S-VHS cassettes such as Quantegy 489 DM Digital
Mastering Audio Tape, or Alesis ADAT Mastering Audio Cassettes. Other acceptable brands
include Maxell XR-S Black, JVC XZ, Sony DASV, BASF Digital Master 938, Apogee AA-40,
HHB ADAT45, and TDK SP Super Pro. The cassette shell, hubs, rollers and tape guides in SVHS cassettes are precision devices that properly handle and protect the tape within them.
Caution: Do not use VHS cassettes. While they may appear to function properly at
first, their less-than-premium formulation will decrease the reliability of
your recording. They may also shed oxide and leave behind a coating of
dirt that will interfere with future recordings, even if you switch back to
premium quality tape. Defective tape may even clog the head, requiring
service. Trust your work only to premium quality S-VHS tape.
1.8 PREPARING THE TAPE PRIOR TO USE
Fast forward and rewind all new tapes at least once from end to end before attempting to
format and record on them. This important step “unpacks” the tape properly, and leads to
far more reliable operation (this is also recommended practice for DAT tapes).
1.9 EJECT TAPE PROPERLY
After a session, eject the tape and put it in a protective case. Do not:
• Leave the tape in the M20 when power is off.
• Leave the tape halfway ejected in the well. Always remove completely after ejection.
• Eject in the middle of recorded material. Malfunctions that could possibly damage the
tape are statistically most likely to occur when inserting or ejecting a tape, so always
eject where nothing is recorded.
1.10 BACKUP
Accidents can happen ó so, like computer floppy disks and hard disks, back up your M20
tapes to another M20 or ADAT using the fiber optic digital connector (see Tutorial 2 for
step-by-step instructions on backing up M20 tapes).
1-4 ALESIS M20 REFERENCE MANUAL 1.06
Chapter 1, Overview, Setup and Basics
1.11 OPERATING ENVIRONMENT
Mount the M20 in an equipment rack (requires 4 rack spaces) or place it on a table or shelf.
Alesis advises against tilting the recorder; keep it horizontal. Also remember that heat
shortens the life of electronic equipment.
Please observe the following:
• The M20 is designed to perform properly over a range of ambient temperatures from
10° C to +40° C (50° F to 104° F), in up to 80% non-condensing humidity. These are not
absolute limits, but Alesis cannot guarantee that the M20 will meet its published specs
or remain reliable if operated outside of these ranges.
• Always allow adequate ventilation behind the M20. Do not seal any enclosure that
holds the M20. It is not necessary to leave an empty rack space above or below the
M20.
• You will need to remove the screw-on feet from the bottom of the M20 if any
equipment will be mounted directly below it.
1.12 AVOID ELECTROMAGNETIC INTERFERENCE
Like all tape machines, the M20 uses magnetic tape that can be sensitive to electromagnetic
interference. Generally this is not a problem, but avoid mounting the M20 next to devices
that generate strong magnetic fields such as power amplifiers, monitors and video display
devices, speakers, etc., and always treat your tapes with care. In particular, avoid excess
heat, cold, and humidity.
ALESIS M20 REFERENCE MANUAL 1.06 1-5
Overview, Setup and Basics, Chapter 1
Figure 1 (M20 Front Panel)
1-6 ALESIS M20 REFERENCE MANUAL 1.06
CONTROL AND CONNECTOR
2.1 ABOUT THE FRONT PANEL
Referring to Fig. 1, the front panel includes:
• S-VHS cassette door and Eject button
• Main vacuum fluorescent display (toward the center) with two sets of 10-character 7-
segment readouts. The left readout shows the current tape location. The right readout
shows information such as incoming SMPTE time, locate address, current offset, etc. A
24-character alphanumeric display above the 7-segment display shows edit location
points, pre/post-roll times, pitch value, and various messages.
• 9 function buttons (below the main display)
• 5 transport buttons
• 4 locate-related buttons
CHAPTER 2
BASICS
• Rehearse button
• Jog/shuttle wheel and search button
• 15-button numeric keypad for data entry
• 15 editing switches
• Secondary vacuum fluorescent display with VU meters for the 8 audio channels and
auxiliary track, the time code track signal, error lights, track input and record lights, and
input selection and routing indicators.
• 22 track enable and track record buttons
• 6 routing, source selection, and metering buttons
• Online/offline button
• Recessed power switch
ALESIS M20 REFERENCE MANUAL 1.06 2-1
Control and Connector Basics, Chapter 2
Figure 2 (M20 Rear Panel with optional EC-1 AES/EBU Card)
2-2 ALESIS M20 REFERENCE MANUAL 1.06
2.2 ABOUT THE REAR PANEL
Referring to Fig. 2, the rear panel includes:
2.2A PUNCH FOOTSWITCH
This allows foot-controlled punch in and out. Use a momentary footswitch, either normallyopen or normally-closed (the M20 senses the type on power-up and calibrates itself).
2.2B LOCATE/PLAY OR LRC REMOTE CONTROL JACK
This 1/4” jack accepts a momentary footswitch (normally closed or open) to allow footcontrolled location functions. It also accepts the LRC remote control (see Chapter 14) for
remote access of transport functions.
Note: If using a normally open footswitch, the footswitch and LRC remote control can be
interchanged, or used simultaneously with a Y-cord, without restarting (powering
down and powering up) the M20. However, if using a normally closed footswitch,
the M20 unit should be restarted after switching from footswitch to remote control
and vice-versa.
Chapter 2, Control and Connector Basics
2.2C ANALOG INPUTS AND OUTPUTS
18 XLR connectors carry the +4 dBu balanced analog inputs and outputs. There are 9 audio
input and output channels (channels 1 through 8 plus Aux). Channels 1 through 8 inputs and
outputs are also accessible through a multi-pin ELCO connector, which is wired in parallel
with the XLR inputs and outputs. All XLR connectors are wired with pin 2 “hot,” in
accordance with IEC standards.
2.2D TIME CODE IN AND OUT
The time code input and output use balanced XLR connectors for use with SMPTE/EBU
standard time code systems. Time code input allows the M20 to be slaved to an external
device; time code output provides timing reference to an external device.
2.2E WORD CLOCK IN AND OUT
These are BNC connector, TTL-level word clock inputs and outputs. A master word clock
signal, which the M20 can provide, allows synchronizing the audio data stream for all digital
audio devices in a system. If a master word clock signal already exists, the M20 can sync to
it.
2.2F ADAT OPTICAL IN AND OUT
The optical input and output are an industry-standard digital audio interface, pioneered by
Alesis, that carries 8 digital audio channels (with up to 24 bits of resolution) on a single fiber
optic cable. The standard cable is a 1mm diameter plastic fiber with Toslink connectors. One
1-meter cable is provided with the M20; additional cables of different lengths are available
from your dealer. Applications include digitally dubbing from one deck to another,
interfacing with hard disk recording systems and synthesizers, and feeding translators that
change the ADAT optical format to other formats.
ALESIS M20 REFERENCE MANUAL 1.06 2-3
Control and Connector Basics, Chapter 2
2.2G VIDEO IN AND THRU
The BNC connector video input (with 75 ohm termination switch) accepts composite video
as well as black burst video inputs.
2.2H ADAT SYNC IN AND OUT
These 9-pin D connectors synchronize multiple ADATs together to single-sample accuracy.
Computer interface cards with ADAT sync, such as the Alesis ADAT-PCR, allow
transferring ADAT data to and from a computer for editing with single-sample accuracy.
Interface cards without ADAT sync allow transferring ADAT data with 1/4 frame accuracy
via MIDI Time Code.
2.2I MIDI IN AND OUT
These 5-pin DIN connectors can output and/or receive MIDI Machine Control commands,
save and load sysex dumps defining the M20 status, allow for software updates via MIDI
sysex files, and output MTC (MIDI Time Code) when selected.
2.2J RS-422 IN (SONY 9-PIN)
This 9-pin D connector connects to a video editor or other controller that supports the Sony
9-pin protocol. This feature will not be operational until M20 Version 2.0 software becomes
available.
2.2K METER BRIDGE/REMOTE PANEL OUT
This RJ-45 connector connects to an optional remote controller like the Alesis CADI remote,
and/or RMD meter bridge.
2.2L POWER
The IEC-standard, grounded AC input plug accepts AC voltages from 90 to 250 volts,
eliminating the need for transformers or voltage switches.
2-4 ALESIS M20 REFERENCE MANUAL 1.06
EDITING M20 OPERATING
3.1 THE KEYPAD
The keypad block contains switches for editing the various parameters that control the M20’s
features.
3.1A 0 THROUGH 9 BUTTONS
Use the 10 numeric keys to enter number parameter values and letters for names. When
editing a parameter value, pressing a key enters its associated number. When editing a name,
pressing a key cycles through the letters indicated on the keycap (e.g., pressing 7 repeatedly
cycles through 7, s, t, u, v, 7, s, t…etc.).
3.1B UP ARROW/YES/UPPER CASE
This key:
CHAPTER 3
PARAMETERS
• Increments parameter values, as well as scrolls up through a list of parameter values.
Holding this button for 2 or more seconds increases the speed at which the values
increment. After 7 seconds, this speed increases again.
• Enters “Yes” in response to Yes/No queries.
• In a sign (polarity) field, selects the positive (+) sign.
• In a name field, changes lower case letters to UPPER CASE.
3.1C DOWN ARROW/NO/LOWER CASE
This key:
• Decrements parameter values, as well as scrolls down through a list of parameter values.
Holding this button for 2 or more seconds increases the speed at which the values
decrement. After 7 seconds, this speed increases again.
• Enters “No” in response to Yes/No queries.
• In a sign (polarity) field, selects the negative (-) sign.
• In a name field, changes UPPER CASE letters to lower case.
3.1D CURSOR LEFT
When editing, this key positions the cursor (a single underline character, showing that a
parameter is ready for editing) under the next field to the left. (Note: It will not move across
page boundaries.)
3.1E CURSOR RIGHT
When editing, this key positions the cursor (a single underline character) under the next field
to the right. (Note: It will not move across page boundaries.)
ALESIS M20 REFERENCE MANUAL 1.06 3-1
Editing M20 Parameters, Chapter 3
3.1F ENTER/NAME
This key has two main uses:
• Speed up numeric entry by eliminating the need for “leading zeroes.” For example, the
varispeed setting is a 3-digit value. Instead of having to key in something like 0 - 0 - 9,
you can simply key in 9, then press Enter.
• Edit location point names. When the locate time is the currently selected field, pressing
the Enter/Name button positions the cursor at the first character of the name. The cursor
buttons now select individual characters within the name field or other displayed fields;
use the keypad buttons to change the character. For upper case, use the Up Arrow. For
lower case, use the Down Arrow.
To exit the name field, press the Enter/Name button again.
Using the default name list instead of entering letters individually: An additional
name editing option is available. Holding down the Name button while using the
Up/Down buttons scrolls through a default set of 16 generic names (e.g., Verse 1,
Chorus, Bridge, etc.). This list may be customized for your working style.
To customize the default set of names:
1 Select the default name to be changed.
2 Edit it.
3 To store the new name in the default name list, hold the Enter/Name button and press
the Record button.
3-2 ALESIS M20 REFERENCE MANUAL 1.06
Chapter 3, Editing M20 Parameters
3.1G SELECTING PAGES
Most buttons have at least one associated display page, which contains one or more
parameters. If there are multiple pages, the main display’s left side shows the current page
number; repeatedly pressing the associated button cycles through the pages.
Shortcut: To access a particular page directly, hold the associated button and use the keypad to enter
the desired single-digit page number.
Functions with double-digit page numbers (e.g., the Utility function) have a different access
procedure. Hold the current function button and press the 2 digits within 3 seconds of each
other. To select a single digit page number (1 through 9), press and hold the current function
button and either:
• Enter 0, then the digit; or
• Press the single digit, then the Enter button. (Note: If the Enter button is not pressed
within 3 seconds, the display reverts to its previous state.)
3.1H SELECTING PAGE PARAMETERS
To select the desired parameter for editing in multi-parameter pages, position the cursor
with the Left or Right Cursor button under the parameter value’s rightmost digit.
3.1I ENTERING PARAMETER VALUES
Entering complete values: Use the numeric keypad and enter the most significant digit first.
Enter all of a field’s digits to complete the entry. The cursor automatically advances through
the fields.
Increment/decrement a value by one: Use the keypad’s Up and Down buttons. Holding the Up
or Down button for more than 2 seconds increments (or decrements) the value continuously.
The value above the cursor will be changed. If the value goes beyond a boundary (for
example, increasing from 59 seconds to 0), the next field will be calculated automatically (in
this example, the minute field will be automatically increased).
ALESIS M20 REFERENCE MANUAL 1.06 3-3
Editing M20 Parameters, Chapter 3
3.2 THE EDIT BUTTON
The Edit button toggles the M20 in and out of Edit Mode. Enabling Edit mode (button lit)
allows editing parameter values for the functions grouped with the Edit button: Track Delay,
Tape Offset, SMPTE Chase, Internal Gen, Format, Pre-Roll, Post-Roll, Auto Return, and Auto
Record. While Edit is On, only the currently selected function’s switch will light. However,
the M20 retains the current on/off status of all switches, and these become visible after
exiting Edit mode.
Note: Don’t be confused! Editing a function does not turn it on. For example, while
editing the Post Roll value the Post Roll switch will be lit, but if the light goes out
when you leave Edit mode, Post Roll is not yet active.
If the Edit LED is not lit, pressing the various switches toggles these functions on and off.
Example: If you’ve used the Edit button to edit the amount of Tape Offset and the Edit button
is off, turning on the Tape Offset button enables the programmed amount of offset.
Pressing the Display, Pitch Value, or Utility button will also exit Edit mode and enter the
Display, Pitch, or Utility pages, respectively.
3.3 EDITING CONVENTIONS
• The rightmost 7-segment display shows locate times in hours, minutes, seconds, frames,
subframes and samples. Subframes equal 1/100th of a frame and range from 0…99. The
number of samples per subframe depends on the Tape Counter and Sample Rate settings.
If the tape counter is in ABS Time mode, there are always 15 samples per subframe in 48
kHz and 14 per subframe at 44.1 kHz. If the counter is in a SMPTE Time Code mode and
the sample rate is 48 kHz, Sample steps range from 0 - 15 for 30 frames/sec, 0 - 15 or 16 for
29.97 frames/sec, 0 - 18 for 25 frames/sec, and 0 - 19 for 24 frames/sec.
• A lit arrow above the subframe (SF) indicator indicates that there is a non-zero sample
value. To access the samples field, with the subframe field selected press the Right
Cursor button. This selects a second page that shows only the sample value.
• When editing any tape address, the cursor steps in fields (hours, minutes, seconds,
frames, subframes, and samples) instead of stepping every digit.
• When editing any tape address, entering digits with the keypad automatically advances
the cursor or selected field (using the Up/Down Arrows does not advance the field)
• When editing a field in the 7-segment display, the digit(s) of the selected (and currently
editable) field will flash.
3-4 ALESIS M20 REFERENCE MANUAL 1.06
CHAPTER 4
TAPE FORMATTING
Formatting is essential to the ADAT system. It creates a sample-accurate time reference (i.e.,
it’s accurate to 1/48,000th of a second when recording at 48 kHz) on each tape, in addition to
block ID codes, linear control track, and other essential markers. This provides tight
synchronization ó far better than SMPTE sync ó between ADAT-compatible devices, as well
as precision tape counter readings and intelligent autolocation functions.
The format process first records 15 seconds of leader (the display shows LEAd), followed by
two minutes of data (the display shows dAtA), then ABS time code starting at 00:00:00.00
and continuing to the end of the tape.
Caution: formatting a tape erases all material on all tracks. Always check that the tape is either blank
or contains unwanted material before formatting.
You can either:
• Format a tape completely before recording (recommended)
• Format while you are recording, for as long as needed
• Extend the format of an incompletely formatted tape
Before formatting a blank tape, you must select:
• The sample rate (44.1 or 48 kHz)
• The word length (20-bit for Type II tapes, or 16-bit for compatibility with Type I
ADAT and ADAT-XT tapes)
ALESIS M20 REFERENCE MANUAL 1.06 4-1
Formatting Tape, Chapter 4
4.1 SAMPLE RATE SELECTION
Choose between 44.1 kHz (CD/consumer standard) or 48 kHz (DAT/professional standard).
Here are some general hints:
• If mixing the tape through a digital mixer for a CD master, use 44.1 kHz to avoid sample
rate conversion.
• If mixing the tape through an analog mixer, use 48 kHz for slightly better high frequency
response.
• If you plan to transfer M20 tracks over to a hard disk system for editing, note that audio
recorded at 48 kHz requires about 10% more storage capacity than the equivalent audio
recorded at 44.1 kHz.
The following sample rate selection procedure assumes that Clock Source is set to INTernal.
Operation You press… You see…
Select sample rate Sample Rate
button
Sample Rate block toggles between 44.1
or 48 kHz (default) with each Sample
Rate button press
About changing sample rates: The sample rate chosen during the format process does
not have to be used during playback or recording of that particular tape; the ADAT
format always allows you to override the default sample rate from the tape. When
loading a formatted tape, the sample rate will automatically switch to the tape’s
original settings. You may change the sample rate setting to playback or record with
a different sample rate, but the sample rate indicator will flash to indicate that it is
not at the original setting. Changing the sample rate directly affects the pitch and
speed of any audio recorded.
When extending a format, the sample rate will automatically assume the existing
format’s values. There is no way to format a tape with a “44.1” marker on one
section and a “48” marker on another.
4-2 ALESIS M20 REFERENCE MANUAL 1.06
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