ALESIS MMT-8 (MT) Service Manual P/N: 8-31-0018-A ATTENTION! THIS DOCUMENT CONTAINS SENSITIVE PROPRIETARY INFORMATION. ALL RECIPIENTS MUST HAVE A CURRENT NON-DISCLOSURE AGREEMENT ON FILE WITH ALESIS, LLC. DO NOT MAKE ILLEGAL COPIES OF THIS DOCUMENT The information in this document contains privileged and confidential information. It is intended only for the use of those authorized by Alesis.
Preface This document is intended to assist the service technician in the operation, maintenance and repair of the Alesis device. Together with the User Reference Manual, this document provides a complete description of the functionality and serviceability of the Device. Any comments or suggestions you may have pertaining to the document are welcome and encouraged.
Warnings TO REDUCE THE RISK OF ELECTRIC SHOCK OR FIRE, DO NOT EXPOSE THIS PRODUCT TO WATER OR MOISTURE. The arrowhead symbol on a lightning flash inside a triangle is intended to alert the user to the presence of un-insulated "dangerous voltage" within the enclosed product which may be of sufficient magnitude to constitute a risk of electric shock to persons.
Safety Instructions Carefully read the applicable items of the operating instructions and these safety suggestions before using this product. Use extra care to follow the warnings written on the product itself and in the operating instructions. Keep the operating instructions and safety suggestions for reference in the future. 1. Power Source. The product should only be connected to a power supply which is described either in the operating instructions or in markings on the product. 2.
General Troubleshooting While this manual assumes that the reader has a fundamental understanding of electronics and basic troubleshooting techniques, a review of some of the techniques used by our staff may help. 1. Visual Inspection - A short visual inspection of the unit under test will often yield results without the need of complex signal analysis (burnt, or loose components are a dead giveaway). 2.
TABLE OF CONTENTS PREFACE ......................................................................................................... ii READ THIS! ...................................................................................................... ii WARNINGS .......................................................................................................iii SAFETY SUGGESTIONS..................................................................................iv General Troubleshooting .................
1.00 General Description The MMT-8 MultiTrack Recorders power lies mainly in the sophistication of it's software. The most powerful troubleshooting tools available to the technician are the a good working knowledge of the MMT-8's operation and the software history in section X.X. Most problems with the MMT-8 arise from either user error, or older software. The hardware is very simple and should normally prove to be problem to troubleshoot.
This circuit uses the differential between raw +10V, and regulated +5V, to generate the required signals for system RESET. This is necessary due to fact that the system MUST be in a reset state while powering down, otherwise, random noise on the 8031 data, and address, busses could corrupt SRAM data, and destroy any hope that the battery backup will work. R11, R12, and the 5.
The tape output hardware is simply the 8031 output port P3.2 (pin 12), a pullup resistor (R40), and a voltage divider (R39 and R39) for achieving a line level output. The output during tape save or type sync out applications, will appear as a .5V pulse train, but only if the tape out is NOT connected to a deck (the decks A.C. coupling will distort the output). While we have heard many complaints regarding tape back up, we have actually found very few actual tape failures.
9.00 Troubleshooting Alesis MMT-8 Service Manual 1.
10.00 Software History DATE VERSION COMMENTS 11/1/87 1.02 First production release 12/1/87 1.03 1) Fixes tape sync output so that when a part or song loops, a clock output pulse isn't skipped. 2) Outputs MIDI controller 64 (sustain pedal) at value 0 (off) once for each MIDI channel whenever a part or song is stopped so as to stop synths from sustaining.
3/8/89 1.09 1) If a song was stopped and continued within the first part of the song, the MIDI output of the sequence would not always be in sync with the click, MIDI clock, and display. This is now fixed. 2) If a track of a song was shifted by 2 or more 384th notes, and one or more of the parts of the song was 1 beat in length, the first occurrence of a 1 beat part would be played twice, causing that track to be delayed by 1 beat. This is now fixed.
6) In step edit mode, changing the start time of a sysex event forward would cause a lock up and often complete memory dump. This is now fixed. 10/31/90 1.11 1) If an empty part is selected, Edit mode should not be able to be entered. However, if an empty part is played, it is possible to enter Edit mode, stop playing, and then insert events which will corrupt data. Now, Edit mode cannot be selected when playing an empty part.
11.00 MIDI Implementation The following information is provided as a guide for programmers wishing to modify the data received via MIDI from the MMT-8 for the purpose of interchanging parts from separate block dumps, modification of part names, MIDI channel assignments, etc. Great care must be taken to insure that all modified addresses are valid, since one incorrect value (the length of a part, for example) could result in all data being lost in the MMT-8.
000H 001H 002H 003H 004H 005H " 0C6H 0C7H 0C8H-0CEH 0CFH 0D0H 0D1H-0D2H 0D3H 0D4H 0D5H-101H 102H 103H 104H 105H 106H 107H " 1C8H 1C9H 1CAH-1FFH 200H-? MSB of absolute pointer to part 00 LSB of absolute pointer to part 00 MSB of absolute pointer to part 01 LSB of absolute pointer to part 01 MSB of absolute pointer to part 02 LSB of absolute pointer to part 02 " " " " MSB of absolute pointer to part 99 LSB of absolute pointer to part 99 DON'T ALTER LSB of absolute pointer to 1st byte past SONG 99 data (start
PART DATA FORMAT The following is the format of each part, starting with the address pointed to byte the absolute pointer to the part (offset by 400H): 00H 01H 02H 03H 04H 05H 06H 07H 08H 09H 0AH 0BH 0CH 0DH 0EH 0FH 10H 11H 12H 13H 14H 15H 16H 17H 18H 19H 1AH 1BH 1CH-29H 2AH-? ?-? LSB of number of bytes in part, including header. MSB of number of bytes in part, including header.
Each data event within a track consists of either 7 or 5 bytes, depending on whether or not other events exists on that same clock step.
00000000 not used After touch change format: 01111011 1vvvvvvv 0000cccc 00000000 00000000 After touch flag (123) After touch amount 0-127 MIDI channel number 0-15 not used not used Pitch bend format: 01111100 10000000 0000cccc 0aaaaaaa 0bbbbbbb Pitch bend flag (124) not used MIDI channel number 0-15 Pitch bend lsb Pitch bend msb Sysex format: 01111101 1vvvvvvv bccccccc 00000000 deeeeeee Sysex flag (125) sysex byte 0-127 b=1=EOX, b=0 then c=sysex byte not used d=1=EOX, d=0 then e=sysex byte A sysex m
SONG DATA FORMAT The following is the format of each song, starting with the address pointed to by the absolute pointer to the part (offset by 400H): 00H 01H 02H 03H-10H 11H 12H 13H 14H 15H xxH LSB of number of bytes in song, including header. MSB of number of bytes in song, including header. Tempo of song, in BPM 14 digit ASCII name of song Step 1 part number (00-99) Step 1 play tracks (bit 0=track 1, bit 7=track 8; 0=off, 1=on) Step 2 part number Step 2 play tracks etc....
ALESIS MMT-8 (MT) SCHEMATIC AND PCB FILES Confidential Alesis Service Manual 8-31-0018-A
ALESIS MMT-8 (MT) ECN HISTORY Confidential Alesis Service Manual 8-31-0018-A
ALESIS MMT-8 (MT) BOM Confidential Alesis Service Manual 8-31-0018-A
12.00 Service Parts List GROUP CAB CAB CAP CAP CAP CAP CER CER CON CON CON FIL HDR HDR HDW HDW HDW HDW IC IC IC IC IC IC IC IC IC IC IC IC IC JAC LCD LED LIT ME ME ME ME ME ME ME ME ME PCB PLS DESCRIPTION 14 PIN DIL 7 0.1 CTR 16 PIN DIL 7 0.1 CTR 0.1 MF CERDISC 1000 MF ELEC 2200 MF ELEC 4.7 MF ELEC 150 PF CERDISC 20 PF CERDISC 5 PIN DIN JACK 3.5mm JACK (P2) 3.5mm BAR JACK (P3) 0.1 MF FILM 14 PIN DIL 0.1 CTR 16 PIN DIL 0.
PLS PLS PLS PLS PLS PLS PLS RES RES RES RES RES RES RES RES RES RES RES RES RES RES RES RES RES RUB RUB RUB SWT FLIP-UP PANEL (BLK) CASE BOTTOM LCD BEZEL ALPHA SWITCH CAP FLIP-UP CHART TOP FLIP-UP CHART BOT REAR PANEL OVERLAY 100 1/8W 5% 1K 1/8W 5% 10K 1/8W 5% 100K 1/8W 5% 1.2K 1/8W 5% 1.5M 1/8W 5% 2K 1/8W 5% 220 1/8W 5% 2.2K 1/8W 5% 3.3M 1/8W 5% 470 1/8W 5% 4.
13.00 Service Manual History 7/21/94 V1.
INDEX Alesis MMT-8 Service Manual 1.
NOTES Alesis MMT-8 Service Manual 1.
