Mackie d8b v3, DIGITAL 8-BUS Service Manual
56 input, fully-automated digital mixing console.
This file contains all 110 pages of 8.5" x 11" (to make it easier to print out)
D8B
HOME
DIGITAL 8•BUS
™
SERVICE MANUAL
©1999 Mackie Designs Inc.
#820-182-00
C AU TIO N
g
g
g
g
g
g
AVIS
RISK OF ELECTRIC SHOCK
DO NOT OPEN
RISQUE DE CHOC ELECTRIQUE
NE PAS OUVRIR
CAUTION: TO REDU CE THE RISK O F
ELECTRIC SHOCK DO NOT REMOVE
THE COVER (OR BACK)
NO US ER SERVICEAB LE PAR TS INS IDE
R EF E R S ER V IC IN G T O Q U AL IFIE D
PERSONNEL
W ARNING: TO RE DUCE THE RISK OF
FIRE OR E LEC TRIC SH OC K, DO NO T
EXPOSE THIS PROD UCT TO RAIN OR
MOISTURE
TO PREVENT ELECTRIC SHOCK, DO
NOT USE THIS POLARIZED PLUG W ITH
AN EXTENSION CORD, RECEPTACLE OR
OTHER OUTLET UNLESS THE BLADES
CAN BE FULLY INSERTED TO PREVENT
BLADE EXPOSURE.
ATTENTION: POUR EVITER LES
RISQUES DE C HOC ELECTRIQUE, NE
PAS ENLEVER LE COUVERCLE. AUCUN
ENTRETIEN DE PIECES INTERIEURES
PAR L'USAGER. CONFIER L'ENTRETIEN
A U P E R S O N N E L QU A L IF IE .
A VIS :P O U R EV IT ER L ES R IS Q UE S
D'INCENDIE OU D'ELECTROCUTION,
N'EXPOSEZ PAS CET ARTICLE A LA
PLUIE O U A L'HUM IDITE.
POUR PREVENIR LES CHOCS
ELE CTRIQ UES N E PA S UTILISER C ETTE
FICHE POLARISEE AVEC UN
PROLONG ATEUR , UN PR ISE DE
COUR ANT OU UNE AUTRE SORTIE DE
COURANT, SAUF SI LES LAMES
PEUVENT ETRE INSEREES A FOND
SANS LAISSER A UCUNE PARTIE A
DECOUVERT.
This apparatus does not exceed the Class A/Class B (whichever is applicable) lim its for radio
noise emissions from di
ital apparatus as set out in the radio interference regulations o f th e
Cana dia n De partment of Com m unica tions.
ATTENTION :Le présent appareil numérique n'ém et p as de bruits radioélectriques dépassant
las lim ites applicables aux appareils num ériques de c lass A /de class B (selon le cas) prescrites
dans le ré
le m e n t s ur le b ro u illage radioélectrique édicté par les ministere des com m unications
du Ca nada.
This equipm ent has been tested and found to com ply with the lim its for a Class A di
device, pursuant to part 15 of the FCC rules. These lim its are desi
protection a
environm ent. This equipm ent
ainst harm ful interference when the equipm ent is operated in a com mercial
enerates, uses, and can radiate radio energy a nd, if no t
ned to provide reasonable
ital
installed properly and used in acco rdance w ith the ins truction m anual, m ay ca use harm ful
int e rfe re n ce to r ad io c om m u nic a tio ns . O p e ra tio n of th is e q uip m e n t in a r es id e ntia l a r ea is lik ely
to c au s e h a rm f ul in te rf er e nc e i n w hic h c a se th e us e r w ill be r e qu ire d to co r re c t th e inte rf e re nc e
at his own expense.
The lightning flash with arrowhead symbol within an equilateral
triangle is intended to alert the user to the presence of uninsulated
"dangerous voltage" within the product's enclosure, that may be
of sufficient magnitude to constitute a risk of electric shock to persons.
Le symbole éclair avec point de flèche à l'intérieur d'un triangle
équilatéral est utilisé pour alerter l'utilisateur de la présence à
l'intérieur du coffret de "voltage dangereux" non isolé d'ampleur
suffisante pour constituer un risque d'éléctrocution.
2
The exclamation point within an equilateral triangle is intended to
alert the user of the presence of important operating and maintenance
(servicing) instructions in the literature accompanying the appliance.
Le point d'exclamation à l'intérieur d'un triangle équilatéral est
employé pour alerter les utilisateurs de la présence d'instructions
importantes pour le fonctionnement et l'entretien (service) dans le
livret d'instruction accompagnant l'appareil.
WARNING
Service on the d8b must only be
undertaken by experienced service
technicians.
! SMD !
The d8b makes extensive use of
surface mount components.
Servicing technicians should have the
tools, experience and patience to perform
surface mount rework.
The d8b contains components that
may be damaged by elecrostatic
discharge. All standard ESD
precautions must be taken when
! ESD !
servicing.
Additional Safety Information
Mackie Designs’ Digital 8•Bus has been tested and conforms to the following standards
and directives of the European Council:
73/23/EEC Low Voltage Directive with amendments
91/263/EEC, 89/392/EEC, and 89/336/EEC
89/336/EEC EMC Directive
IEC 950(1991)/EN60950:1992 Electrical Safety Requirements
EN55103-1 and EN55103-2 Residential (E1) and Commercial (E2) Environments
Note: The following notice concerns the lithium battery located on the motherboard
inside the Remote CPU.
CAUTION: DANGER OF EXPLOSION IF BATTERY IS INCORRECTLY REPLACED. REPLACE ONLY
WITH THE SAME OR EQUIVALENT TYPE RECOMMENDED BY THE MANUFACTURER. DISPOSE OF
USED BATTERIES ACCORDING TO THE MANUFACTURER’S INSTRUCTIONS.
ATTENTION: IL Y A DANGER D’EXPLOSION S’IL Y A REMPLACEMENT INCORRECT DE LA
BATTERIE, REMPLACER UNIQUEMENT AVEC UNE BATTERIE DU MEME TYPE OU D’UN TYPE
ÉQUIVALENT RECOMMANDÉ PAR LE CONSTRUCTEUR. METTRE AU REBUT LES BATTERIES USAGÉES
CONFORMÉMENT AUX INSTRUCTIONS DU FABRICANT.
3
CONTENTS
INTRODUCTION ......................................................................................... 5
TECHNICAL SUPPORT ................................................................................ 5
DISCLAIMER................................................................................................ 5
OVERVIEW ................................................................................................... 6
COMPUTER SYSTEM ................................................................................... 7
DSP SYSTEM ................................................................................................. 9
USER INTERFACE SYSTEM ........................................................................ 11
ANALOG SYSTEMS ................................................................................... 13
POWER....................................................................................................... 13
DSP SIGNAL FLOW, CLOCKS, MUTE ....................................................... 14
PARTS....................................................................................................... A- 1
INTEGRATED CIRCUITS AND DATA SHEETS LINKS .............................. B-1
CONNECTORS ........................................................................................ C-1
FOLD-OUT SECTIONS:
BLOCK DIAGRAMS ................................................................................. D1
EXPLODED DRAWINGS............................................................................ E1
ASSEMBLY DRAWINGS: CONSOLE ........................................................ F1
ASSEMBLY DRAWINGS: REMOTE CPU ..................................................G1
BOARD CHAPTERS (Schematics and PCB for each board)
108A Mic/line meter ........................................................... 108
109A Line/master meter .................................................... 1 09
110B Analog I/O .................................................................110
111B Power distribution ..................................................... 111
112C DCA ............................................................................ 112
113B Codec ........................................................................ 1 13
114C DSP ..............................................................................114
115E Digital I/O .................................................................. 115
119B Tape I/O ..................................................................... 119
120A Mic/control surface.................................................. 120
121A Line/control surface.................................................. 121
122A Output control surface ............................................12 2
123A Remote CPU linear power supply...........................123
124A 8-Way fader ............................................................... 124
125A 9-Way fader ............................................................... 125
136A B rain ............................................................................ 136
163C Back plane................................................................. 163
164C Clock card ................................................................. 164
201A Remote CPU power distribution.............................20 1
4
INTRODUCTION
This manual contains service information for the d8b digital audio mixer. To service the
d8b, technicians should be familiar with op-amp based and discrete analog circuitry,
digital troubleshooting, microprocessors, digital audio, DSP, ESD, ESP, and the operation/
application of mixing consoles. Presentation of this manual does not constitute
endorsement of qualifications by Mackie Designs.
This manual is available in Adobe© Portable Document Format (PDF), as part of
Mackie Designs’ Digital Service CD-ROM (part# 820-163-00). This is available to all Service
centers authorized to repair the d8b. Also included on the CD-ROM are the schematics,
PCB layouts, parts lists, assembly drawings, some IC data sheets and the owner’s
manual.
It is essential that you become familiar with the owner’s manual as it contains all of
the operational details, hookup diagrams, specifications and just about everything
d8bwegian. It will be a great help for you to verify customers complaints, and to check
for correct operation.
This service manual does not include an in-depth circuit analysis, rather it provides an
overall guide to details not immediately obvious from the schematics alone. It is
intended to help you troubleshoot down to board level and identify and swap out any
bad circuit boards. Component level troubleshooting down to resistor or IC level, may
be undertaken if time permits, or if there appears to be something obvious.
SERVICE TECHNICAL ASSISTANCE
Mackie Designs, Service Technical Assistance, is available 8AM - 5PM PST, Monday through
Friday for Authorized Mackie Service Centers, at 1-800-258-6883. Feel free to call with any
questions and speak with a carefully-calibrated technician. If one is not available, leave
a detailed message and a qualified Mackoid will return your call asap.
DISCLAIMER
The information contained in this manual is proprietary to Mackie Designs, Inc. The entire
manual is protected under copyright and may not be reproduced by any means without
express written permission from Mackie Designs Inc.
GETTING STARTED
Upon receiving a d8b for repair, your first impression may be to run screaming into the
night. After reading this overview, checking the schematics, pcb layouts, assembly
drawings, parts lists, having a good look at the owner’s manual and inspecting the unit,
you will probably realize that your first impression was correct.
Think of the remote CPU as a standard PC with extra power supplies for the console.
Standard PC troubleshooting techniques and commercially available diagnostic DOS
software can be applied to repair the remote CPU.
In its simplest form, the mixer and the remote CPU are two boxes full of circuit boards,
all joined together with lots of connectors and ribbon cables. A preliminary inspection
will often reveal a simple problem, such as a bad connection somewhere, a loose cable,
a bad switch or control, or the CPU’s CMOS settings may need to be reset.
Our technical support team are available to discuss any d8b problems and offer
solutions. If you ever suspect that a customer’s complaint is related to the version of
Mackie software they are using, you should consult with your customer and Mackie
Designs before downloading the latest software from our website: www.mackie.com
5
OVERVIEW
The ‘Digital’ functions of the d8b can be broken down into 3 main systems; Computer,
DSP, and User Interface. The computer is a Pentium system which is contained in the
Remote CPU with the Power Supply . It communicates via standard com ports (RS-232)
to the DSP and UI systems in the console.
Remote CPU
Pentium PC
HDD, Floppy, Video
DSP
A/D – D/A converters,
24 on board DSP chips,
FX cards, I/O Cards
meters
U
ser Interface
(control surface)
Switches, V-pots, LEDs,
Flying Faders, Displays
The computer runs Mackie’s real time operating system and handles functions normally
associated with a PC such as keyboard, mouse, disk drives, video, etc. The DSP system
controls all Digital Signal Processing functions in the console. The User Interface system
reads and updates the control surface.
Commands from the UI are looped through the computer. For example, if the Mute
button on channel 1 is pressed, the UI system detects it and communicates the event to
the computer. The computer then tells the DSP system to mute CH-1, and tells the UI
system to light CH-1’s mute LED. Note that the LED is not lit by the UI system directly.
Commands can also be issued by clicking on the monitor screen (GUI). Note: the DSP
communicates the meter information directly to the UI, not looped through the
computer.
6
COMPUTER SYSTEM
HARDWARE
The computer system within the Remote CPU chassis consists of the following hardware;
• Computer motherboard
• Computer microprocessor
• RAM
• HDD, FDD
• Ethernet® Card
• SVGA Video Card
• MIDI Card, SMPTE
These are all standard PC compatible parts. However, because the drivers are written
into the Mackie OS, other similar devices may not be compatible. Also, it should be
noted that ‘upgrading’ the processor, RAM, or HDD is of little value as the Mackie OS will
not take advantage of it.
EXTRA CIRCUITRY
Circuit boards inside the Remote CPU, which are not normally found inside a standard
PC are: extra power supplies, AC line and fusing circuits, chicken soup machine etc.
• Mackie board 201 is the remote CPU’s power distribution
• Mackie board 123 is a Linear power supply for the consoles analog functions
• An OEM 5V supply for the consoles digital functions
SOFTWARE
The d8b’s computer runs Mackie’s real time operating system.
THERE IS NO MS-DOS OR WINDOWS IN THE SYSTEM!
You will not find COMMAND.COM, CONFIG.SYS, or AUTOEXEC.BAT anywhere on the hard
drive. After the BIOS starts, the system boots directly into the Mackie Operating System.
CMOS setup can be accessed as in a regular PC.
The Mackie OS also contains the operating software for the DSP and UI systems. Most
future upgrades can be done without swapping EPROMS.
Please talk to our technical support team to discuss the d8b problems you are
experiencing. There is a good chance that a customer’s complaint may be cured by
upgrading to the latest sotware version. You will first need the customer’s permission
before downloading any upgrades from our website (www.mackie.com).
TROUBLESHOOTING THE COMPUTER
A common error message you might see is “System Error 43 - Host did not boot.”
The possible reason for this may be:
• The computer did not get through BIOS correctly.
• A static charge may have reset your BIOS CMOS settings.
• The data cable between the computer and the console is not connected, or is
not a straight through 25 pin din connecter.
Possible Solution:
• Connect a keyboard and monitor and press F1 to enter the computer’s BIOS
during a boot.
• Once inside the BIOS, use the AUTODETECT hard drive menu and this will likely fix
the errors you are having, once the detected drive information is saved.
(See also the notes on the following page).
7
CMOS SETUP
If you encounter “System Error 43,” Check the following CMOS setup which you can reach
during bootup by pressing Del (or F1 depending on the age of the console).
• Enter the standard CMOS setup screen, change the Primary Master to AUTO
• Next go to the Advanced CMOS setup and check the following:
(highlight and use PgUp/PgDn to modify).
Ist Boot Device ..................... Floppy
2nd Boot Device .................. IDE-0
3rd Boot Device ................... Disabled (CD-ROM)
4th Boot Device ................... Disabled
Try other Boot Devices......... Yes
S.M.A.R.T for Hard Disks........ Disabled
Quick Boot ............................ Enabled
When you have finished checking and/or making any corrections, press F10 to save the
settings and exit. Then Reboot and see if this has done the trick, and the “System Error 43”
has gone away.
NOTE: from November 1999 (serial numbers with prefix “BS11954” or higher), the
motherboard changed to 480-039-00, and there are different CMOS settings:
Press and Hold <Delete> key to go to BIOS Setup program
Using the arrow keys, select STANDARD CMOS SETUP, Press <Enter> (“Page Up” and
“Page Down” keys, and number pad can be used to change BIOS values).
Change the Date to current day, month, year. Press <Enter>
Change Time to current time (24-hour clock), Press <Enter>
Make sure all HARD DRIVES on table are set to “AUTO” MODE
Change “Halt On:” to “All, But Keyboard”, Press <Enter>
Back out to root menu by pressing <Esc>
Select “BIOS FEATURE SETUP” and make sure “Boot Sequence” is “A,C,SCSI”. <ESC>
Select CHIPSET FEATURES SETUP, Press <Enter>
Change “PCI 2.1 Compliance” to “Enabled”.
Change “Spread Spectrum” to “Enabled” and then <ESC> to main BIOS menu.
Select INTEGRATED PERIPHERALS, <Enter>
Change “Init Display First” to “PCI Slot”, <Enter>
Make sure “Onboard Serial Port 1” is set to “3F8/IRQ4” and “Onboard Serial Port 2”
is set to “2F8/IRQ3”, then press <ESC> to return to the main BIOS menu.
Select SAVE & EXIT SETUP. Type “Y” for yes, <Enter>
Bootup Num Lock................ On
Floppy Drive Swap............... Disabled
Floppy Drive Seek................. Enabled
PS/2 Mouse support ............. Auto
System Keyboard.................. Absent
Primary Display ..................... VG A/ EG A
Password Check .................. Setup
FURTHER TROUBLESHOOTING
If the CMOS setup is correct and a problem still remains, you will have to delve into the
Remote CPU and troubleshoot the computer system.
The computer can be booted with a DOS system floppy for running all of your favorite
DOS diagnostic programs. To do this:
• Find or make a bootable floppy, i.e. one which has the DOS system installed.
• Place the disc in the drive before turning on the Remote CPU.
• The computer should start up into DOS from this disc, rather than from the Mackie
OS.
• Insert any standard DOS diagnostic software and run tests, for example on the
hard drive, video card, mother board etc.
Check the extra Mackie power supply voltages are correct, as shown on the
schematic chapters 201 (power distribution) and 123 (Linear power supply). Also check
the voltages on the console end: see the console power distribution board chapter 111.
8
DSP SYSTEM
A simplified block diagram of the DSP system is shown on the next page. At the heart of
the system is an Analog Devices ADSP-2181. It acts as the console CPU, and controls all
functions and communications within the DSP system. There are 24 proprietary DSP chips
to handle the actual audio processing. Parallel processing with the 24 DSPs allows the
d8b to complete all processing within one sample.
Operating instructions are loaded from the Remote CPU as the system boots. The
EPROM does not contain operating firmware. Think of the EPROM as BIOS, it provides the
system with basic instructions to make sure it powers up correctly and sets up to receive
the operating software from the Remote CPU.
CLOCKS
All audio clocks for the DSP system originate at the clock (sync) card. The master clock is
512 x sample rate. See page 24 for some more details.
CODEC BOARD
The CODEC board contains 24 channels of A/D and D/A. Each ADC converts two
analog audio signals into a two channel serial format which is sent to the DSP chips. All
digital audio signals within the d8b are in this two channel format. The DACs convert this
stream back to 2 channels of lovely analog audio.
DSP BOARD
Each of the 24 DSP chips has two serial inputs, DR_0 and DR_1, and two serial outputs,
DT_0 and DT_1, a total of 48 inputs and 48 outputs (remember that each serial input is 2
channels of audio, so that’s 96 channels!, but they’re not all used). Digital audio data
comes from and is sent to the CODEC board, I/O cards, and FX cards.
Y2 is the processor clock from which is derived CLK_1, CLK_2, CLK_3, CLK_4 and CLKIN.
Y1 is a UART clock.
The processing algorithm works in such a way that each serial output consists of one
mix and one direct output. In order to route mixes to the same DACs the serial data is
juxtaposed in sync with the L/R clock.
There are three status indicators on the board: D2 (green),D3 (yellow), D1 (red).
DSP INPUTS DSP OUTPUTS
12 Mic/Line Inputs 8 Subgroups
12 Line Inputs 2 L/R Mix
24 Tape Input Cards 24 Tape Returns Cards
16 FX Card Returns 16 FX Card Sends
2 Meter (monitor) 12 Aux sends
8 Alt Input Card 8 Alt Output Card
2 Solo
•If all three are on, a fault has been detected.
•If the red LED is on solidly, then this is operating OK.
9
CODEC BOARD -113
ANALOG
AUDIO
INPUTS
DSP BOARD -114
STATUS LEDS
ADSP-2181
CPU-DSP
ADC
x13 x12
DSP
CHIP
SELECT
IAD0-IAD15
A0-A13
EPROM
DAC
DR0 DT0
DR1
LATCH
DSP
DT1
x24
WOOP-DEE
ANALOG
AUDIO
OUTPUTS
x6
BACKPLANE BOARD -163
PIC PICPICPIC
DSP
CLOCK
D8-D23
FX
DSP
EFFECTS CARD
AES/EBU
AES/EBU CARD -115 TAPE I/O CARD -119CLOCK CARD -164
UART
TO PC COM-2
DSP_TX
DSP_RX
TO BRAIN
ADC
DAC
APOGEE I/O CARD
AES/EBU 8-CH I/O CARD
BOARD
x4
10
UI SYSTEM
A simplified block diagram of the User Interface system is shown on the next page. Like
the DSP system, an Analog Devices ADSP-2181, is used as the CPU. It controls all functions
and communications within the UI system. Also, like the DSP system, operating
instructions are loaded from the Remote CPU as the system boots. If the UI system does
not ‘find’ the Remote CPU, it will display ‘ERROR 43 HOST COMPUTER NOT FOUND’ in the
VFD.
CLOCKS
Unlike the DSP system, the UI system runs on its own clock. The Clock (Sync) card is for the
DSP system only. Keep the clock’s main spring wound up.
BRAIN BOARD
The Brain Board reads in two types of information from the control surface. Switches are
scanned in through PISO shift registers and transferred to the Brain as serial data. Analog
voltages from faders and V-pots are multiplexed, then sent to an ADC on the Brain
board.
The Brain Board also communicates via UART to all expansion cards. Every card used
in the d8b has a PIC chip. The PIC chip outputs a copyrighted text string so that the d8b
can verify the card is original and Mackie-authorized. Cards in which operating
parameters can be varied are controlled via the Brain (UI System). The Brain Board also
controls all functions on the DCA board.
X1 is the brain processor clock, X2 and X3 are UART clocks.
The Brain board has three status indicators: D3 (green),D2 (yellow), D1 (red).
CONTROL SURFACE
Control surface LEDs, including V-pot indicators, are updated via SIPO shift registers. To
control the fader motors, serial data is sent from the Brain board to a DAC on the fader
board.
VU METERS
The VU meter LEDs are updated via shift registers but function differently than the control
surface. Remember that the control surface commands are looped through the
Remote CPU; VU meter information is not. The information for the VU meters comes
directly from the DSP Board, and is communicated to the Brain Board via UART.
• If they are all on, it did not read the
EPROM.
• If only the green is on, then it read
the EPROM but did not download
the software.
• When it is running correctly, only the
red LED should be on (and blinking).
11
CONTROL SURFACE -120 -121 -122
SWITCHES LEDS V-POTS
SHIFT
REGISTERS
SHIFT
REGISTERS
MUX
BRAIN BOARD -136
FADER BOARDS -125 -125
DAC
SHIFT
REGISTERS
FLYING
FADERS
x 25
MUX
STATUS LEDS
JOG
WHEEL
ADSP-2181
CPU-DSP
SYSTEM
CLOCK
BACKPLANE BOARD -163
A0-A13
CLK1
CLK2
LATCHS
I/O BUFFERS
EPROM
D8-D23
UARTUART
ADC
LATCHES
I/O BUFFERS
UART
TO VFD
DRIVER
VU METERS
DCA BOARD
PC COM-1
RS232
DSP
12
PIC PICPICPIC
DSP
CLOCK
FX
DSP
EFFECTS CARD
AES/EBU
AES/EBU CARD -115 TAPE I/O CARD -119CLOCK CARD -164
ADC
DAC
APOGEE I/O CARD
AES/EBU 8-CH I/O CARD
x4
ANALOG SYSTEMS
NOTE: The Bus numbers as written on the schematics for the CODEC and DCA
board are reverse numbered by the software. So Bus 1 on the schematic is
really Bus 8, Bus 2 is really Bus 7, Bus 3 = 6, Bus 4 = 5, Bus 5 = 4, Bus 6 = 3,
Bus 7 = 2 and Bus 8 = 1.
The analog circuits used in the d8b should be familiar to anyone with experience
servicing Mackie products. The 12 Mic Pre’s are the same circuit which is used in the
SR40•8. The line amps use Mackie’s ‘unity plus’ architecture.
DCA BOARD
As the name suggests, the DCA board contains Digital Controlled Amplifiers to control
the level of analog signals in the console’s monitor section. The DCA board also
contains an analog switching matrix to select and route monitor signals. The Brain Board
controls switching and level functions on the DCA Board. DCAs are controlled by a serial
data line. Analog switches are controlled by SIPO shift registers, except for TALK and
PUNCH which are controlled directly by the Brain board’s CPU.
POWER
POWER SUPPLIES
There are three power supplies within the Remote CPU chassis. A standard PC power
supply for the Pentium Motherboard, a +5V, 100W OEM switching supply for the console’s
digital functions, and an analog supply for the console’s analog functions.
The PC supply and the OEM supply should be treated as ‘black boxes’ and swapped
if bad. The analog supply is nearly identical to the design used in the SR24•4,
troubleshooting should be fairly straightforward.
POWER DISTRIBUTION
In the console, power is sent from the Power Distribution Board (111) to the Brain, DSP,
Backplane, and Analog I/O boards. These boards then distribute power to the remaining
boards.
Note: there are many bypass capacitors used throughout the console. If one of the
power supply rails is low or intermittent, one of these may have shorted, but it not an
easy thing to find which one. It will be a great help if you have a low impedance ohm
meter. You should then be able to narrow in on the offending cap or ferrite.
NOTE:
The d8b keeps the same jumper designations for all PCBs, Hurrah! So J35 on the output
board is also J35 on the Brain board. See the connectors chapter for complete details of
every connector and pinout used in the console.
If the d8b has optional I/O cards installed, use a slotted screwdriver to make sure the
installation screws are tightly secured, and not just finger-tight.
13
DSP SIGNAL FLOW
The DSP board is the central hub of the signal flow system, the digital signals must find their way to the
DSP board, get DSP’d and make their way out again to the big audio ocean.
Please take a look at the Block diagrams chapter, especially the diagram on page D3, and the DSP
map on the next page. Also see the connectors chapter for details of every connector and pinout.
Signal names (golden rule)
Throughout the console, you will see digital signal names beginning with DR and DT. Anything which
starts with DR is a digital signal on its way to the DSP board, any signal which starts with DT has come from
the DSP board. Do not be surprised to see a few of the signals change name or number as they go from
one board to the next, (but the DT or DR start part will not change).
Analog input signals
Analog audio signals coming from the Line inputs or Mic inputs are converted to digital by the CODEC
board. Each pair of analog signals is combined to form one digital serial stream (DR) sent to the DSP. There
are a total of 12 digital signals (from 12 analog pairs)
Analog audio signals from the Tape cards are converted to digital by the Tape card’s own D/A
converters, and also paired to form digital data (DR) sent to the DSP board. Each Tape card has 8 audio
inputs and this yeilds 4 digital signals per card, or a total of 12 digital signals from the three tape cards.
Digital input signals
Digital input signals coming in from the standard Digital I/O card and the PDI•8 digital I/O card are
passed to the DSP board (DR). The incoming signals are already in the 2 channel digital serial form. The
standard Digital I/O card has 1 digital input, the PDI•8 card has 4.
Digital input and output signals from the effects cards
There are slots for up to four effects cards. Each card can send and receive two digital signals to and
from the DSP board.
DR (data received by DSP)
Digital data received by the DSP board for processing is labelled starting with DR. Each of the 24 DSP
ICs can receive two digital data streams, so you will see DR0_ and DR1_, followed by which DSP IC is used,
such as U1 , U3 or U24.
DT (data transmitted by DSP)
Digital data which is transmitted by the DSP board is labeled starting with DT. Each of the 24 DSP ICs
can transmit two outputs DT0_ and DT1_.
12 digital signals go to the CODEC board to become these analog signals: 8 Buses, Mix L, Mix R, Solo L,
Solo R and 12 Auxes.
12 digital signals go to the 3 Tape Cards (which have their own A/D convertors) to become 24 analog
tape outputs.
8 digital signals go to the 4 Effects cards, 1 goes to the Digital I/O and 4 to the PDI•8 I/O card. The
signals to the I/O cards are not converted to analog, but pass out of the digital output connectors on the
rear panel of each card for digital recording. Note that each signal is still really a pair such as L/R.
14
DSP SIGNAL FLOW
DSP map
This table shows the data received (DR) and data transmitted (DT) by the DSP board. On a scale of 1
to 10, you will find this table fairly useful.
INPUT ADC SIG CABLE DSP JUXT SIG NAME(DSP) CABLE SIG NAME DAC OUTPUT
LINE 13+14 CODEC U3 DR1 J13-3 DR0_U1 DT0_U1 U46 (DT0_U2) DT_1 J13-1 DT1 CODEC U52 BUS 1+2
FX-1 J24-23 DR1_U1 DT1_U1 J24-1 DT1_U1 FX-1
LINE 15+16 CODEC U103 DR2 J13-7 DR0_U2 DT0_U2 U46 (DT0_U1) DT_2 J47-2 DT_2 TAPE I/O TAPE 17+18
FX-1 J24-25 DR1_U2 DT1_U2 J21-13 DT1_U2 FX-1
LINE 17+18 CODEC U203 DR3 J13-11 DR0_U3 DT0_U3 U46 (DT0_U4) DT_3 J13-5 D T2 CODEC U152 BUS 3+4
FX-2 J24-7 DR1_U3 DT1_U3 J24-5 DT_3 FX-2
LINE 19+20 CODEC U303 DR4 J13-15 DR0_U4 DT0_U4 U46 (DT0_U3) DT_4 J47-6 DT_4 TAPE I/O TAPE 19+20
FX-2 J24-9 DR1_U4 DT1_U4 J21-15 DT1_U4 FX-2
LINE 21+22 CODEC U403 DR5 J13-19 DR0_U5 DT0_U5 U86 (DT0_U6) DT_5 J13-9 D T3 CODEC U252 BUS 5+6
FX-3 J24-13 DR1_U5 DT1_U5 J24-11 DT_5 FX-3
LINE 23+24 CODEC U503 DR6 J13-23 DR0_U6 DT0_U6 U86 (DT0_U5) DT_6 J47-10 DT_6 TAPE I/O TAPE 21+22
FX-3 J24-15 DR1_U6 DT1_U6 J21-17 DT1_U6 FX-3
RET 1+2 CODEC U603 DR7 J13-27 DR0_U7 DT0_U7 U86 (DT0_U8) DT_7 J13-13 DT4 CODEC U352 BUS 7+8
FX-4 J24-19 DR1_U7 DT1_U7 J24-17 DT_7 FX-4
RET 3+4 CODEC U703 DR8 J13-31 DR0_U8 DT0_U8 U86 (DT0_U7) DT_8 J47-14 DT_8 TAPE I/O TAPE 23+24
FX-4 J24-21 DR1_U8 DT1_U8 J21-19 DT1_U8 FX-4
RET 5+6 CODEC U803 DR9 J12-3 DR0_U9 DT0_U9 U89 (DT0_U10) DT_9 J13-17 DT5 CODEC U452 L/R MIX
ALT I/O J48-21 DR1_U9 DT1_U9 J48-19 DT1_U9 ALT I/O
RET 7+8 CODEC U903 DR10 J12-7 DR0_U10 DT0_U10 U89 (DT0_U9) DT_10 J47-19 DT_10 TAPE I/O TAPE 9+10
ALT I/O J48-25 DR1_U10 DT1_U10 J48-23 DT1_U10 ALT I/O
RET 9+10 CODEC U1003 DR11 J12-11 DR0_U11 DT0_U11 U89 (DT0_U12) DT_11 J13-21 DT6 CODEC U552 L/R SOLO
ALT I/O J48-29 DR1_U11 DT1_U11 J48-27 DT1_U11 ALT I/O
RET 11+12 CODEC U1103 DR12 J12-15 DR0_U12 DT0_U12 U89 (DT0_U11) DT_12 J47-23 DT_12 TAPE I/O TAPE 11+12
ALT I/O J48-33 DR1_U12 DT1_U12 J48-31 DT1_U12 ALT I/O
TAPE IN 17+18 I/O CARD J47-4 DR0_U13 DT0_U13 U92 (DT0_U14) DT_13 J13-25 DT7 CODEC U652 AUX 1+2
DR1_U13 DT1_U13
TAPE IN 19+20 I/O CARD J47-8 DR0_U14 DT0_U14 U92 (DT0_U13) DT_14 J47-27 DT_14 TAPE I/O TAPE 13+14
DR1_U14 DT1_U14
TAPE IN 21+22 I/O CARD J47-12 DR0_U15 DT0_U15 U92 (DT0_U16) DT_15 J13-29 DT8 CODEC U752 AUX 3+4
DR1_U15 DT1_U15
TAPE IN 23+24 I/O CARD J47-16 DR0_U16 DT0_U16 U92 (DT0_U15) DT_16 J47-31 DT_16 TAPE I/O TAPE 15+16
DR1_U16 DT1_U16
TAPE IN 9+10 I/O CARD J47-21 DR0_U17 DT0_U17 U95 (DT0_U18) DT_17 J12-1 DT9 CODEC U852 AUX 5+6
DR1_U17 DT1_U17
TAPE IN 11+12 I/O CARD J47-25 DR0_U18 DT0_U18 U95 (DT0_U17) DT_18 J48-2 DT_18 TAPE I/O TAPE 1+2
DR1_U18 DT1_U18
TAPE IN 13+14 I/O CARD J47-29 DR0_U19 DT0_U19 U95 (DT0_U20) DT_19 J12-5 DT10 CODEC U952 AUX 7+8
DR1_U19 DT1_U19
TAPE IN 15+16 I/O CARD J47-33 DR0_U20 DT0_U20 U95 (DT0_U19) DT_20 J48-6 DT_20 TAPE I/O TAPE 3+4
DR1_U20 DT1_U20
TAPE IN 1+2 I/O CARD J48-4 DR0_U21 DT0_U21 U98 (DT0_U22) DT_21 J12-9 DT11 CODEC U1052 AUX 9+10
DR1_U21 DT1_U21
TAPE IN 3+4 I/O CARD J48-8 DR0_U22 DT0_U22 U98 (DT0_U21) DT_22 J48-10 DT_22 TAPE I/O TAPE 5+6
DR1_U22 DT1_U22
TAPE IN 5+6 I/O CARD J48-12 DR0_U23 DT0_U23 U98 (DT0_U24) DT_23 J12-13 DT12 CODEC U1152 AUX 11+12
DR1_U23 DT1_U23
TAPE IN 7+8 I/O CARD J48-16 DR0_U24 DT0_U24 U98 (DT0_U23) DT_24 J48-14 DT_24 TAPE I/O TAPE 7+8
DR1_U24 DT1_U24
This is data going into the
DSP board.
This is Data on the DSP board,
showing which DSP does what.
This is Data transmitted by the DSP
NOTE: some of the signal names
completely change name at the
connectors, especially J12 and J13.
See the CODEC map
15
DSP SIGNAL FLOW
J12
Digital data to
and from CODEC
Digital data to
and from CODEC
To and from
BACKPLANE
(Clock, Effects
and Digital I/O data)
To and from
BACKPLANE
(Effects data)
NOTE: UNMUTE is
a very important
line
To and from
BACKPLANE
(Tape I/O data)
To and from
BACKPLANE
(Tape I/O and
Alt I/O Data)
REMOTE CPU
(serial port)
J21
J48
J25
J47
J13
J24
J47
J48
J21
J24
J42
J25
J13
J12
J1
DSP 114
DSP CONNECTORS
This is a compilation of all the DSP board’s
connectors, mainly showing the data received and
transmitted, and clocks. The power and ground pins
are not shown here, to make things a little clearer.
These can be found in the connectors chapter, or on
the schematics.
16
DSP SIGNAL FLOW
CODEC BOARD
IC Connector/pin
Analog
OUT
U52
U152
U252
U352
U452
U552
U652
U752
U852
U952
U1052
U1152
MIX-L MIX-R DT5
SOLO-L SOLO-R DT6
AUX-1 AUX-2 DT7
AUX-3 AUX-4 DT8
AUX-5 AUX-6 DT9
AUX-7 AUX-8 DT10
AUX-9 AUX-10 DT11
AUX-11 AUX-12 DT12
Analog
OUT
BUS-2 DT1BUS-1
BUS-4 DT2BUS-3
BUS-6 DT3BUS-5
BUS-8 DT4BUS-7
DT
from DSP
How it is labeled
out of DSP board
DT_1
DT_3
DT_5
DT_7
DT_9
DT_11
DT_13
DT_15
DT_17
DT_19
DT_21
DT_23
J13-1
J13-5
J13-9
J13-13
J13-17
J13-21
J13-25
J13-29
J12-1
J12-5
J12-9
J12-13
The Data transmitted
(DT) from the DSP board
is converted to Analog
and split out into its two
component signals. For
example, DT_1 comes
off the DSP board to the
CODEC (using J13 pin 1),
where it is renamed DT1.
U52 converts DT1 into
analog signals BUS-1
and BUS-2.
The analog signals, such
as Bus, Aux, Mix and Solo
then go off to the DCA
board via J11
IC DR to DSP
Analog
IN
U3
U103
U203
U303
U403
U503
U603
U703
U803
U903
U1003
U1103
U4
METER-L METER-R METER_DR
Analog
IN
LINE-14 DR1LINE-13
LINE-16LINE-15
LINE-18LINE-17
LINE-20LINE-19
LINE-22 DR5LINE-21
LINE-24LINE-23
RET-2RET-1
RET-4RET-3
RET-6 DR9RET-5
RET-8RET-7
RET-10RET-9
RET-12RET-11
DR2
DR3
DR4
DR6
DR7
DR8
DR10
DR11
DR12
How it is labeled
into DSP board
DRO_U1
DRO_U2
DRO_U3
DRO_U4
DRO_U5
DRO_U6
DRO_U7
DRO_U8
DRO_U9
DRO_U10
DRO_U11
DRO_U12
METER_DR
Connector
/pin
J13-3
J13-7
J13-11
J13-15
J13-19
J13-23
J13-27
J13-31
J12-3
J12-7
J12-11
J12-15
J13-33
Analog signals are
converted to digital
and combined in pairs.
This gives the Data
Received (DR) which
goes off to the DSP
board.
For example, analog
signals Line 13 and Line
14 are converted by U3
on the CODEC board to
become digital signal
DR1. This passes to the
DSP board via J13 pin 3,
where it is renamed
DRO_U1.
17
DSP SIGNAL FLOW
CODEC connectors
This is a compilation of all the CODEC
board’s connectors, mainly showing
the analog inputs, data received and
transmitted. The power,ground and
clocks are not shown, but they can be
found in the connectors chapter, or on
the schematics.
J1
Analog signals
coming in from
Analog I/O
J3
Analog signals
coming in from
control surface
J11 J3
J15
J2
Analog signals
going out
to Analog I/O
CODEC 113
J13
J12
J2 J1
J13
Digital signals
DT=from DSP
DR=to DSP
J12
18
DSP SIGNAL FLOW
J11
Analog signals
going out
to DCA
DCA connectors
J11
Analog signals
coming in from
CODEC board
J10
Analog signals
going out to
Analog I/O
This is a compilation of all the DCA
board’s connectors, mainly showing
the analog inputs, data received and
transmitted.
The DCA board receives the analog
Buses, Auxes, Mixes and Solos from the
DSP board, then outputs (under
control by the Brain board) to the
Analog I/O board and Bus out.
J8
Analog signals,
going to rear panel
8 BUS OUT
J9
Analog signals
going out to
Analog I/O
J8
J10J11 J9
J60
DCA 112
J31
J31
To Brain
19
DSP SIGNAL FLOW
TAPE CARDS
This shows the analog inputs and outputs on the Tape cards. The analog signals go in and out of the
rear panel DB25 connectors J101 and J102 respectively.
The Tape cards have their own D/A and A/D converters, therefore, only digital signals are passed to
and from the DSP board.
Pairs of analog inputs are converted to digital form, for example, input 8 and 7 are combined to form
digital signal DR4 which goes off to the DSP board. DT4 comes back from the DSP board, and is converted
to analog outputs 7 and 8.
NOTE: the digital signals shown below are named as they appear on the Tape card only. The names
are changed at the backplane board before going to the DSP baord. See the next page for details.
This shows the
digital signals
from the DSP
board, and the
analog output
signals they
become after
D/A conversion.
For example,
digital signal DT4
on the Tape card
comes from the
DSP board. This is
converted, and
becomes analog
signal 8 and
analog signal 7.
These appear on
the DB25 output
connector J102
for recording.
ANALOG
OUTPUT
8 GND
6 GND
5_OUT_COLD DT3
4_OUT_COLD DT2
4 GND
3_OUT_COLD DT2
2_OUT_HOT DT1
2 GND
1_OUT_COLD DT1
7 GND
6_OUT_COLD DT3
5_OUT_HOT DT3
DIGITAL
NAME
DB25
Connector/pin
DT48_OUT_HOT
DT47_OUT_COLD
DT36_OUT_HOT
J102-1
J102-2
J102-3
J102-4
J102-5
J102-6
J102-7
J102-8
J102-9
ANALOG
INPUT
8 GND
6 GND
5_IN_COLD DR3
4_IN_COLD DR2
4 GND
3_IN_COLD DR2
DIGIT AL
NAME
DR48_IN_HOT
DR47_IN_COLD
DR36_IN_HOT
DB25
Connector/pin
J101-1
J101-2
J101-3
J101-4
J101-5
J101-6
J101-7
J101-8
J101-9
This shows the
analog signals
coming in from a
tape deck, and
the digital signals
they become
after A/D
conversion.
For example,
analog signals 8
and 7 come in on
the tape card’s
DB25 input
connector J101
J102-10
J102-11
2_IN_HOT DR1
2 GND
J101-10
J101-11
and are
converted to
become digital
J102-12
J102-13
DT48_OUT_COLD
DT47_OUT_HOT
J102-14
J102-15
J102-16
J102-17
J102-18
1_IN_COLD DR1
DR48_IN_COLD
DR47_IN_HOT
7 GND
6_IN_COLD DR3
5_IN_HOT DR3
J101-12
J101-13
J101-14
J101-15
J101-16
J101-17
J101-18
signal DR4. This
then goes to the
DSP board for
processing.
5 GND
4_OUT_COLD DT2
3_OUT_HOT DT2
3 GND
2_OUT_COLD DT1
1_OUT_HOT DT1
1 GND J102-25
20
DSP SIGNAL FLOW
J102-19
J102-20
J102-21
J102-22
J102-23
J102-24
5 GND
4_IN_COLD DR2
3_IN_HOT DR2
3 GND
2_IN_COLD DR1
1_IN_HOT DR1
1 GND J101-25
J101-19
J101-20
J101-21
J101-22
J101-23
J101-24
TAPE CARDS continued
ANALOG
TAPE OUTPUT
PAIRS
23 AND 24
21 AND 22
19 AND 20
17 AND 18
15 AND 16
13 AND 14
11 AND 12
9 AND 10
7 AND 8
5 AND 6
3 AND 4
1 AND 2
DIGITAL SIG
NAME ON
TAPE BOARD
DT4
DT3
DT2
DT1
DT4
DT3
DT2
DT1
DT4
DT3
DT2
DT1
CARD TO
BACKPLANE
CONNECTOR
AND PIN NO.
J20-7,56
J20-5,58
J20-3,60
J20-1,62
J19-7,56
J19-5,58
J19-3,60
J19-1,62
J18-7,56
J18-5,58
J18-3,60
J18-1,62
WHA T THE SIGNAL
IS CALLED ON
THE BACKPLANE
AND DSP BOARD
DT_8
DT_6
DT_4
DT_2
DT_16
DT_14
DT_12
DT_10
DT_24
DT_22
DT_20
DT_18
BACKPLANE
TO DSP
CONNECTOR
AND PIN NO.
J47-14
J47-10
J47-6
J47-2
J47-31
J47-27
J47-23
J47-19
J48-14
J48-10
J48-6
J48-2
NOTE: All three tape cards
are identical, and the
difference in signal name
comes from where each
card is fitted in the
backplane slots. If a card is
fitted into slot 1-8, it
connects to the
backplane’s J18 and so for
example, the card’s DT2
becomes DT_20 on the
backplane and DSP board.
If the card is in the 9-17
slot, it uses J19 and so the
card’s DT2 becomes
DT_12.
ANALOG
TAPE INPUT
PAIRS
23 AND 24
21 AND 22
19 AND 20
17 AND 18
15 AND 16
13 AND 14
11 AND 12
9 AND 10
7 AND 8
5 AND 6
3 AND 4
1 AND 2
DIGITAL SIG
NAME ON
TAPE BOARD
DR4 DR0_U16
DR3 DR0_U15
DR2 DR0_U14
DR1 DR0_U13
DR4
DR3
DR2
DR1
DR4
DR3
DR2
DR1
CARD TO
BACKPLANE
CONNECTOR
AND PIN NO.
J20-8,55
J20-6,57
J20-4,59
J20-2,61
J19-8,55
J19-6,57
J19-4,59
J19-2,61
J18-8,55
J18-6,57
J18-4,59
J18-2,61
WHA T THE SIGNAL
IS CALLED ON
THE BACKPLANE
AND DSP BOARD
DR0_U20
DR0_U19
DR0_U18
DR0_U17
DR0_U24
DR0_U23
DR0_U22
DR0_U21
BACKPLANE
TO DSP
CONNECTOR
AND PIN NO.
J47-16
J47-12
J47-8
J47-4
J47-33
J47-29
J47-25
J47-21
J48-16
J48-12
J48-8
J48-4
These are the signals
transmitted to the DSP
board from the Tape
inputs.
What happens is this:
Two analog signals are
converted into digital and
combined into one digital
signal.
For example, analog
signals 23 and 24 (from the
DB25 pin connector on the
rear panel) are converted
and combined to create a
digital signal DR4 on the
tape card. This is then
given a new name of
DRO_U16 and sent to the
DSP board using connector J47, pin 16.
21
DSP SIGNAL FLOW
EFFECTS CARDS
There are four slots available on the backplane board for Effects cards. They can plug into the
backplane connectors J51, J16, J14 and J17. The backplane connectors J21 and J24 transmit and receive
data to and from the DSP board.In most cases, the digital signals have the same name on the backplane
as appear on the DSP board, but there are a few exceptions, shown in the right hand column of the tables
below.
EFFECTS
CARD
FX1
FX1
FX2
FX2
FX3
FX3
FX4
FX4
EFFECTS
CARD
FX1
FX1
FX2
CARD TO
BACKPLANE
CONNECTOR
AND PIN #
J51-5,58
J51-10,53
J16-5,58
J16-10,53
J14-5,58
J14-10,53
J17-5,58
J17-10,53
CARD TO
BACKPLANE
CONNECTOR
AND PIN #
J51-11,52
J51-12,51
J16-11,52
WHA T THE SIGNAL
IS CALLED ON
THE BACKPLANE
DT1_U2
DT1_U1
DT1_U4
DT_3
DT1_U6
DT_5
DT1_U8
DT_7
WHA T THE SIGNAL
IS CALLED ON
THE BACKPLANE
DR1_U1
DR1_U2
DR1_U3
BACKPLANE
TO DSP BOARD
CONNECTOR
AND PIN NO.
J21-13
J24-1
J21-15
J24-5
J21-17
J24-11
J21-19
J24-17
BACKPLANE
TO DSP BOARD
CONNECTOR
AND PIN NO.
J24-23
J24-25
J24-7
WHA T THE SIGNAL
IS CALLED ON
THE DSP BOARD
SAME
SAME
SAME
DT1_3
SAME
DT1_5
SAME
DT1_7
WHA T THE SIGNAL
IS CALLED ON
THE DSP BOARD
SAME
SAME
SAME
These are the signals
transmitted from the DSP
board to the effects cards.
These are the signals
transmitted from the
effects cards to the DSP
board.
FX2
FX3
FX3
FX4
FX4
J16-12,51
J14-11,52
J14-12,51
J17-11,52
J17-12,51
22
DSP SIGNAL FLOW
DR1_U4
DR1_U5
DR1_U6
DR1_U7
DR1_U8
J24-9
J24-13
J24-15
J24-19
J24-21
SAME
SAME
SAME
SAME
SAME
EXTRA CARD
One slot on the backplane is available for an extra digital I/O card, such as the PDI•8. It connects to
backplane connector J22 (in the ALT I/O slot). The signals to and from the DSP board pass through
backplane connector J48. There are 4 digital inputs and outputs, each carrying two data signals.
CARD TO
BACKPLANE
CONNECTOR
AND PIN #
J22-1,62
J22-3,60
J22-5,58
J22-7,56
CARD TO
BACKPLANE
CONNECTOR
AND PIN #
J22-2,61
J22-4,59
J22-6,57
J22-8,55
WHA T THE SIGNAL
IS CALLED ON
THE BACKPLANE
AND DSP BOARD
DT1_U9
DT1_U10
DT1_U11
DT1_U12
WHA T THE SIGNAL
IS CALLED ON
THE BACKPLANE
AND DSP BOARD
DR1_U9
DR1_U10
DR1_U11
DR1_U12
BACKPLANE
TO DSP BOARD
CONNECTOR
AND PIN NO.
J48-19
J48-23
J48-27
J48-31
BACKPLANE
TO DSP BOARD
CONNECTOR
AND PIN NO.
J48-21
J48-25
J48-29
J48-33
These are the signals
transmitted from the DSP
board to the extra card.
These are the signals
transmitted from the extra
card to the DSP board
DIGITAL I/O CARD
One slot on the backplane is available for the standard digital I/O card. It connects to backplane
connector J30. The signals to and from the DSP board pass through backplane connector J21. Note that
once the digital signals reach the DSP board, they change name.
CARD TO
BACKPLANE
CONNECTOR
AND PIN #
J30-1,62
J30-2,61
WHA T THE SIGNAL
IS CALLED ON
THE BACKPLANE
DR J21-11
DT
BACKPLANE
TO DSP BOARD
CONNECTOR
AND PIN NO.
J21-9
WHA T THE SIGNAL
IS CALLED ON
THE DSP BOARD
DT1_U13
DR1_U13
DSP SIGNAL FLOW
23
The clock card
The clock card generates the main clock signals used throughout the console. On other boards there
are a few local clocks used, for example, for the serial Rx and TX connection to the remote CPU.
This table shows the signal flow from the clock card to the various boards in the D8B. The clock card
fits into connector J23 on the backplane board. From there, the signals are distributed to other boards
either by ribbon connectors, or using the backplane’s buses to the Tape cards, FX cards, and Digital IO.
Have a look at the schematics/pcb layouts of the clock card. The last page of that chapter has a pcb
layout with traces and some signals and voltages marked. Also refer to the connectors chapter for more
details of each connector mentioned in the table below.
SIGNAL BACKPLANE BACKPLANE DESTINATION
NAME CONNECTION OUTPUT
D_LRCLK J23, PINS 1+62 J21, PIN 1 TO DSP BOARD
D_SCLK J23, PINS 2+61 J21, PIN 3 TO DSP BOARD
D_FSYNC J23, PINS 3+60 J21, PIN 5 TO DSP BOARD
SYNC_RX J23, PINS 5+58 J32, PIN 5 TO BRAIN BOARD
SYNC_TX J23, PINS 6+57 J32, PIN 7 TO BRAIN BOARD
B_SCLK J23, PINS 7+56 J17, PIN 8+55 TO ALL FX CARDS (J17, J14, J16 AND J51, ALL
PIN 8+55)
B_LRCLK J23, PINS 8+55 J17, PIN 13+50 TO ALL FX CARDS (J17, J14, J16 AND J51, ALL
PIN 13+50)
MCLK J23, PINS 9+54 J22, PIN 9+54 TO ALL TAPE CARDS AND EXTRA (J22, J20,
J19, J18, ALL PIN 9+54)
SCLK J23, PINS 10+53 J22, PIN 10+53 TO ALL TAPE CARDS AND EXTRA (J22, J20,
J19, J18, ALL PIN 10+53)
LRCLK J23, PINS 11+52 J22, PIN 11+52 TO ALL TAPE CARDS AND EXTRA (J22, J20,
J19, J18, ALL PIN 11+52)
MUTE J23, PINS 12+51 J15, PIN 1 TO CODEC BOARD AND ALL TAPE CARDS,
EXTRA AND DIG IO (J22, J20, J19, J18 AND
J30, ALL PINS 12+51)
RESET J23, PINS 13+50 J15, PIN 3 TO CODEC BOARD AND ALL TAPE CARDS,
EXTRA AND DIG IO (J22, J20, J19, J18 AND
J30 ALL PINS13+50) AND ALL FX CARDS (J17,
J14, J16 AND J51, ALL PIN 6+57)
UNMUTE J23, PINS 14+49 J24, PIN 27 TO DSP BOARD
A_MCLK J23, PINS 16+47 J15, PIN 9 TO CODEC BOARD
A_SCLK J23, PINS 17+46 J15, PIN 7 TO CODEC BOARD
A_LRCLK J23, PINS 18+45 J15, PIN 5 TO CODEC BOARD
24
CLOCKS
The clocks
The diagram below shows the relationship between the various clock signals generated by the clock
card.
L/R CLK
Mackie Serial Digital Audio Format
24 Bit MSB Left Justified
DATA
SCLK
MCLK
MSB
Data valid on the falling edge of SCLK
LSB
J23
J23
BACKPLANE
This is where the clock card plugs into the backplane
J23 pinouts show the signals to and from the clock card
25
CLOCKS
MUTE and UNMUTE
On the clock card, there is an important Mute/Unmute circuit. It could have been fitted to any board,
but it just so happens it was placed on the clock card. Here is the circuit:
The UNMUTE and RESET signals come from the DSP
board.
The MUTE signal will mute the D/A converters
(CS4390 pins 15 and 16) on the CODEC board and
the Tape Cards.
The left column of the table below shows the signals on the CLOCK card. This plugs into the
BACKPLANE card connector J23. The traces on the BACKPLANE lead to it’s various inputs and output
connectors such as ribbon connector J15 to CODEC, J24 and J21 to DSP, card connectors J22, J20, J19
etc.)
SIGNAL BACKPLANE BACKPLANE DESCRIPTION
NAME CONNECTION IN/OUTS
MUTE J23, PINS 12+51 J15, PIN 1 To CODEC board (J15, Pin 1)
To TAPE CARDS (J22, J20, J19, all pins 12+51)
RESET J23, PINS 13+50 J24, PIN 29 From DSP board (J24, pin 29, and J21, pin 7)
To CODEC board (J15, pin 3)
To TAPE CARDS, EXTRA and DIG IO
(J22, J20, J19, J18 and J30 all pins13+50)
To FX CARDS (J17, J14, J16 and J51,
all on pins 6+57)
UNMUTE J23, PINS 14+49 J24, PIN 27 From DSP board
NOTE that RESET is known as M_RESET on the DSP board. It simply changes name at the connectors J24 and J21.
MUTE
26
POWER
ON
POWER
OFF
SYSTEM
< System Boots DSP >
RESET
UNMUTE
MUTE
As the console powers up, the D/A converters are muted on the CODEC board and the TAPE cards.
This prevents noise form being heard or recorded on the Analog lines.
When the system has finished booting correctly, the all-important UNMUTE signal is sent from the DSP
board to this little circuit, and so the D/A converters are unmuted and ready. So, if the DSP is not booted
working correctly, the UNMUTE may not be sent, and the audio will remain muted.
If RAP music is attempted, and the words “hip ‘n a hop” or “bip ‘n a bop” detected, then the D/A
converters are muted automatically. Its only fair.
TIME
27
MUTE
QUICK PARTS
TRIM
N
E
I
L
C
I
M
060
-
20dB +40dB
1
MIC
REC/RDY
ASSIGN
WRITE
1
25
SELECT
SOLO
MUTE
Channels 1 to 12 (120 board)
ITEM REFERENCE PART # NEW PART #
130-050-02
760-081-00
500-018-00
500-037-00
760-078-00
500-033-02
304-054-02
760-104-01 760-117-01
500-033-02
304-055-02
760-104-04 760-117-06
500-033-02
304-056-02
760-104-05 760-117-05
130-045-00
304-026-00
760-063-00
760-064-00
304-037-00
304-036-00
500-033-02
304-055-02
760-105-04 760-118-04
500-033-02
304-056-02
760-105-02 760-118-02
500-033-02
304-054-02
760-105-03 760-118-03
Knob
Button
Button
Button
Button
Knob
Lens
Button
Button
Button
R105-R1205Pot
SW107-SW1207Switch
SW1301-SW2401Switch
D1301-D2401LED
SW1302-SW2402Switch
D1302-D2402LED
SW1303-SW2403Switch
D1304-D2404LED
R1301-R2401Pot
D1303-D2403LED
D1309-D2409LED
D1308-D2408LED
SW1304-SW2404Switch
D1305-D2405LED
SW1305-SW2405Switch
D1306-D2406LED
SW1307-SW2407Switch
D1307-D2407LED
Ch. 12 to 24 (121 board)
R116-R1216Pot
No MIC buttons
on 121 board
Same as 120 board
Same as 120 board
Same as 120 board
Same as 120 board
Same as 120 board
Same as 120 board
Same as 120 board
Same as 120 board
Same as 120 board
130-049-02
NOTE:
Regarding console buttons.
Early models had flat buttons:
760-104-xx and 760-105-xx.
Most consoles have an
angled button:
760-117-xx and 760-118-xx
These styles of button are not
interchangable.
If it has a flat top to each
button, they are the older
style, if they have an angle or
slope to the top, they are the
current button style.
dB
10
5
U
Faders are on the 124 and 125 boards
ITEM REFERENCE PART #
5
10
20
30
40
50
60
Fader
Knob
R1-R701
130-047-00
760-085-01
These parts are on the Mic/Line
control surface (120 board)
and the Line control surface
(121 board)
A-1
QUICK PARTS
ITEM REF PART #
SW2601Switch
D2609LED
Button
SW2602Switch
D2602LED
Button
SW2603Switch
D2603LED
Button
SW2604Switch
D2606LED
Button
SW2605Switch
D2605LED
Button
500-033-02
304-054-02
760-104-00
500-033-02
304-055-02
760-104-00
500-033-02
304-055-02
760-104-04
500-033-02
304-055-02
760-104-00
500-033-02
304-055-02
760-104-00
1-24 1-48
LEVEL TO T APE
AUX 1
AUX 3
AUX 5
AUX 7
DIGIT AL TRIM
AUX 2
AUX 4
AUX 6
AUX 8
ITEM REF PART #
M1MIC
SW2608Switch
D2609LED
Button
SW2609Switch
D2610LED
Button
SW2610Switch
D2611LED
Button
SW2611Switch
D2614LED
Button
SW2612Switch
D2613LED
Button
480-001-00
500-033-02
304-054-02
760-104-00
500-033-02
304-055-02
760-104-00
500-033-02
304-055-02
760-104-00
500-033-02
304-055-02
760-104-00
500-033-02
304-055-02
760-104-00
These parts are on the
Line control surface
(121 board)
Button
Button
Button
Button
Button
SW2606Switch
D2604LED
SW2607Switch
D2608LED
500-033-02
304-056-02
760-104-00
500-033-02
304-055-02
760-104-00
AUX 9-10
PAN
AUX 11
PAN
SW2613Switch
D2612LED
Button
-
12
SW2614Switch
D2615LED
Button
R2637Pot
D2607LED
Knob
Lens
SW2615Switch
D2616LED
500-033-02
304-055-02
760-104-00
SW2616Switch
D2617LED
SW2619Switch
D2620LED
500-033-02
304-055-02
760-105-00
500-033-02
304-055-02
760-105-00
MASTERS
MIC/LINE
MASTER
PAN
1-24
(TRACK) (MONITOR)
49-72
SOLO
SHIFT
25-48
TAPE IN
SW2617Switch
D2618LED
Button
SW2618Switch
D2619LED
Button
SW2620Switch
D2621LED
Button
SW2621Switch
D2622LED
EFFECTS
BANK SELECT
500-033-02
304-056-02
760-104-00
500-033-02
304-055-02
760-104-00
130-045-00
304-026-00
760-063-00
760-064-00
500-033-02
304-055-02
760-104-00
500-033-02
304-055-02
760-105-00
500-033-02
304-054-02
760-105-00
500-033-02
304-056-02
760-105-00
A-2
QUICK PARTS
NOTE: All small buttons are 760-104-00, later models are 760-117-00
All large buttons are 760-105-00, later models are 760-118-00
All switches are 500-033-02
ITEM REF PART #
SW16Switch
D20LED
Button
SW17Switch
D21LED
Button
SW18Switch
D22LED
Button
SW19Switch
D25LED
Button
500-033-02
304-054-02
760-104-00
500-033-02
304-054-02
760-104-00
500-033-02
304-054-02
760-104-00
500-033-02
304-054-02
760-104-00
MIXDOWN SOLO
PFL SOLO
AFL SOLO
T ALKBACK T O
STUDIO
CONTROL ROOM
STUDIO/SOLO
RUDE SOLO
LIGHT
LEVEL
ITEM REF PART #
D37LED
R5Pot
D26LED
Knob
Lens
304-006-00
130-045-00
304-026-00
760-063-00
760-064-00
SW34Switch
D32LED
Button
SW35Switch
D42LED
Button
SW36Switch
D43LED
Button
SW42Switch
D51LED
Button
500-033-02
304-055-02
760-104-00
500-033-02
304-055-02
760-104-00
500-033-02
304-056-02
760-104-00
500-033-02
304-055-02
760-104-00
All small buttons are 760-104-00,
later models are 760-117-00
All large buttons are 760-105-00,
later models are 760-118-00
All switches are 500-033-02
SW37Switch
D44LED
Button
500-033-02
304-055-02
760-105-00
2 TRACK A
2 TRACK B DIGITAL IN 2
2 TRACK C
NEAR FIELD
SPEAKERS
SPEAKER LEVEL
SPEAKER LEVEL
DIM
MONO
DIGITAL IN 1
MASTER
L-R
MAIN
TALKBACK
CLIP BOARD
Button
Button
Button
Button
Button
Knob
Lens
Button
SW38Switch
D47LED
500-033-02
304-055-02
760-104-00
SW39Switch
D48LED
500-033-02
304-055-02
760-104-00
SW40Switch
D49LED
500-033-02
304-056-02
760-104-00
SW81Switch
D17LED
500-033-02
304-056-02
760-104-00
SW43Switch
D52LED
500-033-02
304-055-02
760-104-00
R8Pot
D45LED
130-045-00
304-026-00
760-063-00
760-064-00
SW57Switch
D66LED
500-033-02
304-055-02
760-105-00
Button
Button
Button
Button
SW41Switch
D50LED
SW54Switch
D63LED
500-033-02
304-054-02
760-104-00
500-033-02
304-054-02
760-104-00
CUT/ZERO SET
PASTE
COPY
UNDO
SW62Switch
D71LED
Button
SW65Switch
D74LED
Button
500-033-02
304-054-02
760-104-00
500-033-02
304-054-02
760-104-00
These parts are on the
Output control surface
(122 board)
MASTER L/R SHORTCUTS
SW76Switch
D85LED
SW74Switch
D83LED
500-033-02
304-054-02
760-104-00
500-033-02
304-054-02
760-104-00
SELECT
WRITE
CONTROL
ALT
Button
Button
SW77Switch
D86LED
500-033-02
304-054-02
760-104-00
SW75Switch
D84LED
500-033-02
304-054-02
760-104-00
A-3
QUICK PARTS
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