AB64 Service Manual

Return to HFI Home Page

USER'S MANUAL

AudioBox AB64

updated 2 October 2006

Contents

• Introduction
• Environment
• Power Supply
• Internal Disk Drive
• Network Connection
• MIDI Connections
• Boot to ROM
• Boot from Slave Drive
• LCD screens
• Audio Connections
• GPIO
• Adding DSP and Analog Cards
• Adding CobraNet Modules
• Recording and Playing Back Audio
• Repacking an AB64 for shipping
• Return to HFI Home Page

---

Introduction

The AudioBox AB64 Disk Matrix Mixer is a sophisticated multi-channel dynamic audio controller. It can be configured for 16, 32, 48 or 64 channels of audio input and output. The disk drive unit provides up to 64 independent channels of digital audio to the matrix mixer. An internal show controller can be used to automate internal AudioBox functions, as well as control external equipment via MIDI Show Control.

The AudioBox complies with the AES5-1998 48kHz Single Sampling Frequency standard.

Environment

The unit is designed for mounting in a standard 19" rack, requiring a two "U" rack space. All connections are made at the back panel of the unit. The AB64 will operate reliably under conditions normal for audio equipment: temperature no more than about 20 degrees centigrade above or below room temperature, not exposed to rain or excessive moisture, shock or G-forces above what standard disk drives will tolerate, etc. The front panel contains an LCD display and five pushbutton switches, two for power and three that perform various functions as indicated on the LCD display. Never attempt to clean the front panel using strong solvents, such as methyl hydrate, etc. Use a mild cleaning solution or rubbing alcohol to clean the panel and LCD.

The opening for the LCD in the front panel is also an air intake. Covering or blocking this opening (for example with clear tape) will cause over-heating and will void the warranty. Similarly, the opening in the right side panel near the front is an air outlet. Covering or blocking this opening will also void the warranty.

Power Supply

A 13.8 volt DC output, 130W external power supply (model SPU-130) is supplied with the AudioBox. It accepts a universal range of AC power: 115-230 VAC and 50-60 Hz. The power supply plugs into a circular, two conductor power socket (2.1 mm barrel type) on the back panel of the AudioBox (marked "POWER"). There are no restrictions regarding the order in which the AC and DC cables are connected.

If the power jack becomes loose in the power socket, remove the jack and use a small slot screwdriver to increase slightly the separation between the two halves of the center pin inside the power jack. It is also possible to pull the spring at the back of the jack slightly towards the middle of the jack.

The input voltage to the AudioBox must be kept at all times within the range13.0 to 15.0 volts DC. If the input voltage goes below 13 volts, an LED next to the power jack marked "LO" will light, and a message will also appear on the main LCD screen. (The unit itself may be able to operate with an input voltage well below 13 volts, but the disk drive will not.) If the input voltage goes above 15 volts, an LED next to the power jack marked "HI" will light. If the unit is running it will shut down immediately to protect the internal electronics. If the unit is off, it will not power on until the voltage is brought below 15 volts.

The AudioBox draws 1.5 up to approximately 6.5 amps at 13.8 volts, depending on configuration. Contact Richmond Sound Design before using the AudioBox with any power source other than the external power supply that is shipped with the AudioBox. Connection to an improper power supply could damage the AudioBox and/or the internal disk drive and void the AudioBox and/or disk drive warranty.

Remote Startup

Early production units do not power on immediately when external power is applied; the front panel "ON" button must be pressed to start the unit. A capacitor can be added to the main CPU circuit board that will allow the unit to power on when external power is applied (remote startup). The front panel "ON" and "OFF" buttons operate normally in this configuration, with the small difference that the "OFF" button must be held down for a short time before the unit powers down. Later production units are shipped with this capacitor installed. This capacitor can be removed if remote startup is not desired. The capacitor must be rated for 25 volts or more and must have a value of 22 to 100 microfarads. The capacitor is installed into two 0.038" holes in the circuit board labeled "TP21" and "TP19". These are located near the back of the MIDI 2 "IN" connector.

Bypassing the Front Panel Power Buttons

A jumper can be added to the main CPU circuit board to bypass the "ON" and "OFF" pushbuttons on the front panel. With this jumper in place, the front panel "ON" and "OFF" pushbuttons have no effect and the unit powers up immediately when DC power is applied. The unit is turned off by removing DC power. The jumper, a short length of solid wire, must be soldered in place for reliability. Any gauge of wire is acceptable; the jumper will carry negligible current. The jumper connects two 0.038" holes in the circuit board labeled "TP21" and "TP19". These are located near the back of the MIDI 2 "IN" connector.

Internal Disk Drive

The AB64 stores audio, show files, firmware and user parameters on an internal disk drive. At least one disk drive must be installed before the AB64 can be used.

Disk Requirements

• 3.5" disk form factor
• ATA 40-pin parallel interface
• Ultra 100 or faster
• Average seek time 10 ms or less
• Maximum 5V current: 1000mA
• Maximum 12V current: 2500mA (maximum current is usually start-up current)

The AudioBox plays audio tracks at 48,000 16-bit samples per second. Therefore, the disk storage space required for audio files is 96000 bytes per second per monaural track, or 5.76 megabytes per minute. An 80 GB disk drive will store approximately 13,900 minutes (232 hours) of single-track audio.

For information on choice of disk drive for the AudioBox, see AudioBox Hard Drives on the Richmond Sound Design web site. (The disk drive is warranted by its manufacturer, not Harmonic Functions.)

Drive Replacement / Installation

1. Remove AudioBox power cable.
2. Remove the top cover.
3. Disconnect the power and data cables from the disk drive on the upper mounting plate. The power connector is most easily removed using a pair of ordinary pliers. The data cable can be loosed and removed by gently pulling on the connector and /or the data cable.
4. Remove the four mounting screws holding down the mounting plate. Lift the plate out of the chassis.
5. For access to the disk drive on the lower level, remove the four 1.25" #6 hex standoffs holding the lower disk drive plate.
6. Remove the four screws from the bottom of the plate to remove the drive from the plate.
7. The configuration jumper(s) on disk drives being installed should be set for "cable select". See the instructions that came with the disk drive.
8. Mount the disk drive(s) to the mounting plate(s) using four #6 x 1/4" machine screws. Mounting plates supplied without a factory-installed disk drive come with the four machine screws needed to mount a disk drive attached with hex nuts. Unscrew these machine screws from the hex nuts holding them in place and discard the nuts. The rear edge of the drive should be about 0.5" in from the rear of the mounting plate, leaving 1.5" of room for the cabling at the front of the drive (mounting plates in early production units are drilled so that the drive is centered on the plate). If only one drive will be in the unit, it should be installed in the upper plate location.
9. Mount the lower disk drive plate with disk drive (if any) to the chassis using the four 1.25" #6 hex standoffs removed in step 5. If there is a disk drive on the lower plate, connect the data and power cables before installing the hex standoffs on the front edge of the plate. Do not overtighten the standoffs; the threaded post will break off if severely over-tightened. The data connector in the middle of the data cable (gray) must be used with the disk drive on the lower plate. This drive is referred to as "slave" or "secondary". Either power connector may be used.
10. Mount the upper disk drive plate with attached disk drive to the hex standoffs using four #6 x 3/8" machine screws. Connect the data and power cables before installing the machine screws and lockwashers on the front edge of the plate. The data connector on the end of the data cable (black) must be used with the disk drive on the upper plate. This drive is referred to as "master" or "primary". Either power connector may be used.
11. Reconnect power and test. Replace top cover.

Drive Initialization

When a new drive is installed, AudioBox firmware must be installed using the firmware installer program appropriate for the host computer. See the Richmond Sound Design web site to download the Windows installer and the download page on this web site for the Mac OS X installer (ABshowMaker or ABTools). During the firmware installation, the disk is initialized automatically; no additional actions are required to make the drive ready to use. Low-level reformatting is not required when a new drive is installed.

Drive Defragmentation

AudioBox control programs indicate how much disk space could be recovered by performaing a defragmentation of the internal AudioBox disk (as well as the means to initiate a defragmentation). A defragmentation recovers unuseable disk space that accumulates as files are erased and re-written on the disk. Defragmentation can take a long time, depending on how much audio is on the disk. The only legitimate reason to defragment a disk is to retrieve disk space when a disk is almost full and the recoverable disk space is needed. Defragmenting a disk will not repair a damaged disk directory or correct any other fault condition. Nor will defragmenting a disk make playback work better in any way. For information on handling disk-related fault conditions, see the AudioBox Service Manual.

Network Connection

The AB64 communicates with one or more host computers on a local area network via an ethernet connection. The ethernet port operates at 10 or 100 megabits per second, carrying Internet Protocol (IP) packets that conform to the UDP protocol. A CAT5 cable is used to connect the network port on the back of the AB64 to a port on a switch, hub or router. It is also possible to connect the AB64 directly to a host computer's ethernet port using a crossover cable (some computers, e.g. most Macintosh computers, will also work with a normal cable). Cables used must be less than 100 meters in length. Note when using a direct cable connection it may be necessary to turn wireless networking off on the host computer.

The AB64 has its unique ethernet MAC (hardware) address programmed into its ROM at the time of manufacture. The AB64 firmware uses this MAC address with the ARP, DHCP and ICMP protocols to establish and maintain connections with host computers on the local area network using IP addresses. The IP address that the AB64 uses may be assigned dynamically by a DHCP server on the network, manually by the user or by auto-configuration. See the "Network Configuration" section below for information on selecting these options. The AB64 responds to "ping" requests on its assigned IP address.

See the Command Set Document for software details of the ethernet implementation.

MIDI Connections

The AB64 has two standard MIDI ports on the rear panel. Port 1 is a general purpose port. Any MIDI-formatted AB64 command, including standard MIDI continuous-controller commands (for control of submasters from generic MIDI faders) as well as AB64 MIDI Show Control and MIDI system exclusive commands, as documented in the Command Set Document can be received on the MIDI 1 IN connector and performed by the AB64. Commands that originate in cues contained in a 'show' file being executed by the AB64 Show Controller are optionally transmitted on the MIDI 1 OUT connector.

The second MIDI port is dedicated to use with a control surface. The Motor Mix Digital Mixer Worksurface is the only control surface supported at this time (A436 firmware and above). When using a Motor Mix with the AB64 always plug the Motor Mix MIDI OUT to the AB64 MIDI 2 IN connector and the AB64 MIDI 2 OUT connector to the Motor Mix MIDI IN.

See the Command Set Document for software details of the ethernet implementation.

LCD Screens

The second LCD page displays live control signal levels. The first line displays the current state of the ethernet link: NONE, 10 Mb (mega-bit per second) or 100 Mb. The next line displays horizontal meters indicating the level of ethernet receive (R) and transmit (T) activity. The next two lines display meters indicating the level of receive (R) and transmit (T) activity on the two MIDI ports. Disk read (R) and write (W) activity is displayed on the next line (64 channel playback is illustrated above). General Purpose I/O port activity is displayed on the next line. When a GP input trigger occurs, the type of trigger (CUE or PLBK) is displayed for a few seconds, along with the number of the triggered cue. When a General Purpose output is turned on or off, the output (GPO1 or GPO2), followed by ON or OFF is displayed for a few seconds. The left and middle pushbuttons are set up to toggle these outputs for testing purposes.

The third LCD page displays unit information: serial number, internal temperature, firmware revision, current IP address, method by which the IP address was established, ethernet physical (MAC) address, current MIDI ID, and current default show number.

The fourth LCD page is used to configure the network IP address that the AB64 will use. Pressing the TAB button will move the blinking cursor to the check mark next to USE DHCP. The right pushbutton changes to the ENTER function. Pressing the right pushbutton at this point will toggle DHCP enable (which is indicated by the check mark). With DHCP enabled, whenever an ethernet link is established, the AB64 acquires the IP address it will use from a DHCP server on the local area network. It also acquires an IP address at the time when DHCP is switched from disabled to enabled (using this screen). Most routers contain DHCP servers to automatically configure the local area network. With DHCP enabled, the AB64 will try to get an IP from a DHCP server for about 20 seconds. If no DHCP server responds, the AB64 will select an IP address to use through an auto-configuration process. If DHCP is disabled, a fixed IP is used. This fixed IP is entered on the Network Configuration screen and is saved on disk and used every time the AB64 is powered up. Pressing the TAB pushbutton moves the cursor between the digits of the fixed IP. The middle button increments the digit at the cursor (rolling back to '0' after '9'). When the fixed IP has been edited, pressing enter writes it to disk and sets it as the IP address in use by the AB64. The right pushbutton changes back to the PAGE function.

The fifth LCD page is used to set various unit parameters. Pressing the TAB pushbutton moves the blinking cursor to the next line of the display. With the cursor on the first line, pressing ENTER will set the default show to zero (none). INITIALIZE SETTINGS sets most user-configurable settings to their factory defaults, see the CLEAR DATA command ('clear all user data' option). CLEAR DIRECTORIES removes all audio and show files from the internal disk. A confimation screen is presented after pressing ENTER for both INITIALIZE SETTINGS and CLEAR DIRECTORIES. SET ANALOG LOOPBACK is used to active a testing mode in which analog signals are converted to digital and then converted directly back into analog, never leaving the analog circuit board. This is useful for test purposes. In this mode, all analog inputs are connected to their corresponding analog outputs, channel 1 to 1, 2 to 2, etc. If analog loopback is set, the unit setup screen text will change to CLR ANALOG LOOPBACK.

Pressing PAGE on the Unit Setup Screen will return the display to the main screen. Additional LCD screens will be defined at a later time.

This screen indicates a disk error has occurred. This must be resolved before the AB64 can be used.

See the AudioBox Service Manual for additional troubleshooting information.

This screen indicates a system error has occurred. The most likely cause of a system error is a hardware or firmware fault. The unit may be restarted, but the error may recur until the cause is corrected. If the error occurs when a particular command is executed, a work-around may be to avoid using that command until the fault is located and corrected. The exact data on the screen should be communicated to Richmond Sound Design.

See the AB64 Service Manual for additional troubleshooting information.

Audio Connections

The rear panel of the AB64 has a row of four female DB-25 connectors for each installed set of 16 input and output channels (female connectors are used for both input and output channels). Each DB-25 connector carries 8 balanced audio signals. The DB-25 pinout is shown in the chart below.

(Early production units with the following serial numbers use an alternate pinout; click the serial number of your unit for the correct audio connector pinout: 43021001, 43021002, 43021003, 14021002, 15021001, 15021002, 15021003, 15021004, 15021005, 15021006.)

The analog inputs accept signals up to +20 dBu without clipping. Unbalanced input connections are made by connecting either the + pin or the - pin to ground, and driving the other pin. When connected unbalanced in this way, the input signal is boosted by a factor of two by the input circuitry.

Unbalanced output connections are made by leaving either the + pin or the - pin open, and driving the audio line with the other pin. (Shorting the other + or - pin to ground will not cause damage to the outputs, but is not required nor recommended.) When connected unbalanced, the output signal is half of what it would be if it were connected balanced. (The alternative - boosting an output level by two on the driven line when connecting unbalanced - can cause a signal to clip when connected unbalanced that does not clip when connected balanced. This clipping could occur either in the AudioBox output stage or the unbalanced input of the driven equipment.)

Ensure that phantom power is never applied to AudioBox inputs or outputs.

GPIO

The AudioBox AB64 model provides a general purpose input / output (GPIO) parallel contact closure interface for triggering cues and controlling external equipment. The pinout for the AB64 GPIO connector (female DB-25) is provided in the following chart. All inputs and outputs are opto-isolated for reliable operation in a variety of electrical environments. There are eight address inputs, two trigger inputs and two outputs. Each of these inputs and outputs is a two-wire current loop, a signal line and a current return line.

GP Inputs

An input can be activated by placing a voltage on the signal line of 5 to 24 volts DC with respect to the current return line. An input can be deactivated by placing a voltage on the signal line of 0.8 volts DC or less with respect to the current return line, or by opening the current loop. The current loop has an impedance of approximately 4000 ohms. The trigger inputs are locked out following a valid trigger, preventing false retriggering due to contact bounce or noise. (The default lockout time is 1 second, see SET GPI).

When the cue trigger input is activated, the number binary-encoded on the address lines (0..255) is read, and the cue with that number as its major cue number (with all subsection numbers set to zero) is activated. When the playback trigger input is activated, a null playback GO is generated (which will start playback within 1 millisecond on all enabled playback channels), the number encoded on the address lines is read, and the cue with that number + 256 as its major cue number (with all subsection numbers set to zero) is activated. A null show control GO (which activates the next cue) is also available by setting all zeros on the address lines and activating a cue trigger. See the Show Control section of the command set for more details. It is also possible to make the playback trigger behave as a second cue trigger. See the SET GPI command for further details.

GP Outputs

The two gerneral purpose outputs are set on and off via AB64 command (See SET GPO.) They can also be tested from the front panel (see Control Signals.) If on, the output line is connected to the output return line through the output stage of an activated 6N138 opto-isolator (the AB64 supplies 2 mA of forward current to the internal 6N138 LED). The 6N138 is capable of sinking up to 60 mA of current. See the data sheet for the 6N138 for information concerning the maximum currents and voltages and the transfer characteristics of this device.

Recording and Playing Back Audio

Audio Modes

The AB64 is always in one of three audio modes: single channel file playback, multi-channel file playback or record in progress. These modes are mutually-exclusive. Single channel file playback is the most commonly-used and most versatile playback mode (this is the mode that AB1616 and 1616HD models always operate in). Recording more than one channel on the AB64 generates a multi-channel file. The multi-channel file playback mode is provided so that multi-channel audio files may be played back immediately after having been recorded, primarily for verification purposes. Only one multi-channel file may be played back at a time, but the file can contain up to 64 channels. A mutli-channel file recorded on the AB64 may be split into a set of single channel files, which then may be played back in single channel file playback mode like other audio selections. Consult the documentation for the control program being used with the AB64 for specific instructions on recording and playing back multi-channel audio.

Playback States

A playback channel is always in one of three states: 'playing', 'stopped' or 'disabled'. A channel that is in 'playing' state is actively playing back audio from the disk. A playback channel that is 'stopped' or 'disabled' is silent. A channel that is not 'disabled' has a current playback location (i.e. it is playing or is stopped at a specific location). If 'stopped', a channel is ready to start playback. A channel becomes 'stopped' either by having an audio selection loaded on the channel, or by being stopped, manually or automatically, when playback was active on the channel. A channel that is 'disabled' has no current playback location and is not ready to start playback. When the AudioBox is powered on, all playback channels are initially in a 'disabled' state. Thereafter, a channel becomes 'disabled' by playing to the end of a selection, or by specifically disabling the channel. Playback will always stop at the end of a selection, which will set the playback state to 'disabled'. An automatic stop point (one per channel) may optionally be placed at any location. When an automatic stop point is reached, the playback state goes to 'stopped'. Consult the documentation for the control program being used with the AB64 for specific instructions on loading, starting and stopping audio playback.

• User's Manual Contents
• Service Manual
• Return to HFI Home Page