Channel Digital Output Option; Digital Outputs (Aes, S/Pdif); Jumper Position; Aes, S/Pdif Switch - Focusrite ISA428 MkII Mode D'emploi

8 Channel Digital Output Option

The optional ADC can be retrofitted to a standard ISA428 MkII at any time. No engineering experience is required as the card can be
fitted easily by the user. Full fitting instructions for this option are included along with the ADC.
The ISA428 MkII can be used as a high quality 8 channel ADC for analogue transfer to digital with the addition of the optional digital
output board. The 4 external ADC inputs and the main channel inputs can all be fed to the ADC, ensuring eight super-clean, high-
quality paths to digital. A single ISA428 MkII unit can act as an 8-channel digital input expansion unit to any DAW. Channels 1-4
always route respectively to ADC output channels 1-4.
Alternatively, two ISA428 MkII units with a single ADC option can be used to create an 8-channel mic pre to ADC system. Digital
formats available on the ADC are AES/EBU, SPDIF and ADAT™ optical format.

Digital outputs (AES, S/PDIF)

A 25-pin (Tascam DB-25FM) connector allows up to 8 channels of 24-bit digital audio (AES or S/PDIF) to be transmitted to a DAW or
other digital storage medium. The card can be configured using jumpers (on the card) and using two push button switches on the
rear panel. The table on page 10 shows the pinout details for all available configurations. Below is a brief description of the overall
functionality available.

Jumper position

The digital card has four jumpers (movable plastic clips) that can be positioned so as to disable AES outputs 5-8, and therefore make
the ISA428 MkII pin to pin compatible with a Pro Tools HD™ 192 interface using a standard 25-pin to 25-pin cable. With the jumpers
in the disabled position (default), channels 1-8 are available at 44.1-96kHz and channels 1-4 at 176.4/192kHz. Depending on the
position of 1-wire/2-wire switch. (See Appendix 1 for details of the cable pinout for recording all 8 channels to Pro Tools™ at 192kHz
- jumpers are in the enabled position in this case.) (See Appendix 2 for details on adjusting the Jumper positions.)

AES, S/PDIF switch

This switch selects whether the signal is professional (AES) or consumer (S/PDIF) digital format. With the switch out, channels 1-8
are in AES format and are duplicated across the connector, allowing 16 outputs (dependent on wire mode switch). With the switch
in, channels 1-8 are available as S/PDIF and AES formats (number of channels available in AES format is dependent on wire mode
switch). See the table on page 10 for pinout details.

1-Wire/2-Wire AES mode switch

For sample rates from 88.2 to 192kHz, a dual-wire mode is available for connecting to older equipment with AES
inputs, which can only receive speeds up to 192kHz by using both digital channels of a single AES connection (known as '2-wire').
Engaging this switch 'splits' the digital signal and activates dual wire mode, which means that half the number of channels are
transmitted down the same number of wires. Transmitting channels 1-8 in 2-wire mode requires all of the pins of the DB25
connector. Therefore, if the S/PDIF mode is selected, only channels 1-4 can be transmitted as AES format. (See the table on page 10
for pinout details.)
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