Owner's Manual

16
Using the ADAT connection
In addition to the eight analogue inputs, the Scarlett 18i20 has an OPTICAL IN ADAT input port which
can provide an additional eight audio inputs at 44.1/48 kHz sample rate or four at 88.2/96 kHz. Note
that the optical input is disabled when sample rates of 176.4/192 kHz are in use.
Using a separate 8-channel microphone preamplifier equipped with an ADAT output – such as the
Focusrite OctoPre MkII – provides a simple and excellent method of expanding the Scarlett 18i20’s
input capability.
Computer
running DAW
and
Focusrite
Control
Inputs 1 & 2 on front panel
Optical ADAT connection (TOSLINK)Wordclock link
Inputs 1 & 2 on front panel
Up to 16 Mic/Line Sources
OctoPre MkII
8ch Mic Amp
The OctoPre MkII’s ADAT output is connected to the Scarlett 18i20’s OPTICAL IN port with a single
TOSLINK optical cable. To synchronise the two devices over ADAT, set the clock source of the OctoPre
MkII to Internal and that of the Scarlett 18i20 (via Focusrite Control) to ADAT. Alternatively, stable
word clock synchronisation may be achieved by connecting the Scarlett 18i20’s WORD CLOCK OUT
to the OctoPre MKII’s WORD CLOCK IN and setting the OctoPre MkII to use Word Clock as its clock
source, Focusrite Control clock source should be set to Internal.
TIP: When interconnecting two digital devices by any method, always ensure that both are set
to the same sample rate.
The additional inputs realised by use of the ADAT port may be routed using Focusrite Control in
exactly the same manner as the other inputs. The additional inputs can form part of any musician’s
headphone mix, as required.
If a suitable ADAT “break-out” box is available, the OPTICAL OUT ADAT port may be used in the
opposite manner; for example, additional outputs from the DAW may be converted into the analogue
domain to allow the use of an external hardware mixing console to mix down a large number of DAW
tracks.