Akai dps24 ADAT AND DIGITAL CLOCK

With only the standard 8 channels of ADAT I/O, the DPS24 can send its master FX/AUX

sends to the ADAT outputs and use the computer as global loop effects.

But with the IB-24ADT option board, the DPS24 can send simultaneously its 24 tracks to the

computer for individual track processing.

In any case, effects returns from the computer via ADAT input can be assigned to the four

stereo FX Return channels, and/or to any available input channel.

However, if you do plan to embark upon this, you must read the other equipment's docu-

mentation carefully to establish that what you want to do is technically and practically pos-

sible. There should be no problems - the ADAT interface is a well-known and popular one

that is (or can be) fitted on many pieces of digital equipment - but please check carefully.

ADAT AND DIGITAL CLOCK

When using the ADAT digital I/Os, it is critical to make sure that the digital clocks of the DPS24

and of the other ADAT units are locked, but it is also important to be careful not to create clock

feedback loops. Incorrect clock setups will result in digital glitches or digital noise.

In normal operation of an ADAT system, with the ADAT SYNC OUT of the IB-24ADT connected

to the ADAT SYNC IN of the ADAT system, the DPS24 Digital Sync parameter should be set to

INTERNAL, as the DPS24 is the master of the system. In this configuration, the ADAT machines

are locked together to the clock of the DPS24 via the ADAT SYNC connection.

If the ADAT SYNC connection is not used, it is possible to either lock the ADAT devices to the

DPS24 master clock (DPS24 Digital Sync still set to INTERNAL) via the ADAT lightpipe (the

ADAT devices should be set to clock from their optical input) or via Wordclock (the ADAT de-

vices should be set to clock from their Wordclock input) .

It is also possible for the DPS24 to slave its clock from one of the ADAT optical inputs.

When the IB-24ADT board is installed, two additional options are available for the Digital Sync

parameter in SETUP mode: "ADAT 9..16" and "ADAT17..24", in addition to the "ADAT 1..8" op-

tion. In this case, the selected ADAT clock source device should be set to its internal clock and the

other units should be locked to the master ADAT unit.

Finally, it is possible to clock the entire system from an external Master Clock unit (Sync/Clock

Generator/distributor), typically via WordClock. In this case both the DPS24 and the ADAT de-

vices should be set to WORDCLOCK digital sync.

At no point should the DPS24 and the ADAT system be both set to clock from their digital inputs

at the same time. This would create a clock feedback loop (the DPS24 trying to sync to its digital

input while the connected source is trying to sync to the digital output of the DPS24).

v1.6 Operator’s Manual