User`s guide

User's Guide HDSPe AIO © RME

In AutoSync mode, the system constantly scans all digital inputs for a valid signal. If this signal

corresponds with the current playback sample rate, the card switches from the internal quartz

(System Clock - Mode Master) to a clock generated from the input signal (System Clock - Mode

Slave). A difference to usual slave behaviour is that when the input signal is lost the card will

immediately switch back to the internal clock, into Master mode.

With the HDSPe AIO all inputs operate simultaneously. However, as there is no input selector,

the HDSPe has to be told which of the signals is the sync reference (a digital device can only be

clocked from a single source).

Via Pref. Sync Ref (preferred synchronization reference) a preferred input can be defined. As

long as the card sees a valid signal there, this input will be designated as the sync source, oth-

erwise the other inputs will be scanned in turn. If none of the inputs are receiving a valid signal,

the card automatically switches clock mode to ‘Master’.

To cope with some situations

which may arise in studio prac-

tice, setting ‘Pref Sync Ref’ is

essential. One example: An

ADAT recorder is connected to

the ADAT input (ADAT immedi-

ately becomes the sync source)

and a CD player is connected to

the SPDIF input. Try recording

a few samples from the CD and

you will be disappointed. Few

CD players can be synchro-

nized. The samples will inevita-

bly be corrupted, because the

signal from the CD player is

read with the (wrong) clock from

the ADAT i.e. out of sync.

In this case, 'Pref Sync Ref'

should be temporarily set to

SPDIF.

RME’s exclusive SyncCheck technology enables an easy to use check and display of the cur-

rent clock status. The status box labelled Input Status indicates whether no signal (‘No Lock’),

a valid signal (‘Lock’) or a valid and synchronous signal (‘Sync’) is present at each of the digital

clock source inputs.

In practice, SyncCheck provides the user with an easy way of checking whether all digital de-

vices connected to the system are properly configured. With SyncCheck, finally anyone can

master this common source of error, previously one of the most complex issues in the digital

studio world.

Thanks to its AutoSync technique and lightning fast PLLs, the HDSP is not only capable of han-

dling standard frequencies, but also any sample rate between 28 and 200 kHz.