[LAD] Is it possible to use two RME cards in sync?

[Pau Arumí]

El dl 10 de 05 de 2010 a les 17:32 +0200, en/na Florian Faber va
escriure:
> Pau,
> 
> > the system i need to build should have 8 AES inputs and 24 AES outputs.
> > For that, i see two basic approaches 1) using two RME AES-32 (*) cards
> > in world-clock synch and 2) using a RME hammerfall with 24 ADAT
> > input/outputs and then several 8ch ADAT<->AES converters such as the
> > Aphex 144 (+), which costs about 400€ each 8ch unit.
> 
> 3) a MADI interface and any MADI-to-ADAT converter you want

Right. But the MADI-to-AES alone (the ADI-6432) costs about 2800€. Far
beyond 1) and 2).

> What are those AES ports needed for anyway? I mean, this are 16 channels
> in and 48 channels out. With that number of channels, using AES just
> becomes a pita. Think of the cabeling alone - or use Tascam-style 25 pin
> DSUB connectors.

Yes AES makes it all over complex but it is a requirement not a
decision. It is all about connecting to existing boxes.

> > Option 1 seems to me simpler and cheaper but i ignore if is feasible and
> > reliable: Have anyone had good experiences using two clock-synced RME
> > cards with jack?
> 
> The driver can start the buffers synchronously, so you have
> sample-synchronous output. To have jack working with multiple cards, you
> can either use alsa magic to combine the cards, or use alsa_out (with
> disabled resampling).

Will try that with a couple of hammerfall 9632 we have in the lab before
buying the (two) AES-32. 
Any recommended documentation or advice? 
(Apart from this: http://alsa.opensrc.org/index.php/TwoCardsAsOne)

Thanks
P