[QLab] Primary and Back Up Set up.

[Andy Leviss]

On Nov 4, 2007, at 9:33 AM, Noah Mehl wrote:

> In the theatre world, you would check the system before opening the
> show.  If it doesn't work, you'd copy the show files to the backup
> computer.  Pre-show checks allow for enough time to do that.  Plus,
> the possibility of a catastrophic failure during a show is very, very
> low.

Low is still too high, and for the record, I've never seen it done  
this way in my experience with off-Broadway, Broadway, and national  
tours. SOP on these shows (including the ones I'm aware of from other  
colleagues on the West End) is that the show is designed on the  
primary system, and then once the show is programmed, the show is  
copied over to the backup. Both systems are triggered via some form  
of external MIDI that's split via a MIDI Devices Quadra-Thru or  
something similar, and a suitable audio switching (and MIDI, if  
necessary) system is put in place to handle changeovers. Standard  
used to be a BSS Soundweb analog switcher, now it's common to see a  
Frontier Apache ADAT switcher, with ADAT to analog converters if  
needed. Playback is synced via external wordclock, and running ADAT  
through an Apache into a Yamaha digital console, the switching is  
absolutely seamless, you can switch back and forth all day long and  
nobody will hear it. It's kinda a thing of geekish beauty :-)

--Andy