DIYAPASON-L Digest #584 - Wednesday, June 5, 2002
 
Re: [Residence Organs]  Re: sampling rates
  by "Peter Schmuckal" <peter@schmuckal.com>
 

(back) Subject: Re: [Residence Organs] Re: sampling rates From: "Peter Schmuckal" <peter@schmuckal.com> Date: Wed, 5 Jun 2002 20:57:58 -0700   Ah, I was hoping Larry would chime in...   Here's a few more details on my system which sounds similar to Larry's in that each rank had its own processor and the MIDI stream was fed to all = rank board simultaneously. One difference is that the ranks boards themselves contained the complete specification for the rank(s) it was controlling = such that the console only needed to send the actual stop switch positions when they changed. The rank board had to do all the logic of figuring out the specification, coupling, etc..   Again, the idea was to make the console a dumb MIDI controller, and locate all the intelligence at the ranks. This actually makes each rank a potentially independent instrument, though I never got around to fully exploring that implication.   As Larry also mentions, encoding stop changes is problematic since MIDI doesn't have any formalized method to deal with stops. I chose to use the SYSEX route such that any stop change sent a fixed length SYSEX message = that contained a complete bit map of all stop switches, as well as all key states. A benefit of doing this was as a backup in case a Note Off = message somehow got lost, any stop change would instantly re-synchronize all note = (& stop) states in all ranks. If you bit encode the stops and keys, it = doesn't require too many bytes of message.   The penalty for this was, of course, a longer SYSEX message, and a small lag at every stop change. This could be problematic for large organs with several manuals and gobs of stops, but it was not noticeable on the small organ I installed it on.   - Peter Schmuckal   ----- Original Message ----- From: "Larry Chace" <RLC1@etnainstruments.com> To: "Residence Organ List" <DIYAPASON-L@pipechat.org> Sent: Tuesday, June 04, 2002 8:25 PM Subject: [Residence Organs] Re: sampling rates     > Christopher Sabatowich raised the questions of sampling rates (for a > multiplex system for pipe organs), and several folks have made = interesting > contributions on that topic. I'd like to join in, even at the risk of = it > becoming un-interesting! > > ....