Output latency, midio128 driving pipes as soundsource in jorgan

[John_W._Couvillon]

This is a joint situation inbetween MBHP and jorgan.

My organ project is nearing the end of the line and this is a rather unexpected problem.

Organ setup:

midified console utilizing two midio128 programmed cores as key encoders for 2 manuals, pedals and stops.

PC running jorgan running version 2.3, with USB/ midi interface. ( midisport 2x2)

two midio128 cores with dout/uln2803 drivers programmed as outputs driving pipes.

Problem:

With jorgan running with key encoders,  no problems at all with any soundfonts, etc. etc.

with jorgan running with key encoders, and the USB interface/midio128s set as the external soundsource, all pipe drivers functiion individually, no problem.  with a jorgan electronic stop selected,  both the pipe and the electronic pipe sound together, no problem.

However, the more notes that are played simultlaneously, the more the latency builds.  With two five note chords and a single pedal note playing the latency is 1 to 1.5 seconds.

Troubleshooting already done:

Checked the wind system for the pipes to ensure regulation.  wind pressure does not vary from 3"wc.

Checked power supply regulation on the  uln2803 driver supply.  Voltage is 18vdc steady state, drips to 16 volts with 11 outputs open at one time.

Issues that may have a bearing:

the ouput cores are daisey chained.  One of the cores has the same id as a core in the encoder side of the system, although the pc and jorgan are between.

It appears that the jorgan electronic sound can be heard ahead of the actual pipe sound when 11 notes are played. However, with only one pipe sounding, there is no latency and the notes sound together.

Help!

Johnc

[John_W._Couvillon]

Another titbit of data:

Connected the midi out of the keyboard encoders directly to the midi in of the pipe decoder cores and experience no latency at all.

Evidently the latency must be coming from jorgan. 

Any comments from any of you jorgan users?

Thanks,

Johnc

[doc]

Hi,

midified console utilizing two midio128 programmed cores as key encoders for 2 manuals, pedals and stops.

PC running jorgan running version 2.3, with USB/ midi interface. ( midisport 2x2)

two midio128 cores with dout/uln2803 drivers programmed as outputs driving pipes.

Just a thought I want to report to you...

I don't know jorgan, but I know midisport 2x2. In several forums (e.g. steinberg.net) users report latency (and other) problems with the midisport 2x2 USB Interface. Just a hint. If you have the possibility, try another USB-Midi Interface. Perhaps the latency proplems are gone then.

greets

Doc

[stryd_one]

try another USB-Midi Interface.

That's a good point, those interfaces are reputed to be pretty dodgy... Better yet you could try a non-USB MIDI interface - Latency problems are inherent in USB's design but fortunately usb2 is fast enough that the overtheads often make the timing issues transparent....but not always...

[TK.]

John mentioned a latency of 1..1,5 seconds, this is not caused by the MIDI interface - the midisport 2x2 has a latency and jitter of about 5..10 mS +/- 1.5 mS (see also http://www.midibox.org/forum/index.php?topic=2342.0)

So, it's more likely that the software causes the high latency - another MIDI interface won't help in this case!

Best Regards, Thorsten.