wevans@elec.gla.ac.uk

I have a mono sample-playback patch that has been built as a stand-alone application. I am observing a curious performance phenomenon between it's performance on my PowerPC and (Mac) Intel machines.

My patch needs to change samples very rapidly and precisely according to incoming data. Specifically, incoming MIDI notes are held (in the patch) until the next note enters. The desired effect is a continuous sound.

On my ancient PowerPC Dual 1.8GHz G5, it works very well. (Tip o' the hat to the Max engineers!)

On my two Intel Mac Laptops, there are very short (silent) gaps between the notes. I can't hear them, but all the trained musicians I'm working with can.

Does anyone please have any thoughts on this?

Specs: All machines are running 10.5.5 with sufficient RAM and identical Firewire audio/midi interfaces. (I tried a different MIDI interface and built-in audio on the Intel machines; there was no difference.) In the patch, Overdrive with interrupts is on (though I tried combos); vector sizes are set to 128. (Are these settings all carried over into the built app?)

Below is the patch; it will not produce sound without its samples. I'm guessing, though, that folks (if so inclined) would simply want to look at the patch. (Please let me know if otherwise.)

As always, thank you for your consideration.

Mac PowerPC vs Intel Stand-alone Issue