I also have the VintAudio Yamaha C7 and have used it with G3 with no problems. I think all I did was to load one of the .gsp files and it did everything else on its own. I am not at my G3 computer now, but I seem to recall that it load files to a couple of linked ports. I didn't have to do any manual stacking.
I've noticed crackling on stacked tracks as well. I loaded up the 24 bit VGL ensemble sustain samples for violin, viola, cello, and bass on a single stacked channel to do some tests with GP. Before inserting GP I played the stacked samples on the virtual keyboard. Sure enough, snap, crackle, pop! When played from my Yamaha S80 same problem. After unloading two instruments, it seemed to work okay, three got more sketchy, with intermittant snaps, and four + got unworkable.
I'm using a P4 2.4 with 1 Gig of RAM, and accessing midi via a Delta 1010.
I was getting the crackling in various instances- esp. with my GPII and Bosendorfer libraries, but also other instruments, usually happening when GPulse was active.
I did a clean install of WinXP and now the crackling is totally gone... so far. And I'm able to use GPulse and stacking until smoke comes out without any problems
Okay, I think I figured out my particular crackling audio situation with stacked instruments on one channel. When I load a single instrument, the default volume is set to 90. However, when I continue to add additional instruments to that channel, the new drop down box shows each individual instrument's volume defaulting to 127! (the maximum!)
So in my case at least it seems to have been an audio headroom and clipping issue -- attenuating the volume for each track down to 90 or so completely eliminates the crackles and pops. You can control the overall volume of the stacked instruments with the first ('stacked instrument') volume control, but this won't in itself eliminate the crackles. In my case, the clipping seems to be a 'summing' issue of each stacked instrument, especially with the output volume of each maxed out!
I'm not sure if it is a GS3 bug that each instrument's volume ends up at 127 after stacking, or if it is designed that way so that you get a 'proper' output volume from the entire stack, but I thought I would make the rest of you aware of this possible solution at least.
Ahh. That makes sense. I've been going stacking crazy on my little AMD box with no problems - except clipping which I remedied with the volume knob. I hadn't considered that was what you guys were talking about.
The same can happen with GigaPulse - both in the DSP section and embedded. Some of the impulses have gain right out of the box. I did some drumming recently with Larry Seyer's drums (the whole kit was stacked). I did a capture dry, and with each of the three embedded impulses. Even though they sounded fine, when I opened them in Vegas I found that they were clipped to death. I had to drop the volume by about 10 dB to get the whole capture in range for the Thunderous impulse. Unfortunatlely, the output meters in GS3 seem a little slow - they don't show overloads clearly.
So listen for digital clipping, and inspect those waveforms. Drums may sound okay with their peaks clipped (compression anyone?), but orchestras like headroom.