Digital Delay - Infinite Repeat w/o Self Oscillation?

[ashcat_lt]

This may not be the right board for this question, but it's the only one I actually read on this forum...

I guess I'm not even really sure how to articulate the question. 

With a digital delay pedal like my Boss GigaDelay, if I turn up the Feedback/Repeat control all the way and hit a note it will repeat that note at the same volume indefinitely.  Then let's say I play a repeating figure over this.  The new input will start to add together and "push down" the original repeating note.  The total output never really gets any louder, but the new input gets louder in proportion to the old input.

OTOH - Using a VST delay plugin, it seems to be very difficult to dial in the feedback parameter to a point where it does infinite repeat without breaking into self oscillation.  At one setting the repeats will eventually die out (though it may take a long time), but if you turn it up just a touch more the repeats get louder and louder.  That's great fun and all, but...  It also seems that if I get something going in a long repeat and then add more input, the total output of the delay just keeps getting louder.  The new repeats are added on top of the old repeats, rather than "pushing them down".  Worse yet, the point where the feedback becomes uncontrollable is hard to define.  It seems to be different for different plugins, and even for different sources with the same plugin.

So, what's the difference?  Is this a function of the "compansion" in the Boss pedal?  Is there any way to get a generic VST delay to react the way I'd expect from my pedal?

[slacker]

My guess would be that the Boss is completely digital so when you turn the repeats up all the way it either copies the output exactly back into the input of the delay or it just repeatedly plays what ever is in the delay, so there's no degradation of the signal over time. The VSTs you're using are probably designed to emulate analogue style delays so can't do continuous looping.
Sorry that doesn't help at all.

[defaced]

If you have the pedal handy, I'd be tempted to patch the signal out to the pedal and use the pedal as the effect, not a VST plugin.  Think of it as re-amping, but instead you're using an effect instead of an amp.