thebiglongy
Not sure if this is possible but....

Is there a way to use a step sequencer to turn on and off the delay on the notes you require? Obviously you may have to create multiple patterns to get the job done?

Or possibly record automation of the on/off of the delay? or dry/wet.

That's basically the same as automating the send level to a delay bus. It would work on notes that have a short decay, but if they sustain over each other then you're going to be choking off some of the tails.

If you are using Rapture or DimPro and are only relying on one single element, then you could set it to Multitimbral mode and copy & paste the element setting to Element 2 and add the synth's own built-in delay effect.

 
Or Lo/Hi Key to create zones in each Element without using multitimbral and MIDI channels.  If the notes are in a narrow range, it may only take 2 or 3 Elements.  If they're isolated and scattered, you may need a few more copy / paste operations, plus the key range adjustments.  In .sfz, it'd only be a few lines of text.

I have not used prizm.  I can see where having a second instance would not be desirable.  Those are great suggestions for those who mentioned using the effects based on elements within Rapture or Dim Pro.  DOes Prizm have similar routing/fx options?

I"m not on X3, but I've never had that particular problem.  It seems the effect isn't being allowed to finish out, which doesn't make sense to me.  In my old dinosaur version of 7PE, you could "play tails", but that typically was when you stopped the song and the tails of effects would still play out.
There seems to be something else happening that is preventing that in your scenario, as you ought to be able to have an automation envelope, to control your delay send, that doesn't cut off the effect, when it is back to zero again... MIDI or audio....either or...


Having two instances of a VSTi, doesn't seem like the solution, as like you said, it eats up available CPU.

dubdisciple
I have not used prizm.  I can see where having a second instance would not be desirable.  Those are great suggestions for those who mentioned using the effects based on elements within Rapture or Dim Pro.  DOes Prizm have similar routing/fx options?

 
I should think some Reaktor whiz would be able to answer that one...I'm not so good "under the hood" of Reaktor though. I should imagine you'd have to get deep into the structure of the synth itself and mess with inputs and MIDI channels though. 

MIDI option 1: Put the notes in a separate track and use the MIDI delay plug-in.
MIDI option 2: Create a number of tracks equal to the number of repeats you want. Copy the notes and paste in one track, then paste and offset in the next track, paste and offset in the next track, etc. Change velocities on the subsequent pastes then bounce them all together. Con: Takes more work. Pro: Sometimes you can get really cool delay effects if the velocity level changes rather than the output level...depends on the patch. This also allows for polyrhythmic echoes.
Audio: Split the clip before the notes you want to echo, then insert a delay effect in only the clip with the notes you want to echo. Note: if the delay tails need to extend beyond the clip, you'll need to lengthen the clip for the duration of the delay you want reproduced.

Why am I able to use an automation envelop to accomplish the same in my older 7PE?
 
btw, Craig's audio version idea is great, as you can "doctor up" the repeats, only limited by your imagination... i.e.  EQ, reverb, volume, and repeat spacing can potentially be more interesting via rhythmic ways.

Anderton
MIDI option 1: Put the notes in a separate track and use the MIDI delay plug-in.
MIDI option 2: Create a number of tracks equal to the number of repeats you want. Copy the notes and paste in one track, then paste and offset in the next track, paste and offset in the next track, etc. Change velocities on the subsequent pastes then bounce them all together. Con: Takes more work. Pro: Sometimes you can get really cool delay effects if the velocity level changes rather than the output level...depends on the patch. This also allows for polyrhythmic echoes.
Audio: Split the clip before the notes you want to echo, then insert a delay effect in only the clip with the notes you want to echo. Note: if the delay tails need to extend beyond the clip, you'll need to lengthen the clip for the duration of the delay you want reproduced.

 
I've actually been having great fun with #2 since last night. The creative possibilities are much better than just using a conventional delay setup. For instance, you can apply a delay to the second track that's not necessarily the same time value as the gap between the first and second lines. So the second track might be offset an eighth note from the first, but you apply a dotted eighth delay to the second track. Or anything you want. Also, you don't have to treat the second track as a "delay" at all times. At select parts you can use it to harmonize the first track. Or you can make the notes of the "delay" slightly different, e.g. apply a little flourish or ornamentation to a chord that's in the first track. If you have both tracks up on the PRV and lock one of them, it's really easy to compose intricate lines that delay, ornament and interweave with each other. And since the "delay" track is a whole new instance of the synth, I can mess with the patch a little bit to get a different sound. For instance since I'm using Prism, I can apply a little feedback to the second track, or mess with the attack or impulse settings. From initially just wanting to apply delay to certain notes, I'm now weaving two separate but related lines around each other. I love how technology inspires creativity like this. 

stutter FXs??  :-)