delay-with-feedback question

Question

hello, 

i just experimented with the 10 taps sound from the kyma lib - with randomdriven pan and delay of each instance. but as soon as i try to change the parameter DelayScale on the fly it results in a up or down pitched-like effect. i guess this due to the internal programming of the delay prototype. 

is there a workarround to get unpitched transitions when changing the parameter DelayScale?  i know that i can deactivate SmoothDelayChanges but this results in clicking when changing the parameter. 

any ideas? 

for demonstration i append 2 sounds. 

thanks, johannes

Answer 1

As you've noticed, the DelayWithFeedback does a smooth transition from the old to the new delay and as a side-effect, the distance between waveform peaks increases or decreases resulting in an apparent pitch change (same principle as a Doppler shift). If you remove the smooth transition, you drop the current contents of the delay line and instantly change delay time, but there can be a click due to the consequent discontinuity in the waveform.

One solution would be to use the smooth transition but to mute the audio output while the transition is occurring.  For example, you could attenute the output at the same time you change the delay time, and you could bring the levels back up after the old signal has been cleared from the buffer and the new delay time is stable.

Another, related solution would be to turn off the smoothing and briefly attenuate whenever you change the delay time to smooth over the discontinuity when you do an instant delay change and empty the buffers. Here's an example.

Comments

thanks ssc, interesting…i also thought about something similar.
the next step would be to fill these muted holes when changing the delay parameter. but at the moment i have no idea how to do that. maybe by a crossfade between 2 groups of 100 taps?

in the meantime i also worked on a midivoice version but using this module its more difficult to simulate the individual taps timing. will report back later on weekend.

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with midivoice it works as well. but for quick layering and ambience stuff in protools i will use grm-delay for now.thanks

Answer 2

Have you ever tried DriftingSampleCloud from the Gallery (check the Manglers box)?   It seems to yield a result that is similar to the random multi-tap example you attached. If you set !Direction to 0, you can change !ReverbTime without affecting the frequency.  And you have a lot of other parameters to tweak, like !GrainDur. You can change the range of !GrainDur to be larger than (0,1) by ctrl+clicking on the widget and selecting Change Range.

Comments

thanks ssc. could you please point me to where i can find the sound in the kyma-lib.

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Easiest way to find it: open a sample in Wave Editor, use the side bar to create a Gallery (Check the Manglers box) then press Gallery.   You will find it in the Manglers category.

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I love this idea of thinking about a Sample granulator as a delay line. If there were ways to trigger the grains individually with specified delay offset times and even filtering per grain that would be pretty nice... Inspired to build that Class soon at the NeverEngine Labs....