FV-1 delay without pitch modulation when changing delay time?

[tjpascon]

Hi everyone,

I’m fairly new to FV-1 programming and I’m trying to understand something about delay algorithms.

Whenever I change the delay time on the FV-1 while audio is running, I always get the typical pitch glide / pitch shift caused by the read pointer moving. I’ve been searching around but couldn’t find a clear explanation or an example showing how to avoid it.

My question is:
Is there any reliable method to implement a delay on the FV-1 that does not produce pitch modulation when the delay time is changed?

If anyone has done this before, or knows whether it’s possible within the FV-1’s limitations, I’d really appreciate any tips, references, or code examples.

[frank]

You could wait to change the pointer until after the user stops moving it then jump to the new point but you will hear a discontinuity in the sound and the user will feel a delay in changes. So comes down to do you want to hear pitch shifting or glitches?

[Digital Larry]

You can detect changes in the delay time pot and use this to fade up/down two separate pointers. You have to have some sort of limit/hysteresis so that you are not changing the tap point of the delay while it is faded up. I don't have any examples, it's pretty complicated, but I have seen it done.

DL