I turned off “Tape” because I don’t want the delay pitch to change when the delay time changes, however now I’m getting really obvious scratchy and harsh distortion when I change delay time on the Octatrack while audio is playing.
This makes using scenes to change delay time almost unusable.
Is this normal? Or some setting I’ve got wrong?
Yes, that’s expected behaviour - when you switch off tape mode you’re essentially turning off delay line interpolation. You’ll hear artefacts when changing the delay time that may or may not be desirable, the same way you may or may not want the pitch to change when tape mode is on.
Thanks for confirming 
Would be nice if there was a way to change the delay time without things getting distorted.
Even just for experimentations sake, could try utilising slide trigs and see if that provides some smoothing or other interesting results
I’ll give it a try tomorrow.
Messing around with delay time on the Digitakt and Digitone doesn’t seem as bad. Also can change the delay time while audio is playing without issues in a bunch of VSTs.
Here is a video showing what I’m talking about.
Track 5 has the delay time the same and the scenes changes the send.
Track 6 changes the delay time slightly, and the send.
About 20 seconds in the noise gets bad.
For what it’s worth, here’s how I was expecting changing the delay with audio playing to work
Your koala example shows 2 things.
1-Koalas tempo synched delay has very low feedback and hardly any send.
2- much slower time modulation.
Try playing the OT delay the same way and see what you get.
Also, use the filter on the delay. Filter out the low freq.
Not saying you’ll get identical results as koala, or other delays, but you can reduce the unwanted noise in your example.
Remember, there are no fx presets on the octatrack, you have to make them yourself. The delay doesnt work like a delay pedal, which has been tweaked for guitars for example.
Many digital delays work this way.
I can’t think of one that doesn’t
I tried Delay Tape off for a (very) little time while in order to plock delay time changes, and came to the conclusion I much prefer Tape on inconvenient effects…
It was a long time ago…I’d be happy to hear intersting uses of Delay with Tape off.
Leave tape on.
Sync off.
Tune time by ear.
This is the way.
4ms dual looping delay
Old school way ? 
With OT delay tape on, I like very slight lfo variations on delay time, not abrupt ones, unless I want something messy with resample feedback…
So for clean transitions, I’d rather plock delay send and/or level to 0.