The attached patch "should" produce a bandlimited square wave at 523.2 Hz (using the sawtooth/delay/subtract trick). But the oscilloscope array shows a smaller-than-expected pulse width.

I think my math is right: delay time in ms = 1000 / freq * pulse width. But the delay time is slightly off from where it should be.

I'm pretty sure, if I do the same with SuperCollider's Saw and DelayC units, the pulse width renders as expected. So I think there is some inaccuracy with delread4~'s delay time. Or something else?

19-0902-pulse-wave.pd

hjh

@ddw_music Hi, what is actually the issue here is that the block size is 64 and the delay objects aren't aware of their execution order, therefore the delay time can go no lower than 64 samples (~1.45 ms @ 44.1 k). If you always have the reader after the writer you can utilize the technique in audio example 3.audio.examples/G05.execution.order.pd to get the objects to know that the writer is after the reader. Alternatively, you could put the writer and reader in a subpatch with lower block size.

@seb-harmonik.ar Thank you! It took me a long time to get around to this, but I finally put the reader and writer into subpatches and indeed, that sorts it. Thanks!

hjh