Thanks for your post!
Okay, test2 works if I replace the direct feedback path with send~ and receive~ objects. I understood that test2 fails since there is a signal path from the output to the input of the same object, which is delayline~, Whereas with test1 the feedback path is connected from delread~ to delwrite~, i.e. there is no object with a path from its output to its input.
test1 realizes a simple delay effect. test2 is identical, but the delay buffer is encapsulated in delayline~. test1 works fine, but with test2 a DSP loop is detected. I'm wondering why. Is it a bug or is it defined behavior? I'm using Purr Data 2.19.3 (Pd-0.48.0) and also tested it with Pure Data 0.52.1.
Thank you in advance!