thanks for the explanation! that mostly makes sense, I'll check out those audio examples.

I'm using send~ and receive~ in the abstraction, and I thought that even if the abstraction were instantiated into a different PD patch, the send~ and receive~ objects would still do their thing. It seems like having them inside an abstraction is what is making the feedback not work, and that's the part I don't understand. In my mind everything should function exactly the same whether it's inside an abstraction or not.

Some pictures to illustrate:
Inside the VCO abstraction the input and output goes through s~ and r~ objects

..and if I use s~ and r~ objects outside the abstraction it works:

But since there are already s~ and r~ objects inside the abstraction, I would think this would work.. but it doesn't.

I'm sorry if I'm just fundamentally misunderstanding this! Thanks for your help!

hi all! long time lurker/reader, first time poster. thanks for sharing all your knowledge, it has been invaluable to my education in PD!

I'm building a sort of modular synth in PD and have arrived at an issue: feedback. I've search this (and other) forums and found that feedback is possible if one uses send and receive objects, and indeed this works... sometimes.

Each of my modules exists as it's own PD file - I think that's called an abstraction. I have them set to "graph on parent" so there is a little GUI/module front panel that can be manipulated. When I instantiate a module, such as an oscillator, it works great but if I route the output back into the input (through a *~ object or something) I get the "DSP loop" error. I have a block~ object in the abstraction set to 64 (block~ 64) per some instructions i found in this forum.

However,** if I am "inside" the abstraction** (if I open the abstraction file) I can successfully connect the output of the oscillator (from a r~ object) back into itself (into a s~ object).** The patch feeds back** and it sounds awesome!

I don't understand why this feedback works inside the abstraction but not when I'm "zoomed out" (I'm not sure what the terminology is). I suspect I'm missing some key piece of understanding.

If anybody has any ideas, I'd be grateful! Once my little modular system is a little less buggy I'll share the whole thing on github and here.

Here is the oscillator abstraction:
vco.pd