Nikolozi: Yes Qithesizer would be a useful reference point, but please don’t stop there! Qithesizer is promising but IMO it is very limited in current form.

Here are some non-iOS examples of Physical Modeling stuff to inspire you:

Jon Diercks: Awesome, thanks for all the links. I'll go through them. btw I wasn't necessarily saying that Qithesizer will be the main influence. I just wanted to capture what the user suggested in the email. That way when I get to PM I'll come to this page and re-read all suggestions made by various users.

Yet another reference video: Erica Synths Steampipe https://youtu.be/4Wm5k_wW548?si=G7x3cSg3pusWRKQR

This sounds amazing, and if I'm not mistaken, it looks like Mela already has most if not all of the ingredients to build an equivalent, or something very close. I’m not 100% clear on how to do the delay lines and feedback loops in Mela, and some of the tweaks like “poloarity” (which he explains is just odd harmonics instead of both odd/even) and “push” (multiplied feedback instead of added?).

Nikolozi, might you be able to comment on anything this hardware device appears to have that Mela might not yet be able to do?

Also very interesting, the user manual for steampipe goes into more detail about the contstruction of the model:

(see especially page 6)

Not sure what they mean by “push/pull” in the feedback loop, but it seems critical for the type of blown model I would be most interested in.

Jon Diercks I haven't fully watched the video yet, will do it when I get a chance.

The first thing I will say is that the (universal) Comb Filter module in Mela can do basic physical modelling, it can do Karplus-Strong. Just set Mode to Pitch, feed it Noise pulse and adjust the Feedback parameter as needed (see the screenshot). Positive feedback will give all harmonics, and negative will give you just odd harmonics. This is what he meant by polarity in the video. In the Comb Filter module, it's a continuous parameter from negative to positive. I made it like that because it's useful when making a flanger using the module, where feedback can be modulated from negative to positive.

Obviously, feedback plays a crucial role in physical modelling. So it would be great if feedback could also include other processes and not just be inside a module. I plan to address this by introducing a Feedback module, so a delayed signal can be fed back anywhere.

As a bonus, I would like to add a sub-lane feature to Comb Filter where the user can insert other modules in the feedback path.

Jon Diercks Thanks for the link I was going to look at the manual as it wasn't clear from the video what Push was doing. Now, I understand, and with the future Feedback module, that will be possible. Feedback plus multiplication (aka Ring Modulation).

Nikolozi - Thanks for that interpretation! A new Feedback module and Sub-Lane for Comb Filter Feedback sounds like just what would be needed to do things like Steampipe is doing, with saturation and HPF/LPF happening inside the loop. And now that you’ve explained that multiplication = ring mod in this context, I need to go back and watch your ring mod videos again. :-)

So would that Sub-Lane feature be implemented by linking the Comb Filter Feedback to a designated Lane elsewhere in the patch, and that would set the Lane’s audio input and output to function as an insert point for the feedback loop?

Another thing about Steampipe’s model that isn’t clear to me is the “split” functionality. The diagram shows two delay boxes in series, and the split is described as splitting the resonator pipe into two different lengths. In Mela woud this require two Comb Filter instances, maybe with a Pitch Ratio module between them? Would the two Comb Filters then send both of their feedback loops through the same Sub-Lane?

Jon Diercks Let me first expand on sublanes features. This is inspired by the Ableton/Bitwig world. The first obvious module with sublanes would be a Stack module, where a module would contain multiple sublanes running in parallel. So, for example, you could stack multiple oscillators with their own filters in parallel. But there are many different types of sublanes possible in different modules. If a module has a feedback path, like a delay effect, the user might be able to insert other modules in the feedback path. I attached a screenshot from Bitwig where the Delay+ device has Saturator and Amp devices inserted in the feedback path (named "FB FX"). I would like to do something like that with Mela modules where it makes sense. The Comb Filter module might be able to do something like that.

Note that I haven't yet figured out the UI that makes sense for Mela, or implemented all the details. It's all a bit theoretical so far. But I think it will work out.

From the manual and diagrams, it's not obvious to me what split does, I'm guessing multiple feedback paths are created. I'll have to look at it closely later. But Mela's future Feedback module should allow you to create fully custom comb filters, and anything that Steampipe is doing should be possible (at least the general circuit should be reproducible).

Nikolozi that sounds great, and very powerful. I agree the UI will take some thought - needs to be visually intuitive for a somewhat complex concept. I'll look forward to trying it!

Woohoo I just saw build 361 drop! Can't wait to try it. Hope you'll be making another mini tutorial video!

Jon Diercks. I hope to make an "Intro to Mela" 6 series, as so much changed since 4.0. And then I'll get into Feedback stuff.

Nikolozi: Thanks! When you do find time to look at PM, I would suggest that, while there are a fair number of PM engines out there that are focused primarily on transient “plucked” or “struck” exciters and resonators, it would be especially cool if something more specifically optimized for sustainable “blown” sounds (wind instruments) was available. The closest thing I’m aware of right now is Respiro, but on iOS that’s really only a patch-player, and most editing must be done on the desktop version of the app.

Jon Diercks: Cool, I'll keep this in mind.