I did some more looking into the sound of the 808 Vs 909 and yeah, I can definitely see the appeal in having both. I understand why the page says “[…]simulate the sound of an analog circuit based on classic drum synthesizer hardware” instead of outright saying it’s a 909, but I wonder if that will cause confusion for others like it did me.
I’ll probably end up grabbing these at some point.
Vult never directly references the original. that’s based on all the previous filters and oscillators. so shrug?
I don’t think it’s an unusual approach at all, it happens all the time (I’m thinking along the lines of behringer or vsts which model particular hardware). I think the description carefully avoids saying it is one specific device so it is almost expected to be both or a mix of 808 and 909, and it seems there is a lot of scope to go between and beyond with these modules. I’m not sure that anyone buying a ‘classic drum synth’ plugin or module would be confused if it turned out to be only one or the other, or a mix of both.
It does say though for the Kick there’s 808 and 909 options and the Snare and Clap are based on the 909 models.
Over the years, I have stated my approach of modeling to this community but I will reiterate it for new members. When doing a model, my first step it to create an over detailed simulation model in order to try to capture the sound of the original as close as mathematically possible. Once I have that over detailed model, I start making optimizations by removing the parts that are complex and have little impact to de sound. The next step is to play with the model or my custom circuit in order to personalize or “fix” quirks of the original, basically modding the thing. Last step is to create the DSP code.
In the case of the drums, the careful looker will see that these are not exact 909 drums, starting with the fact that these have more controls than the original 909 drums. These are my modded circuits. I always avoid using the word “emulation” because that’s implies that if you get a 909 and you compare the sound of mine it must sound exactly the same. But that will never be the case. Even my two snare boards that are made with the same components sound different. This is in part due to the tolerances of the components and the differences in the semiconductors. I have some measurements that I will publish at some point.
In conclusion, if you would like to have a version of the drum machine that I would have made in the 80’s, this is it. The analog drums are based on the 909 circuits but they are modded versions (check specially my Rim and Toms). The cymbals are custom and the 808 kick is modded as well.
Most instruments of the Drum Machine sounds very nice for me. (Inc. Kick and Tom.)
A 3 HP extender module with 10 solo output would make the Drum Machine even more practical. But i’s all wishful thinking I assume 
You can send the feature request to Andrew. He is in charge of the UI.
should make it hardware too pls!
Could you provide some insight on this by chance? I’m working on a hardware analog drum machine for my capstone project at my university, and most simulation software we’ve used is really not reproducing the same signals as the circuits built in hardware - for example, most noise gen circuits simulate to a DC offset.
I’ll take this one step further, @modlfo–can you write a beginner-to-advanced book on hardware modeling and DSP? If funds would yield time to do so I think a Kickstarter/Patreon/whatever could raise a substantial amount of money for that up front.
Would this beginner have a solid foundation in differential equations, the z transform, linear algebra, etc? Ok, joking a bit, but this would be a series of books, I think.
This is a good point 
Off-the-cuff: “beginner” meaning comfortable with JOS 1 and 2. I’d file the @modlfo hardware modeling book next to JOS 3 (physical) and 4 (spectral) as peers.
I don’t know if I’m completely comfortable with all of Mr. Smiths papers! So basically you mean graduate student in dsp?
Vega glares at Oppenheim’s “Signals & Systems” and shudders as he recalls many difficult quizzes
I’m taking a DSP course right now, and while it’s more into level (we’re still going over basics- playing around with how discrete convolution and Fourier transforms work) I do have prior experience that means I get these concepts really well while still finding the math difficult. While Mr. Smith’s pages are fantastic, I think largely my problem is so many textbooks (and most lectures) lack demonstartion along side the content. I want to hear things. I want to experiment with parameter changes. (and not in Matlab… god I hate MatLab’s syntax) I think VCV and PD have taught me a lot about signal processing just by messing around.
To some extent, I think a DSP course that had the student develop modules for VCV would actually be quite successful at meeting these goals.
EDIT: I like being the change I want to see and putting action behind my words, so I think as my DSP, Comm Systems, and Linear Control Systems classes pick up I’ll do what I can to get notes from them transcribed into my website. I already have the barest start of a signals & systems chapter at Sigandsys | Opinionated Guides and some DSP resources linked in Other Resources, Music | Opinionated Guides but both are a mess. @Squinky.Labs I’ll probably link in that page you published about efficient DSP, but if you want to contribute to any of these pages directly that’d be awesome!
Back to the topic though, listening to any demos of these drums I can find, and they quite definitely have a character all their own. I tried to convince myself I don’t need it last night by making a track using some nice acoustic drum samples instead of the Hora drums that end up in basically all the VCV stuff I normally do, but I think all I did was convince myself I need it even more. My Digitakt is going to be jealous 
For my part, I’m definitely not! I guess all I’m pointing to is what I perceive as a lack of resources around current-generation hardware modeling (not that HW is the be-all and end-all anyway, I love pure digital wizardry as much as anyone). @modlfo seems to have a really interesting approach dialed in, with some strong technical foundation and a lot of praxis, and I’d love to see more about it in a studyable form.
Totally agree. The thinness of the wrapper around the DSP kernel (and the scantness of the ceremony) for Rack plugins is a really phenomenal feature of the platform. Speaking of JOS, there’s nothing in Music 320C that would stop a student from using Faust => VCV. I wonder if @jatinchowdhury18 has any insight into how Rack development is appearing at CCRMA or in other grad programs; @vega, does it show up at your uni at all?
You all are REALLY off topic now 
who is Faust and what have he done to Jos?
Thanks for the VCV Drums, imho there are still not enough drums in the library, that’s why I expanded my sample library in the past.
Now we’ve got the drum machine you would have made in the 80s, can you think about the drum machine you would make in the 2020’s please?
@Vega @gc3 I have some resources available that you can check, see the links below. In those I show, with simple examples part of my approach.
I use Wolfram System Modeler, which is the simulator I develop. It is general simulation environment where you can create your own models.
As I mentioned before, variability of the components, in some circuits can have a large impact on a real circuit, and when comparing to a “perfect” simulated circuit the results may differ. I usually follow the inverse approach, which is creating the models in order to reproduce the observed behavior. In my latest blog post in vult-dsp.com (see the links) I mention a case where the hardware oscillators behave different from each other, and different from the simulation. By understanding the behavior I could extend my model to match the results.
I have thought about it but I really don’t have the time. As @Squinky mentions, there are a lot of things that the beginner would need to know beforehand. In addition to the traditional requirements for DSP, it’s necessary to have a good background on electronics. For that reason, in the resources that I have published, I try to make them easy to understand and I don’t really go deep into the most complicated parts.
Lastly…
I have already started making it, piece by piece. Among my modules you can find Knock and Trummor 2. I’m creating more drum modules, but I’m not sure when I will have them ready for release.
WOW! Hat-tip and major respect Leonardo!
Faust is supported in VCV Prototype and using the faust2vcvrack tool. See also 2020-11-21 Faust & VCV Rack - Faust Documentation