This makes me so pumped. it sounds great just as great as your other filter models. I hope to hear some more come from you as you do make some(if not the best) filters in the game.
A-150-4 use the AS3360+SSI2144 (image from thomann.de)
http://www.alfarzpp.lv/eng/sc/AS3360.pdf https://www.soundsemiconductor.com/downloads/ssi2144datasheet.pdf https://www.st.com/resource/en/datasheet/tl072.pdf
1 Like
see couple of comments above:
As long as the chips are still made, and I have access to a complete schematic for the internals of the chips (edit: a datasheet is not a complete schematic of the internals of the chip) so I can model any un-ideal behaviour, then itâs a possibility. A lot of these chips donât have public schematics for them, which makes doing a model guesswork, lengthy, and so very costly. Weâre trying to make good value modules, which unfortunately means this sort of protracted reverse engineering isnât possible.
If the chip doesnât do much âodd stuffâ then it can be behaviourally macro modelled with near ideal components - ie I would just model what the chip is producing as an end result without going into many details of the chip itself, which is most likely the situation if anyone has claimed to have modelled these chips. So that may be enough in this situation, but until I have a device in front of me to analyse itâs impossible to tell.
Additionally, some of these chips are revered because of how accurately they stay in tune over a wide range of frequencies, which you actually get for free with a digital model - itâs modelling un-ideal behaviour that takes work!
5 Likes
Yes. The Wasp filter uses CMOS inverters, and that is what Vult modeled for Ferox according to Vult Modules for VCV Rack though Vultâs is considerably more feature full (Notch out, individual enumerators, added post distortion). Without having both I obviously canât speak to CPU usage or sound comparison - though I do have Vult Premium and a Behringer Wasp and testing those against each other the Behringer Wasp has a bit more of a fat, analog sound, which is definitely better to my ears - albeit not by much. Iâm also testing the Behringer Wasp with itâs inbuilt analog oscillator (only 1, set to square) which the best replacement I can best replicate with Vultâs Bleak - so, the difference may be more in the oscillator than the filter, as the waveforms arenât perfect matches, and thereâs probably some plesent analog drift and filtering from the ADC of my interface will likely be more plesent than even the very small amount of aliasing on Ferox⌠which is long winded way of saying, not an apples to apples comparison, but Ferox does sound like a Wasp pretty damn well and Iâd be very interested in testing this A-124 against it, though I canât justify the cost as I do already have Vultâs and the hardware (albeit BehringerâŚ) versions.
EDIT: Just watched the demo video. Those waveforms are wicked close! Regardless of if I get this or not, massive props to the effort put in by @andy-cytomic and the vision of Andrew to bring the A-124 to VCV. Thatâs some next level DSP work, and you bet Iâll be reading all the technical papers on the Cytomic website in the hopes that I can absorb even a bit of your black magic powers!
3 Likes
Iâd love to cast my vote for the A111-X and A106-6
thatâs cool, but Vult has been doing amazing analysis and emulation for years, and has (I think) given papers about that at Mathmatica conferences. So, to me, that was already ânext levelâ. Itâs not super clear what is next-next-level bout this wasp clone vs Vultâs much earlier Wasp clone. But thereâs always room for more nice filters, so thatâs good.
2 Likes
ooh - that SSM-2044 was always one of my favorite filter chips âback in the dayâ. Thatâs why we put 8 of them in the Voyetra-8. They sounded so good!
For me itâd be the A-110-4 (Trapazoidal, Through-0) A-199 (Spring Verb) A-188-2 (Tapped BBD)
Yes. I modeled Ferox after my own DIY Wasp based on the J. Haible schematic. As with all my models, the fact that I do not port existing modules gives me the freedom or adding my own tweaks. So never expect to have a perfect match of one of my models with existing modules.
Some weeks ago I had a short conversation with @andy-cytomic and he found a bug in Ferox. I accidentally limited too much the top cutoff frequency. While fixing this, I took the time to make a few improvements and the upcoming 2.0.5 version of Vult will have an improved Ferox.
23 Likes
No, Iâm doing an ultra detailed model of the Doepfer A-124, the Vult Ferox is not modelling this hardware at all from what I can tell since they sound so very different (edit: Leonardo has said he based his on the J. Haible schematic, which I can confirm is not the same as the Doepfer schematic). The A-124 Wasp filter module, and other analog Wasp filters Iâve heard, do a âwarbleâ kind of sound where you have the resonance up around 9 or so, then drive the input up to around 8-9 as well and you get this wonderful unstable sound, I cannot hear this type of thing at all in Ferox not matter what I try.
4 Likes
Thanks for doing an update to Ferox, itâs a unique sounding filter, and has loads of drive, so I look forward to having a go with it if the filter cutoff can get higher than the 6.3 kHz of the old version.
2 Likes
This is fantastic news for VCV, and for music in general! I canât wait until I have the time to try this out properly.
Congratulations are due all around.
@andy-cytomic, your VST plugins are top-class and from the demo video this is just jaw-droppingly good as well. I actually have this in HW and you seem to have captured its very distinctive voice and in-between instability. Canât wait to see what comes next!
(If youâre taking requests, any chance of the A-106-1? That thing is an instrument unto itself. Obv. the res insert will work a little differently w/the cable sample delay, but I think it would still be very interesting even if it could never match the HW exactly. Also, bonus points for switchable noise/bleed if you donât deadpatch HP In 
)
I know what you mean with the âwarbleâ. Thatâs something that I decided to remove in order to simplify my model and also because I did not like that sound much. Interestingly, my Jasper (Wasp), which I built last year, does not produce that âwarbleâ neither.
1 Like
Other important thing to notice is that the CMOS inverters used as op-amps have a lot of variability. I remember when I was doing my prototype that I had a bunch of CMOS inverter ICs, some old from my early electronics days and new from different manufacturers. Just by swapping them on my prototype I would get different behavior. I picked the ones that sounded better for me and used those to fit the model of the inverter.
I would assume that manufacturers like Doepfer always use the same part number in order to reduce this variability and provide a more consistent sounding module.
3 Likes
Without wanting to minimize other developer contributions, let me state the obvious: @modlfo makes modules that Just Work, & sound great.
I keep trying modules that look good, but donât work as I think they should. I try to log the issues on GitHub, but sometimes I just drop on a Vult module & keep working.
I donât have that âAdd module, get weird results, replace moduleâ cycle with Vult, ever
7 Likes
I agree with you. I think @modlfo writes excellent modules, and I use them myself and like them a lot, that is not being questioned here at all. Itâs great to have a variety of high quality choices of modules in Rack, and I hope I can increase those options for the community.
The point I disagreed with was the answer to the question âIs (the Doepfer A-124) the same filter that Vult modeled for Ferox a few years back?â - to which the clear answer is No, but Vult answered Yes, so I wanted to clear that up.
2 Likes
That is the second serious request for this device, so itâs definitely a possibility. I was thinking one bread and butter filter like the A-120 and one character filter (the A-124 Wasp), but now I think Iâll have to get both the A-120 and the A106-1 to test them out to make that choice.
2 Likes
I was actually thinking of doing the A-110-6 (Trap Thru Zero Quadrature Osc) - which from what I can tell is an updated A-110-4. I wanted to tackle more standard modular devices like osc / filter / amp for this first collection, but doing a spring reverb or bbd may be good in the future.
3 Likes