Cytomic "The Drop" Resonant Filter

[kritikon]

Now how on earth did I manage to miss this thread? I obviously don't visit Effects often enough. Must admit I don't often buy s/w nowadays - it has to be something a bit special to get my wallet out...those transistor SKF sweeps ooze character. It's why I still treasure some of my old analogues - and way too many s/w filters are just flat and lifeless. Not these though. Jeez, if the missus wasn't sleeping after night shifts I'd be straight over to the studio to switch on the MS20 and get it screaming, as those clips got the juices flowing. I can think of some serious damage this filter can do to some boring old digital audio.

Nice work Andy. I think I'll be a customer.

[andy-cytomic]

I'm now aiming for mid March

How about a (little discounted) unofficial preliminary version (as it is now) for the enthusiasts?
You could start selling it right away!

I'll start selling it as soon as possible, but at the moment there isn't even a gui, just a big long row of faders that even I find hard to navigate and I wrote it!

[andy-cytomic]

Hahahahahaha has dragged on a little now hasn't it hahahaha
Maybe a rethink on announcements next time lol

I did take on too much work doing the AAX version of The Glue, as well as something else I'll be able to talk about late Q2. So sorry to be holding out like this on everyone, but I am working flat out to get it done.

[andy-cytomic]

Listening to the demo's this is the most analogue sounding filter I have ever heard from a digital source.

If you make a synth with all the same principles... I will be unhappy, as I don't think there truly will be a difference anymore between analog and digital and it will be so hard to tell the difference we will all feel deflated about paying so much for an analog synth.. hehe

You realize Andy wrote most of DCAM: Synth Squad, right? It's already hard to tell the difference between those instruments and an analog.

I think there is always going to be a slight difference between analog kit and digital models, but The Drop will be closing the gap even further. I love good analog kit (although there is plenty of bad analog stuff around as well, just because it's analog doesn't make it automatically good). It doesn't have to break the bankEither a Moog MF-101 filter pedal, or a small synth like a Doepfer Dark Energy, or a Korg Monotron, or some other second hand pedal or synth, you will not regret it! I hope there will always be a place for analog kit, but plugins are useful as well so they really complement each other.

[andy-cytomic]

Now how on earth did I manage to miss this thread? I obviously don't visit Effects often enough. Must admit I don't often buy s/w nowadays - it has to be something a bit special to get my wallet out...those transistor SKF sweeps ooze character. It's why I still treasure some of my old analogues - and way too many s/w filters are just flat and lifeless. Not these though. Jeez, if the missus wasn't sleeping after night shifts I'd be straight over to the studio to switch on the MS20 and get it screaming, as those clips got the juices flowing. I can think of some serious damage this filter can do to some boring old digital audio.

Nice work Andy. I think I'll be a customer.

Hey kritikon. Thanks for great post, especially from someone that has an MS20 (as well as other analog synths) and knows what to look out for in terms of tone, very much appreciated!

The transistor skf is the most advanced circuit model I've done to date, it is very non-linear, and very hard to model right, and I've got exactly the same problems as the real circuit does in terms of dc blocking and tuning. I have to work out some way to "warm up" the circuit so it doesn't take half a second to "switch on", and I have to work out how to get it to tune more accurately because of the inherent self fm that always goes on throwing things out.

I wasn't even sure I would be able to include it since there is so much doing on to model it took loads of cpu, but I have managed to come up with some very good optimisations, so now it only takes lots of cpu instead of ridiculous amounts of cpu

[highkoo]

This thread is going to end up being on the front page for two years.

[sonicpowa]

-- at the moment there isn't even a gui, just a big long row of faders that even I find hard to navigate and I wrote it!

Well I'll take it! It's even more interesting like that..
The coding probably is a bit incompatible with the final version though.

[kritikon]

The transistor skf is the most advanced circuit model I've done to date, it is very non-linear

And it shows. I think this is what many of the young'uns used to s/w haven't heard with analogues. I read many threads where obviously young posters rant on about how s/w is every bit as good as old analogues, and there are so many holes in their arguments. Good s/w surely is as good as some of the better analogues. Bad analogues are just as lifeless as many VST instruments. Even some of the better s/w filters can have some character but still sound lifeless. I shouldn't name names, but as far as character goes, Fabfilter sell one of the best synths and filter in terms of character. It has that nice overdriven warm sound when you push it, but it simply doesn't move. I know exactly what sound it's going to make every time. The only way you can get movement into the sound is by making other parts of the synth modulate, by adding some chorus, by adding some subtle pitch mod or filter mod with LFOs. Not a bad thing in itself, because their synth has lots and lots of mod options. But on its own the filter, although it has sonic character, doesn't move.

But when you hear Drop Filter you immediately hear the movement in it. When you run a continuous loop round with some characterful analogue like an MS20, or a Yamaha CS40 or above etc, you can loop the sequence around for 5 minutes, and if the filter is overdriven, you'll never hear the exact same phrase twice. Because it's always moving. And this is with a synth that has pretty stable VCOs, so you're really not getting much in the way of pitch mod and chorussing between oscillators. It's the filter that is the really fluid thing. You can hear it in Andy's audio clips - that filter wobbles its way up and croaks and fizzes in different ways all the time.

so now it only takes lots of cpu instead of ridiculous amounts of cpu

I can live with that. It'll finally make me upgrade my old PC, I suppose. For a truly fluid filter, it's worth the extra CPU. And I hope more people accept that to get truly fluid s/w, although it can be optimised, it has to use far more CPU than those lifeless synths that let you use multiple instances because they've compromised sound for efficiency.

I can imagine running some MS20 lines through Drop Filter, and I hate to say it, but GMedia are going to lose their "screams like a bastard" title...

[sonicpowa]

-- now it only takes lots of cpu instead of ridiculous amounts of cpu

But there's going to be realtime/offline choices on the back panel, right?
Maybe Draft, Good, Excellence and for offline: Excellence, Perfection and Obsession like in Aether.
Export with Obsession could take days..

[andy-cytomic]

The transistor skf is the most advanced circuit model I've done to date, it is very non-linear

And it shows.

Thanks! Because of the structure of the filter if the input level is increased the is large modulation of the cutoff in very complex ways, and even the dc-blocking capacitors have to be included in the core of the filter solver because of the audio rate "self modulation" present.

...But when you hear Drop Filter you immediately hear the movement in it. When you run a continuous loop round with some characterful analogue like an MS20, or a Yamaha CS40 or above etc, you can loop the sequence around for 5 minutes, and if the filter is overdriven, you'll never hear the exact same phrase twice. Because it's always moving. And this is with a synth that has pretty stable VCOs, so you're really not getting much in the way of pitch mod and chorussing between oscillators. It's the filter that is the really fluid thing. You can hear it in Andy's audio clips - that filter wobbles its way up and croaks and fizzes in different ways all the time.

Hopefully I'll even improve on the movement front I've got the non-linearities and large signal circuit modelling all in there, but I've still got to add the physically accurate noise modelling. My initial tests in this area have been very encouraging, it is completely unlike just adding noise to the input signal or cutoff, which are tricks people usually use.

[andy-cytomic]

-- now it only takes lots of cpu instead of ridiculous amounts of cpu

But there's going to be realtime/offline choices on the back panel, right?
Maybe Draft, Good, Excellence and for offline: Excellence, Perfection and Obsession like in Aether.
Export with Obsession could take days..

Yes there will be options for realtime and render oversampling amounts, just as there are in The Glue. If I have time I'll also add a non-linear phase option, since this reduces latency if you are using The Drop live. Even without oversampling the filters will work over the entire frequency range.

[andy-cytomic]

I've got a near final parameter set now that I can share with everyone and would love some feedback and discussions on it, especially if it involves being able to remove un-needed / confusing parameters. I have tried to keep the number of controls to a minimum, even though it may not seem like that at first glance of the list!. The gui will be made so that you can easily adjust the high pass and low pass cutoff and resonance, as well as drive and amp without getting bogged down in the modulation and other features.

High Pass into Low Pass dual serial filter
--
LpFreq - low pass cutoff freq
LpRes - low pass resonance
HpFreq - high pass cutoff freq
HpRes - high pass resonance
Circuit - Svf Ota, Skf Ota, Skf Trn, Svf Ota Dst, Skf Ota Dst, Skf Trn Dst
Drive - pre filter gain
ResLimit - keeps resonance below 99%, good for live if you don't want self oscillation
Spacing - stereo offset of cutoff
Linked - like the hp cutoff to the lp cutff, use "step" to control the offset of each filter
LpMod - global mod depth on low pass freq
HpMod - global mod depth on high pass freq
FmDepth - frequency modulation from audio input / sidechain
LpFreqStep - non smoothed low pass cutoff in semitones, good for automation step patterns
HpFreqStep - non smoothed high pass cutoff in semitones, good for automation step patterns
LpKeyTrk - track low cutoff with midi note
HpKeyTrk - track high cutoff with midi note

LFO capable of audio rate modulation
--
LfoDepth - cutoff modulation from lfo
LfoMode - Unipolar, Unipolar * Env, Bipolar, Bipolar * Env
LfoFreq - freq in hz of lfo
LfoScale - linear scaling of lfo freq, can take up to audio rates
LfoBpmSync - sync to bpm
LfoWidth - smooth change from saw up, to triangle, to saw down
LfoExp - exponential curve of lfo edges for envelope / reversed envelope shapes
LfoSwing = alternate cycles get different times but two cycles still take the same time to complete in total
LfoPhase = start phase of lfo
LfoOffset = stereo separation of lfo
LfoRand - random variation of end points of lfo
LfoTrigSource - Auto 1/2/3/4, Audio, Midi, Manual, None
LfoTrig - manual automation control to trigger the lfo, so no midi needed
LfoKeyTrk - track lfo freq with midi note

ADSR Envelope + Envelope Follower
--
EnvDepth - mod depth of cutoff
EnvMode - ADSR = regular adsr, Follower = envelope follower
EnvAtk - attack time (used for follower also)
EnvDec - decay time (used for follower also)
EnvSustain - sustain level
EnvSens - envelope follower sensitivity
EnvRel - release time
EnvTrigSource - LfoLinked, Audio, Midi, Manual
EnvTrig - manual automation control to trigger the env, so no midi needed

Amp
--
Amp - post filter gain
AmpMode - On = always on like an effect, Gate = fast on / off, Release = fast on with release time from ADSR, ADSR = use full adsr settings - uses the same trigger source as the ADSR
Mix - wet mix

Global
--
Power - global on / off button
ExtSidechainIn - switch to enable input 3/4 as the input for fm and envelope follower
LpIn - switch to enable the low pass filter in the signal chain
HpIn - switch to enable the high pass filter in the signal chain
Noise - circuit noise

[sqigls]

Holy sh!t andy, controls to a minimum?
It's pretty feature packed. I could suggest cutting a few things,
but I know i'd find them useful in the long run.
Wow man. So keen to hear this plug. Aaahh the oversampling...

Would you consider an 'LE' version along side of this litlle bad boy?
Or is that defeating the point of it all?
Undersampling?
:p

[sonicpowa]

The list is just about perfect. Can't wait to test it..

[filterdude]

Rrrreally looking forward to The Drop!!

Bert

www.filterheadz.com