VCV Rack // Cytomic - Doepfer module suggestions

[foosnark]

I've owned a few Doepfer modules but a lot of it tended to be basic utility stuff that is pretty well covered in VCV already (like the A-138m matrix mixer), or else something that I found I preferred elsewhere (e.g. the A-101-2 LPG is OK but it can't compete with a Natural Gate...)

The standout ones for me though are the A-188-1 BBD, and the A-196 PLL.

Softube has a version of the A-188-1 but from the demos I've heard, it seems pretty unconvincing. They modeled the clock whine but it just doesn't have the same drive and dirt, it sounds more like the aliasing from a simple sample and hold patch.

In Eurorack I tend to patch PLL stuff myself using various things as a phase comparator -- even just a VCA can work in some cases -- but I've never had any success patching PLLs in software. A decent A-196 module for VCV would be very welcome.

[Henry Von Wilheimer]

Stoked to have the first of the Doepfer series land in VCV. I remember Andrew Belt mentioning plans for them in a live stream pre-VCV 2 release without naming the person behind them. I kept thinking hmm it's gotta be the Cytomic Andrew.

Besides the filters, of which i'd probably buy every one of, I'd love to suggest the A-188-2 Tapped BBD. The sound and versatility of that in VCV would be insane. Maybe even tweak it and give the option of keeping or removing the clock noise? I'd probably pick up most of the collection though if many modules came to fruition. Even VCAs and such if they added small splashes of character.

[whyterabbyt]

The A-106-1 does look interesting, do you have one?

yup.

There are no public schematics for the CEM3340 that I know of (I'm talking about the actual circuit diagrams with all components and values of everything inside the IC, not the datasheet!), but if you know of one and can post me a link I'd appreciate it It's difficult to model something accurately without a schematic, otherwise it's just guesswork and rough behavioural modelling (ie just modelling what the IC appears to do from the outside).

sorry, I dont, I had assumed that was 'known stuff' by now, what with the various cloned chips etc. i even had a vague recollection that there were copies of the original litho masks floating about but I cant find any reference to that now.

[andy-cytomic]

The A-106-1 does look interesting, do you have one?

yup.

Great, it makes your feedback stronger since you've got experience with the device. I've had another request on the VCV Rack forum (unless it's you that is gc3 on that forum!?)

sorry, I dont, I had assumed that was 'known stuff' by now, what with the various cloned chips etc. i even had a vague recollection that there were copies of the original litho masks floating about but I cant find any reference to that now.

Perhaps I can just casually email them and ask for the full schematic so I can emulate the device accurately so they won't have to go to the trouble of manufacturing as many of their chips?

[whyterabbyt]

unless it's you that is gc3 on that forum!?)

nope, that's not me.

Perhaps I can just casually email them and ask for the full schematic so I can emulate the device accurately so they won't have to go to the trouble of manufacturing as many of their chips?

Worth a go...

[andy-cytomic]

BTW does the Wasp filter have the self-oscillation mod? (https://doepfer.de/DIY/a100_diy.htm)

As I said before this mod doesn't really work, and I showed the plots of what is going on. But...

I do know how to do a proper mod from previous experience with this sort of circuit and the OSCar SVF and just tested it out on the Wasp and it's sounding great, so I hope to be able to add this to the official VCV Rack module as a right click option. It only requires soldering two resistors onto the circuit, and doesn't change the original timber and function too much. I would still probably put a couple of switches on the hardware to allow for bypassing the mod, since the original sounds great. I'll post some more details in the next couple of days including photos of the v4 Wasp and where to do the mod, and also post this mod to Doepfer so they can list a better option on their mods page. Here is a quick audio demo, starting with it just into self oscillation, then increased to full resonance self osc, then I start pushing up the level control with a sawtooth input to drive the filter.

https://cytomic.com/files/forums/doepfe ... mod-02.mp3

[Funkybot's Evil Twin]

Love that you're creating hardware mods than kind of backporting to the software (or vice versa)! I'd personally just love to see straight ports of some "The Drop" filter circuits to VCV Rack too - outside of Doepfer. Any chance of that? Maybe a bundle of modules, or a single module with different filter types and some CV inputs (Vult has the Freak with a generic interface and ability to select filter models/type).

[Shabdahbriah]

BTW does the Wasp filter have the self-oscillation mod? (https://doepfer.de/DIY/a100_diy.htm)

As I said before this mod doesn't really work, and I showed the plots of what is going on. But...

I do know how to do a proper mod from previous experience with this sort of circuit and the OSCar SVF and just tested it out on the Wasp and it's sounding great, so I hope to be able to add this to the official VCV Rack module as a right click option. It only requires soldering two resistors onto the circuit, and doesn't change the original timber and function too much. I would still probably put a couple of switches on the hardware to allow for bypassing the mod, since the original sounds great. I'll post some more details in the next couple of days including photos of the v4 Wasp and where to do the mod, and also post this mod to Doepfer so they can list a better option on their mods page. Here is a quick audio demo, starting with it just into self oscillation, then increased to full resonance self osc, then I start pushing up the level control with a sawtooth input to drive the filter.

https://cytomic.com/files/forums/doepfe ... mod-02.mp3

Awesome! That sounds worth getting another (hardware) Wasp for.

[whyterabbyt]

Awesome! That sounds worth getting another (hardware) Wasp for.

indeed!

[kobal]

A-105 24dB SSM Low Pass Filter would be nice
A101-1 Vactrol

i guess most of their filters would be nice to have in vcv actually

CEM3340 version of the A-111 VCO

most intresting to add to vcv would be definlety vcos and filters to me .

many of the vco i use in vcv tend to sound very similar to each others and not really as good as analog ones it seems even if i haven t compared side by side.

personally i find some doepfer vco and filter can have really nice caractere, i don t know their others modules, i have a friend with loads of module and he still love some doepfer vco and filters

[Chibs]

This is very exciting, the wasp really sounds like I'm used to! My (slightly too big) system is about 50% doepfer, so very curious to see what's to come.

Regarding module suggestions, there's a few I consider core to most of my physical patching, I do most of my sequencing with doepfer modules. These might also not be as challenging to design for VCV, but add a lot to what makes doepfer, doepfer, for me. These are:

A-152 Voltage Addressed Switch
A-151 Quad Sequential Switch
A-160-2 Clock Divider
A-138m Matrix Mixer

The A-154 and its controller are also worthy of attention for sequencing. Of course other modules exist out there in VCV that handle such things, but few are as well designed as the Doepfer modules.
On the sound generation / alteration front plenty is already said, the A-110-2 and A-110-4 are excellent choices for oscillators. and few doepfer filters disappoint, A-121 is one of my favourites. The A-196 PLL would also be a blast, and as a plus seems like it'd be a lot of fun to program.

Best of luck and curious to what you come up with!

[kobal]

there are replacements to the some of these modules in vcv so i m not sure it s worth to make something that overlap with free modules , or the one vcv sells already.

[Owen_E]

The two osc I thought would be best from reading the specs are:

* A-110-2 Basic VCO
* A-110-6 Trapezoid Thru Zero Quadrature VCO

These are the two I would have suggested (tho they're also the only two I have in hardware). For me, simplish and carefully modelled analogue oscillators feel like a missing building block in VCV.

[Funkybot's Evil Twin]

The two osc I thought would be best from reading the specs are:

* A-110-2 Basic VCO
* A-110-6 Trapezoid Thru Zero Quadrature VCO

These are the two I would have suggested (tho they're also the only two I have in hardware). For me, simplish and carefully modelled analogue oscillators feel like a missing building block in VCV.

What's the expectation for analog osc when it comes to polyphony? Do you expect some drift and tuning offsets? What about timing offsets on envelopes? Slight cutoff and resonance offsets on filters? I say yes! But then how about other control signals and processors (LFO's, mixers, mults, switches)? Probably less desirable there.

Just stuff that I'd think any developer would need to keep in mind when it comes to VCV development. Polyphony isn't something that needs to come into play on hardware, but since VCV allows for it, I kind of think these offsets should be built in where they make sense.

[Henry Von Wilheimer]

The two osc I thought would be best from reading the specs are:

* A-110-2 Basic VCO
* A-110-6 Trapezoid Thru Zero Quadrature VCO

These are the two I would have suggested (tho they're also the only two I have in hardware). For me, simplish and carefully modelled analogue oscillators feel like a missing building block in VCV.

What's the expectation for analog osc when it comes to polyphony? Do you expect some drift and tuning offsets? What about timing offsets on envelopes? Slight cutoff and resonance offsets on filters? I say yes! But then how about other control signals and processors (LFO's, mixers, mults, switches)? Probably less desirable there.

Just stuff that I'd think any developer would need to keep in mind when it comes to VCV development. Polyphony isn't something that needs to come into play on hardware, but since VCV allows for it, I kind of think these offsets should be built in where they make sense.

I'm thinking it's better to not have those offsets built into modules unless there is an option to switch them on or off. Although I consider them very desirable and have been thinking about how to most efficiently implement them in VCV (Learning from the thread on VCV that's describing this), I would want to make my own custom static offsets if you will, and cycle through them. If these offsets are baked into the modules with no option to turn them off then i have to calculate against whatever the developer did, surely making it far more complicated to implement my custom deviation.

So let's say I want to play an arp with 6 voice unison. I would make one voice the "extreme low" for various envelope timings and another the "extreme high", with the 4 voices in between changing their static positions relative to those constants with a "minimum variation" that I decided on. Cycling through 4 different groups of 6 voices for example, each group only sharing the extreme high and low.

And Similar idea for VCA and filter cutoff/resonance/drive etc. For an amplifier a minimum loudness voice and a maximum loudness voice. Of course you don't have to do that and can just have all 6 voices vary from each other in all 4 groups, not accounting for a minimum or maximum. It may even be better to have separate group timings for different patches. When you have a long attack time you have to be careful with offsets that are timed too far apart. They can start to sound way out of sync. With shorter attack time patches they might sound great.