The knob named "rate" is the one some might call "range" in secret. What documentation there is saya that it goes from approximately 3kHz down to 5 minute orbits. Ian Fritz told me that negative CV will slow it down even further. Perhaps it can be driven even faster too, but I didn't ask... Really cool circuit anyway :)


Are there any chaos modules that have the ability to go from LFO rates to audio rates "smoothly"?
-- prester_john

Check out the Ian Fritz Hypster from Nonlinearcircuits: https://www.modulargrid.net/e/nonlinearcircuits-ian-fritz-s-hypster


I see you've got a couple switches in there already. Do you blow your hair back the way they do mine?
-- wrecksmoondee

What would you say is your most recent "favorite" use for your switches?
-- merzky_shoom

I guess I love them for "generative" surprises. I love how I can load them like a revolver with different sound bullets and have them fire off and do their thing. Sometimes I'll have a suitably primed filter doing double-duty: taking (A) a percussive element and (B) a "tonal" element. So the switch will be loaded with (A) a trigger and, say, (B) a mixed pair of VCOs making a simple chord; these will alternatively be sent into the filter. If I have another switch handy, the CV-in of the filter can take alternatively an envelope and a random voltange or an LFO and an audio-rate VCO. The basic idea is alternating elements. I suppose one might use a crossfader in a similar way. In any case, I've found switches to be the utility that leads to me sitting back and listening to this strange instrument with a big grin on my face.

*EDIT: I should add that what counts as "enjoyable" and "musical" for me, and thus what makes me grin, is perhaps quite idiosyncratic, so, as they say, "YMMV".


I'd want a lot more utilities
-- JimHowell1970

WRT this point, any kinds of utilities you see missing from this that you personally couldn't live without?

-- merzky_shoom

Sorry for eavesdropping. The utilities that I've especially fallen in love with are switches; the Doepfer A-150 and A-151 in particular. I'm always thinking "boy, what I could do with one or two more of these." So I'm planning on getting another one or two more.

I see you've got a couple switches in there already. Do you blow your hair back the way they do mine?


I guess a lot hinges on what "complex" means, but the Doepfer A-154/A-155 sequencer combo is certainly well-featured.


Man oh man, a fellow can dream. I couldn't justify the expense for a hobby, but it's fun to imagine.


I think each of us has a different definition for "functionality," so your approach to a unique, personalized instrument is vastly different than mine, which is great. Yes, this will likely do the things you want unless your idea of experimental evolving textures includes sounds that you would find in something like the Spherical Wavetable Navigator, Panharmonium, Rings, or other wacky digital modules. I like some stuff like that, so your plan wouldn't be quite as functional for me. -- farkas

That's a good point; some of this stuff is subjective but here I am looking for an objective answer to a question phrased in objective terms. I guess fundamentally I'm checking whether there's some obvious blind spot in my plan--as is often the case in these kinds of posts from what I've seen--but I've been fairly reassured.

Either way, it seems like you have a good understanding of synthesis. Dive in. Buy some modules. You'll know if your plan is a good one once you start patching. Have fun with it!

-- farkas

Cheers farkas, thanks for your time. I hope you have fun too.


Considerable changes...here we go... ...and it's still 100% Doepfer! Whatcha think? -- Lugia

Considerable changes is a considerable understatement; it's a radically different instrument! Before I go in to why it won't be my instrument, I want to thank you for taking the time to complete this exercise--it's like crosswords or sudoku, isn't it?--as it's helpful for bouncing ideas around.

I'm gonna bang on this a bit and see if I can up the functionality in some other ways as well...even while staying 100% Dieter here. -- Lugia

So, having studied your model briefly, my impression (and this could be founded on my own inexperience) is that more has been sacrificed than has been gained.

In opting for a "larger system" (15U is nothing to sneeze at, I think) I don't think I should have to sacrifice ergonomics to the slimline series, so I've deliberately avoided those. They were designed, according to Dieter, for situations such as the little beauty cases that people like to put together. I'm happy for a few fewer, but easier to "handle" modules. And, again, I don't think much (if any) functionality is lost in my case.

Some of the more interesting VCOs that I think would have offered a more interesting timbral palette (especially the A-110-4 Thru Zero VCOs) have been lost; this deviates from the basic aim of the build, namely interesting timbral variety.

The only thing that I can see that's got an exponential response is the A-138 in the lower cab. -- Lugia

I intend to use this as the final output, plugging either a pair of headphones into here or using a longer cable with a 1/4" adaptor to go into my external passive mixer (Art SPLITMix4) which connects to the home stereo system. From what I've read online, it's common to use the A-138 as the final output. Also common, from what I've read, is people using linear VCAs almost exclusively, even for audio, contrary to the received wisdom in lin=cv, exp=audio. So I think I'm going to try my luck with linear VCAs and adapt if the need becomes obvious.

Added an external input/envelope follower for processing external sources. -- Lugia

This, instead of the FX insert that I plan to use to bring a few interesting pedals into the signal path. You mentioned you were torn about the this module, but I'm keen the keep it along with the reverb and bit crusher, which latter ought to prove interesting for cv too.

And the 2/3/4-position VC Switch is down at the end of the sequencer, where it needs to be to shift from dual 8 to single 16 CV row behavior. -- Lugia

My impression is that the A-150 Dual VCS is sufficient for shifting from dual 8 to single 16 CV row behavior on the sequencer. Is that not the case? That would free up the s/3/4-position A-151 Sequential Switch for more interesting applications.

Plus, by swapping the sequencing modules to the "flat" row, you now have the system's primary controller where it belongs. -- Lugia

I've read that the sequencer or controller may not fit comfortably in the "flat" row due to the power supply; I had originally intended to place it there until I read that. It's not a dealbreaker for me at all.

So, I want to thank you again for engaging in this exercise with me. Given my resistance to your radical revisions, I imagine it might feel like thankless work, so I want to make sure I have enough gratitude buffer in here.

I want to conclude by reiterating this general question: given the stated aim (the ability to generate a broad palette of interesting "experiemental" and evolving timbres and textures; generative patches; loads of modulation; loads of flexibilty; both control and room for the unexpected; a unique, personalized instrument), am I actually falling short functionality-wise in the sense of failing to realize the aim? I grant that the aim could be achieved differently and with smaller modules, but that's another matter.

Cheers Lugia!


My concerns here are that there's too much attention being devoted to aesthetics and not enough to functionality.
-- Lugia

Thanks for your feedback, Lugia. I hear you, and I reckon that I could cram more in a smaller space by mixing and matching. But given what I've presented here and the stated aim, am I actually falling short functionality wise in the sense of failing to realize the aim?

To fill in the background a bit, I can confirm that I will be the only audience; this is a hobby instrument for my own pleasure, so aesthetics has its place; and I think the risk of an endless search for novelty/increased functionality is a real one--folks confess/lament it frequently, so I think a strategic buffer against that (by aiming to stick to Doepfer) might be wise.

Note, though, that you can get away with only linear VCAs in a build as long as you have exponential EGs to make them conform to the exponential loudness curve. -- Lugia

Any insight into whether these Doepfer EGs are exponential?


I'm not sure if my old ears could tell the difference, but it may be nice to have the option.
-- farkas

I think that the VCA portion of the A-101-2 Low Pass Gate is exponential, so that ought to at least give me a sense of the flavour and provide the option if needed. Thanks for pointing me towards more info!


Sounds like you have a great plan, and I'm sure this system will give you many years of excellent service!
-- farkas

Cheers mate. As you pointed out, there are no exponential VCAs here; I'm hoping to get by with just linear. Based on your experience, is that feasible?


Hi wrecksmoondee. Looks like you have just about everything you'll need.
You are off to a great start here, though I wouldn't recommend buying everything at once. If you just buy a few modules at a time, that will give you the opportunity to adjust your plans on the fly to incorporate modules that may be a better fit for the type of music you want to do.
Have fun and good luck!
-- farkas

Hi farkas, thanks a bunch for your feedback.

Maybe some exponential VCAs (unless I overlooked those) and additional attenuverters, though the matrix mixer may work for inverting signals. > -- farkas

It's true, no exponential VCAs here; I'm hoping to get by with just linear, I guess. Is that feasible? If not, what should be dropped instead? There are a few polarazers there and I also have a couple some passive attenuators (basically little external patchable volume knobs) that I hope will do the trick for inverting and/or attenuating signals.

Will you be adding any external effects? -- farkas

I have a few quirky pedals that I plan to bring into the signal path: Chase Bliss MOOD, Pladask Fabrikat, Red Panda Tensor and Particle.

Also curious if you are only interested in Doepfer, or will you be researching other manufacturers too? As much as I really want that A154/A155 combo, but there are very capable sequencers in a much smaller footprint. -- farkas

Currently, I'm planning to stick with Doepfer; this for reasons both strategic and aesthetic. Strategically, I hope that sticking with Doepfer will be a buffer against getting lost in a constant search for novel modules--there's just so much out there and I would always wonder if the next thing is better for me. And I bet there's a lot to discover right here. Strategically, too, I think working with Doepfer's building blocks will provide a deep education in modular synthesis and "patch programming". Aesthetically, the look and consistency appeal to me. I reckon it's like how some folks dig going for all Serge or all Buchla or whatever.

Thanks again for your feedback!


Hi everyone,

Been searching high and low for tutorials on using the Doepfer A-171-2 VCS Slew Processor/Generator Serge clone module that came with my Doepfer A100 Basic modular system but cannot find anything on how to patch it and the manual is less than useless from Doepfer.
-- sacguy71

Hi sacguy71,

Have you gotten a handle on this module yet? Did you find any useful tutorials? How do you find yourself using it?


Hi folks,
I hope some seasoned modular moguls can take a look at the system I'm designing and offer feedback. It's 15U spread across two cases (a Doepfer low cost case (9U) and low cost base (6U)) as seen in the following: (Edit: the bottom case doesn't seem to be displaying in it's most up-to-date layout; clicking the link should display the updated version)

ModularGrid Rack
ModularGrid Rack

The aim guiding the design involves: the ability to generate a broad palette of interesting "experiemental" and evolving timbres and textures; generative patches; loads of modulation; loads of flexibilty; both control and room for the unexpected; a unique, personalized instrument.

Do you reckon this 2-part system can satisfy the stated aim? Any obvious omissions or redundancies? Something I might have overlooked?

Thanks for your time,
wrecksmoondee