Making stand alone modular instruments


Re: website, won’t argue about that either!

Re: 256e, thanks for clarification, my experience with buchla systems is rather limited.


In the context of the present discussion, someone was being told that they should get some VCAs in place of LPGs so @mateo is reinforcing my point rather than contradicting me.

As noted above, a 292e in “gate” mode (or the Euro equivalents I’ve owned) is still not much like a VCA as commonly understood by east coast types: it won’t do AM properly (or at all), it has a weird decay, etc.


welp, we’re kinda saying the same thing. don didn’t make VCAs as components in an AM synthesis chain, he made “dynamic processors” that are intended to be used for dynamics.

for AM synth / ringmod / “frequency shifting” he made a dedicated module.

for the thread topic i think this is kinda relevant for thinking about functional density - 200 modules kinda guide you in the direction of using 2-4 of them for a pretty specific purpose (or thats my opinion.)

quibble; i think a euro module that was “like a 292e in gate mode” would logically be, very close to an opamp based VCA, maybe quite fast, depending on the meaning of “like.” (292e gate mode doesn’t use a vactrol iirc.)


my reading is that you guys are in violent agreement


I am not 100% sure about the 292e, but the 292 definitely used two vactrols in series (tapped in the middle, see one of the many schematics floating around) as the control element in all modes. I think the 292e only adds digital control of the mode switches and control pots, but perhaps someone else can confirm.


It has been a lot of years since I built a 292e, but again iirc I believe we used a quad opamp for the gate path in at least the 2nd and later revs, both due to dwindling vactrol stock and indeed for a faster response

You are correct about the old 292, of course.

I’ll have a peek at a later pcb tomorrow.


so yeah, can confirm that in 292e rev 2 and rev 3, there is no vactrol in the gate path - just LTC202 switch and LF353 opamp.

friendly reminder that these are things i helped build with my dad before he lost his company and died. it’s not entertaining to debate the contents of that BOM.

i thought the pedantry here was lighthearted but then it seemed not so much. kind of bummed out now.


here’s my latest and i control it all from a grids via the ansible
i am very happy with drumbo~


How are you liking Kitty Eyes?


Just a short one on the Natural Gate discussion earlier: If the usage of unorthodox methods for modulation (or no modulation at all) is ones musical vision, that’s a great thing and to me exactly on topic — building a unique ‘instrument’. If everyone was supposed to build a system by the book, we wouldn’t need that thread … :slight_smile:
That said, I would be really curious to have sound examples to each posted instrument in order to contextualise.


It was lighthearted/academic for me, and highly relevant since I’ve never used anything but lowpass gates in my modular rigs–which is (per comments above) not in keeping with the usual way people build Eurorack rigs. I think it helps to show different approaches are possible.

I had never clicked on your avatar until now–or I would never have written something as ridiculous as “see one of the many schematics floating around”. I’m all too aware of the history and sorry this took a wrong turn.


well, no harm no foul :slight_smile:
sorry to be touchy about it.
but anyways i do mostly know what is actually going on in 200e designs in particular; i forget things mostly because of time (292e initial design was over 18 years ago, which makes me feel ridiculously old.)

anyways i’ll keep going for a bit on this topic b/c the module is kind of an interesting case study.
292 (original) has 4 cv “level” inputs, 4 audio inputs, 4 audio outputs, and mode switches, and as you say all amp controls are vactrol.

in addition to the changes mentioned (digital layer under the pots, opamp control of gate-mode paths), the 292e adds:

  • 4 additional cv inputs for “velocity” on each channel. basically when a “velocity” input is patched, it acts as a multiplier for the level input. this opens up a lot of utility for the module as an automated mixer, for example. (you can adjust the levels “post automation.”) this logic is done in firmware.
  • level and velocity can be controlled independently in realtime via i2c without patch cables. (as can gate/lpg mode by means of “preset” recall.)

these are neat ideas and really make the thing more useful as 1/2 or 1/4 of a “standalone instrument,” esp. with the line levels not requiring additional amp/att to interface with outside signals.

now - the 200e stuff was spec’d out in the late 90’s. it has severe technical troubles; AD/DA rates make the CV inputs useless for fast modulation. there is noticeable stepping in some cases, there is clock bleed on audio paths. the current brand owners have no interest in evolving the designs and want to crank out clones and softsynth licenses. so for me, it’s time to see these modules as purely one source of design ideas. one of my favorite things about don’s process was his willingness to radically evolve those designs and some of the clever touches he made to deepen their use cases.


I’ve said so elsewhere in this thread, I’ve had a recent clear out and focused on a 4u 104hp system however I kept a “spare” 84hp case and some modules for this system which I plan to play the op 1 through. Really looking forward to finding time to make it work!

I’m planning to have different settings of IFM craziness on each pressure points step, and some other hands on modulation to compliment what’s being fed in. I think it’ll take a bit of work to get just so…


Just trimmed a bit down from 7u 84 hp to 3u 104 hp with a wooden shelf for grid, norns, and axoloti.


Interesting to see your Please Exist a few modules in from the end. What prompted that?


Rather than on the end? I wanted w/ and the 301 on the end because I want to be able to freely interact with them. It’s not traditional to have a power cord, headphone cord, or in/out in the center of a system, but I’d rather have less hands on modules in the middle.


I go back and forth on that myself, when I shuffle my 6u 84hp, my output often moves from one side to the other or to the center of the bottom row. tactile control surfaces at far left and far right when that happens.


I am considering building this using a old HEK. I wanted to use as the main focus the 2 random*source modules.
All the others are some modules that aren’t being used at the moment.
I plan on using it for drones.
I believe this has it covered for audio sources as well as modulation and mixing, although not that many options.

Besides the other modules in the screenshot, I also have:

  • MTM Radio music
  • MI peaks
  • MN Function (between this and the doepfer LFO, I preferred the doepfer because of the sine wave)
  • MN Optomix
  • Ladik 3ch mixer (not here, because the doepfer one is more silent)
  • Ladik waveform animator (sweet but 12cm deep)

I also have a beatstep pro for gates and cv.
Any suggestions on how to make a nice standalone instrument (without touching the bank)?


I had this idea today while I was walking to therapy.

It would be a while till I could try this myself, so I decided to share this here.

Ansible > Just Type > 2x Three Sisters > Nearness > 2x Chronoblobs (treated as a stereo pair) > Overseer > Rosie

The idea being that as you ping notes, they’ll pop across the stereo field and across the filter ranges of the pair of Three Sisters. Sloths for ample modulation. A pair of Chronoblobs adding some awesome delay possibilities. Overseer for some stereo field madness that can also act as a filter in the Chronoblobs feedback line. Rosie because I like it.

There are obviously other interesting patches one could swing here, but as described, I think it would make an incredibly interesting instrument.

I’d like to try this one day.


Playing around on a VCS3 last weekend rekindled some enthusiasm for Euro, and helped me work out what I want to do with my modular. That in mind, I’ve sketched a couple of ideas on MG, one using the VCS3 as a starting point, and the other based around some Serge Eurorack. Restrictions are the name of the game here! Open to thoughts/suggestions as always.