ModularGrid Rack

Hi all, I'm putting together a system for both music-making and teaching. We already have a few synths in the department, and I wanted the modular to be a bit different.

The Mother 32 will stay outside the rack, as to allow individual use, and I went with the 104 HP case for future expansion.

My sticking points are whether I need the quad VCA, or a more simple one would suffice (and save some £££)

I would appreciate any advice you have, and perhaps where to go next to fill the rest of the case, ideally with more modulation and effect processors. I would avoid Make Noise in this system, as we eventually plan to get a Shared System (unless you think any of their modules that's worth doubling up?)

Thanks in advance!


i would definitely keep the quad vca - but i'd swap to veils


Thanks for the reply. Do you mean swapping Quad VCA for Veils?


yes it's 2hp smaller - and it keeps you mostly mutable.. for what that is worth

btw - if you can find one grab kinks - it's a really useful little module and it's recently been discontinued


Great, Veils seems a little cheaper too. Wasn't going for an all MI, but hey, might as well!

Thanks for the advice, will also look Kinks up too


Hmmm...well, let's see. As someone who went through the academic music system (until I got to Illinois, which taught me a lot of "interesting lessons" about academic composition...to the point that I quit academia altogether), the idea here to create a "teaching synth" is good...but you have to impose certain limits on the build so that you don't have a lot of confusing gewgaws in there that no one will likely encounter in the real world. As for me, I learned on an ARP 2600, which I STILL say is perhaps the sine qua non of educational synths. Given that I've found that there's little to no significant differences between any of the Rev. 2, 3 or 4 2600s and the Behringer 2600, having one of those around is something I would strongly suggest. You can also mount it in a heavy rack, which discourages it from "going walkies". The Palette 104, on the other hand, is EMINENTLY stealable...it has no Kensington lock port, it's small enough to fit in a backpack or under a coat, and its Meanwell brick is even more stealable; if someone needed a brick for their own rig, there'll be a temptation to snarf that supply. Also, the tile row is still a bit of an "unusual" feature that's still not 100% in common use. So, I banged out something here...
ModularGrid Rack
The idea was to create a teaching synth, a system that's specifically designed to show what the basic functions of subtractive synthesis are and what they do...and also, to show what happens when you start interconnecting things and arrive at that "more than the sum of the parts" result.

So, this is set up so that all of the main aspects are amply demonstrated. The top row is all audio, middle is all modulation, and the bottom is all control. Here's what's here...

Top row: This starts with a Cavisynth module, their Bufflide...this contains a 1-3 buffered mult AND a slew generator for portamento. Then there's TWO Plaits, because you want to show not only how these work, but what happens when you put two VCOs together and slightly detune one, or to show how you can tune one VCO to a fundamental and then use the second to add the harmonic content (very Plaits trick, that). After that, a dual ring modulator from Tenderfoot (basically, the same passive ringmod module I have hiding in two of my routing patchbays), then a Veils...which comes before the filters because you can show how to "strum" VCOs via modulation signals. Then Ripples, and a Nonlinearcircuits Dual LPG...because it's very useful to use a VCF for "broad" filtering and then use an LPG to contour that into individual notes, or to use the LPGs with some noise (see below) for percussives. Then the audio processing...a Tiptop Echoz provides delay methods, and then the Beads does its granular thing. Last thing there is an unbuffered mult; normally, I'd leave these out on a small build, but it's worth having it here to show how you use these.

Middle row: Quantum Rainbow 2 is a brilliant way to show what "noise color" is about, plus what you can do with the different noise weightings. The Shifty functions both as a sample-and-hold (in single mode) or an analog shift register so that you can "carry over" CV values based on timing and get quasi-polyphony. Stages is next (very useful pairing with the Shifty, also) then the Batumi + the Poti expander. After that is a Happy Nerding 3xVCA, which gives you three linear VCAs for altering modulation signals, then a Shades for polarization, mixing, adding offsets, etc. And Maths. Yeah, you said "no Make Noise", but...well, Maths is what it IS. Not only is it popular in Eurorack, but I think Tony's redesign of the Serge DUSG is a staple in synthesis in general these days, and therefore, it should be in this instructional build. And after it, you'll find an Intellijel Dual ADSR because, while you can get other envelope behavior out of the Maths and Stages, it'll be important to have proper 4-stage EGs in here for both musical and instructional purposes.

Bottom row: An Intellijel uMIDI gives basic MIDI control over a single voice PLUS clocking and other MIDI CC value outputs. Then, yep, Pam's...not only as a clock, but also as a pattern generator and a few other things. Then the next several modules are for screwing around with what Pam's is doing: an Intellijel Diode-OR allows combining of pulse signals, a Ladik Dual Delay gives you two channels of clock pulse delay, then two Doepfer clock mods give you various clock division schemes or multiplication/ratcheting, depending on which module you're talking about. Then Frequency Central's Reset Simulation is a brilliant Boolean logic implementation that not only shows what Boolean gates can do with timing, but gives graphic examples of what the Boolean states actually look like. And of course, if there's a Boolean module, there's a sequencer...and I went with Xaoc's Moskwa 2 and their Ostankino 2 sequencer control module for a robust but simple sequencing environment. After that is your output modules: another Veils for VCA control over audio levels, then this feeds a Doepfer A-138s to allow stereo panning and manual level control. And at the very end, the Happy Nerding Isolator not only gives you output isolation and a ganged stereo level, but it also contains transformers for the isolation function...which you can "punch" a little to warm up a signal, a very worthwhile little trick that should be taught.

The basic idea here was to use as many "big name" manufacturers as possible...not because I'm down on boutique builders, but because I wanted to make this as "bog-standard" as possible, so that anything learned on this will translate decently to systems built around more esoteric modules. So the only "might be difficult to get" module here is actually that Cavisynth Bufflide...which, if that proves to be the case, can be fixed by using a Ladik C-015 in place of the Bufflide and then you'll move the passive mult at the right end to the left end and switch it out for a 2 hp buffered mult. Otherwise, much of this is either fairly close to "off the shelf" or, such as in the case of Ladik, it's from long-running, experienced smaller makers. Annoyingly, this build wasn't "cheap" as such (it sort of is for Eurorack in general, though), but it should be simple enough to implement if the funding is there, and it should be a worthwhile educational synth for many years to come.

Now...about that case. Yeah, three rows...at 84 hp. Basically, this is designed to go in a Doepfer LC9 case (which is only a whopping $36 more than the Palette 104). And the rationale there is that the LC9 cab is a big ol' chunk of MDF wood...into which you can drill a hole, attach a large eyebolt, and then padlock a chain onto that, assuring that this synth ain't goin' NO WHERE without that key. Knowing how equipment in academic situations can mysteriously "grow legs,", I felt that this was extremely important to implement...and the "gravy" here is that the three-tier cab effectively shows the primary division between audio, modulation, and control sections of a basic 21st century modular rig. Should work if the $$$ can be made to work.


holy crap... thanks so much for taking the time to put this together!
The three row logic makes sense, and even as a beginner, I can recognise most modules.
Also good advice on the 2600. We could swap it for the M32, but the lack of a "traditional" sequencer might be an issue. Also the boss has an aversion to anything Behringer, but I could always make a case for buying the Korg FS.
On "losing" the palette, I hear you, but mobility is a requirement. Other than class teaching, we do some community workshops, and would need to take it along. Perhaps splitting it over two palettes would be an idea?
We have ways to limit the risk; the studio's keys need to be booked by individual students, and most hallways are CCTV'd. Dystopian, I know.. yet another joy of academia..

Thanks again for the advice. I'll go put on my best smile before telling the boss we need to double the budget.


I think the Korg FS 2600s are unobtanium

really a 9u case is not that big 3u is about 13,5cm

make sure you get a case with decent handles and a lid and you will be good to go (doepfer briefcase stye for example) - unless you are expecting the modular to be portable by small children


I think the Korg FS 2600s are unobtanium
-- JimHowell1970

Very much so. And the upcoming 2600M isn't the same synth, since it's missing the 3620 modules. Losing the keyboard is a tad inconsequential, but without the extra LFO, clocking, interval latch, etc etc, you've got "crippleware" when compared with either the 2600FS or the B.2600. Yeah, Uli's behavior makes me cringe A LOT, but they did manage to nail that redux.

As for the portability, it's there...an LC9 (or the standard Doepfer ATA cab version, which is more expensive) is really about the size of a curiously-symmetrical attache case. Even without the lid, it'd be a simple thing to transport with just a hefty handle attached (ie: bolted thru) to the top. Plus, no wallwart or brick to deal with, since the Doepfer cabs are internally-powered.

As for appeasing the boss, well...when you present the design above, point out that it was designed by one of Karlheinz Stockhausen's pupils...which would be 100% accurate. Studied with him in 2001 and 2002, and lemme tell you, if you wanted your brain to explode, that was the Express Route!


All golden advice, thanks fellows. And kudos on surviving being Stockhausen's student!

The boss likes the system, but we'll have to split it in two phased orders. In the long run this means more modules, as we can fill two LC6s.
Here's what I came up with
ModularGrid Rack

Some of the modules you suggested are tricky to source in the UK (largely thanks to Brexit...), and the budget needs to be spent quite soon. So I went with what's on offer currently. I like the Isolator, but I also read good words on the Befaco output. Unfortunately no Maths or Beads until the autumn, so I added a few bits for s+h.

And yes, you convinced me on portability.
Am I right to thing that the Doepfer P6 is somewhat bad value, considering the LC6 and a made-to-fit flightcase would be cheaper?

Thanks again to both for the advice, incredibly helpful!


the P6 is much more expensive because of the case fittings (tolex, handle, corner bumpers etc) - and it's a lot more convenient than an lc6 and a flightcase - plus it's less storage space for the lid of the case than for a flightcase


P6 isn't a bad idea...it's just that, if you try and build that build above in there + the M32 (seriously, keep that thing in its own cab), you're going to need TWO P6es. Then this comes to $1060 for the pair of those alone, whereas with the LC9, you have the entire teaching rig in one case, and the cab cost is $435. Even if you had Thomann make a flight case for it (via their custom case service), you'd still come in lower with the LC9. But for moving the cab around the department, you won't really find the flight case all that useful.


Agreed, the P6/9 seem bad value, L6 and Thomann case still comes £100 less.

I know what you mean about having everything in one LC9, but we simply can't order the whole rig, we need to split it over two year's budget. In the long run, it means another 84 Hp row to fill in with toys, and please feel free to throw in some ideas! Something built around Elements sound good, been looking at Metropolis too, but it might be redundant if a Shared System arrives later. And yes, the M32 will stay out, I was just trying to get rid of that annoying cat..

Thanks again for your advice, certainly appreciate your kindness to a newbie!


Ahhhhh...you tried to defy the MG Kitty! Living dangerously there...

Hmmmm...OK, let's see...if the build from earlier would take two years, and there's a car driving 60 MPH halfway between Cleveland and Chicago, and it's a Wednesday in October, then my hat is actually orange. Oh, wait...

OK, given that the build was double what it ought to be, let's screw with it some. Gonna play "How low can you go"...

EDIT: OK, I scrunched this somewhat, managed to drop the cost by $700-ish AND added more neat functions:
ModularGrid Rack
The top row got changed a lot. But it got even more entertaining. First up, the Bufflide got removed, but this allowed me to add the polyphony adapter for the Xaoc Odessa, which is now the main VCO. This sucker's WAY too complex to explain here; go and have a look at the specs instead. And then, for two more oscillators, I put in the mkii version of Klavis' Twin Waves...very useful devices, as they not only are wavetable VCOs, they also have internal quantization...meaning that you can create single-voice patterns from LFO curves, etc with a bit of patching creativity. I put a replication of the final mixer modules after that so that you can generate a stereo submix of the oscillators to feed to the Olivella stereo SVF, and then this passes to the Beads. So there's still that subtractive aspect there, but now you've got some rather potent digital VCOs to feed it.

Middle row was not spared, either. I put in an Erica Black Modulator v.2 for noise, sample and hold, and an extra LFO. Tides was added for a "slow" modulation source. VCAs, Maths...and then an interesting attenuverter module from ADDAC that can also output sum and difference voltages from thruputted modulation signals. This should allow the modulation aspect to get even MORE complex...while still saving a bit of $$ there. Then I put in the current "do it all" modulator, Intellijel's Quadrax and its Qx expander to allow lots of complex internal and keyed external behavior. And there's still two ADSRs there, courtesy of Doepfer's A-140-2.

Bottom row antics saw me change to an Erica two-voice MIDI interface and the swap of a Temps Utile for the Pam's. Then there's six channels of clock manipulation via a Shakmat Time Wizard. Pulse delays next, then the Boolean logic, and THEN the diode OR for pulse combination. The rest of the row is otherwise unchanged.

It's not the simplest thing to try and "down-budget" from a previous build, but it CAN be done. As mentioned, this shaves about $700 US from the cost that I can see here. But it's approaching a zone where I wouldn't want to cheap it down further, because beyond this point you're likely to see compromises in functionality that would make this less of a teaching/lab tool and more like a personal instrument, and this probably shouldn't go in that direction.


top stuff sir! thank you very much for all your help. I'll make sure to post the system once it arrives