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Well, if that's the idea, then there's some problems right off. First up: no signal input. This is a big problem for the external processing function, since you'll need to boost signals up to synth levels to work with them, and nothing here does that. Also, whatever you get for that function also needs to have an envelope follower as a matter of course; envelope followers track the dynamic level of a signal and convert that signal level into a control voltage that can be used for things such as filter cutoffs, VCA controls, etc. Necessary. Very.

Mixing via the Optomix is possible...but really, you need a second mixer (preferably with VCAs) here as well. It's not enough to just mix audio in a modular, as you can get very useful results from mixing different LFO/envelope/etc CVs as well, creating composite modulation signals from that.

Disting is nowhere near useless. It simply does too much to call it that, and for small skiffs like this, you need major multifunctionality. If I were to term something something I see here as 'unnecessary', it might actually be the Just Friends, but a lot of that is due to Mannequins' trendy psuedo-babble that they use to describe the module's functions...as to which, I would like to quote the great thespian Samuel L. Jackson: "ENGLISH, MOTHERF***ER! DO YOU SPEAK IT!?" Seriously, if I have to pull out a copy of 'Psychology Today' to figure out what a module does, I call that 'fail: major'. Anyway, terminology aside, you might even consider TWO Distings, considering what Expert Sleepers jams into the 4 hp they occupy.

I'm gonna tinker with this a bit...but I'm also going to presume that this isn't a powered skiff, and add a power supply just to be on the safe side. If you don't need that, then I suggest dropping in that second Disting, but this'll be done with only one:

OK, now that's solid. Notice that there's a bunch of itty-bitty modules here now, but the functionality is jacked way up. The optional P/S is at left, and like I said, if you're using a powered skiff, just replace it with another Disting and put that next to the one that's there.

External input: added. Morphagene and Telharmonic, as the heads of the signal paths, are right of the Disting(s). Then things change a lot. Next up is a Happy Nerding 3xVCA, which allows you to use the VCAs together in mixing or separately, as needed. Next, I mashed the Maths down to two of its contituent circuits with the pair of Doepfer A-171-2s, saving 4 hp. Waveshaper next, then a pair of modules: a Doepfer A-121-2 multimode VCF (which outputs all modes on separate jacks) and a 2hp mixer, which allows you to mix the VCF's outputs to get some very weird filter voicings. Same space as the Sisters, but still quite strange and cheaper. Then more VCA/mixing, and two FX processors, a 2hp delay and an Erica Pico DSP, which also serves to stereoize your mixed mono signal, so that you get a stereo signal out the right side with that Ladik output, which also has metering and separate inputs so that you can run the Morphagene path out through one, and have the Telharmonic voice on the other.

This thing is capable of some pretty nutzoid stuff, even with the minimal modulation section, due to the Disting (maybe two) and extra VCAs. As far as multiples go, my suggestion is, like with any small skiff, to use inline multiples or stackable cables and just be careful not to connect outputs to outputs. Should work...granted, it's a bitch trying to cram two different signal paths into 104 hp, but it IS doable!

EDITED Mar 27th 2018, 00:00

I don't have such a problem with using the computer to manipulate controls, etc, probably because I've been doing that so long I either don't notice, or VCV's UI coding is good enough that it doesn't drive me up the wall. As a basic learning tool for the underlying concepts of modular synthesis, I'd have to say that it's unparalleled at this point. Everything behaves like it should, albeit up to a point.

That point is, as I noted, when VCV Rack runs into its processor limitation. And I wasn't too pleased when I got a snarky reply from the developer as to the possibility of it having multiprocessor capabilities in the future. To me, that's a problem, and it's also a problem when the primary developer refers to a professional musician as a 'layperson', as if the point of the VCV project is the coding and not the end-use. It struck me as unprofessional, and gave me certain concerns for the long-term usability of VCV at a large-scale level if the intentions don't involve creating something pro-grade. For cobbling 20-30 modules together to do virtual basic builds, it's fine. But if I want to construct something extremely complex and sizable as to scale...as I've found...it's not going to work after a certain point because timing issues, severe audio glitches, and the like begin to creep in as it hits the top-end limit of the sole processor core it runs on. That's unacceptable as far as I'm concerned.

Consequently, I've been doing a lot less long-term work with it over the past week, after discovering that critical limitation and the developer's apparent unwillingness/inability to address it. I'll keep an eye on it, however, and hopefully this will get dealt with by the time we reach the 1.0 iteration...but I'm not holding my breath.

As for the Behringer Neutron...again, not holding my breath. It took them quite some time to start delivering the Model D in any sizable quantities after making it 'available' to retailers, and despite the fact that some beta users have prototypes, to me, that means nothing. My suggestion would be to avoid Uli's vaporware and instead look at patchables from manufacturers that put product out, instead of teasing about it until hell freezes over; IMHO, Uli Behringer needs to shut the f**k up, quit trolling certain forums to cadge marketing ideas, and stop doing cheezeball renders of 'new products' and hyping his 'development' of things that, frankly, already existed and which shouldn't require much 'developing' in order to bring them up to speed for the 21st century.

Not bad...but yeah, the cab will need to be a powered one if you stick with this size. Also, the output module's a couple hp wide in this. My suggestion: Ladik A-540. Also stereo to 1/4", plus you get a little level meter on there.

I still think that going to something larger, such as a Tiptop Mantis or an Arturia Rackbrute 6U, would be a good move, tho...

This actually has all of the basics, although you might find it useful to look into a smaller LFO module. That Fonitronik is huge, and takes up room for some other modules that could push the build a lot further. 1 x 84 isn't much space, so shrinking things down as much as possible is important. Alternately, you could also look into a larger case if you've not acquired this one pictured yet. That would open up space for a couple of other VCOs (important for getting things to sound 'fatter'), maybe some waveshaping to dirty up the sound a bit, a few useful utilities such as mixers, mults, and the like, and also a few more VCAs to enable control over both audio and CV levels.

But as a base-level emulator for a 303...yeah, it's got that covered.

Polka, huh? Well, that could be several places, but a couple of polka-crazed areas are also key to modular synthesis. Wisconsin gave us the Wiard system and Grant Richter's module designs, and it's the current home state for Serge/STS. As for Minnesota, Foxtone in MNPLS now controls Buchla USA...so polka is no bar to modular synthesis!

OK, so let's presume an Intellijel 7u...hold up...

Hmmm...this isn't half bad:

OK...the tile row is now filled nicely. uMIDI to take advantage of the rear-panel MIDI/USB jacks, buffered mult for future expansion CV sending, QuadrATT for extra attentuators/mixing, a digital reverb, and the Intellijel I/O so, again, you can take advantage of the built-in 1/4" jacks.

Next row is all your stuff, arrayed more like a 'voice' with the trigger control and mult at one end and the Frames mixer at the other.

Third row is where I got busy. I added a master CVable clock, S&H/noise, and clock divider. With this array, you can divide the master clock for different tempi to the sequencer, the M32's sequencer, and the S&H if you so decide, or any combination thereof. Batumi (with the Poti control expander) adds four LFOs, and a Doepfer A-171-2 gives you a CVable slope gen for an extra envelope, LFO, slew gen, or what have you. These Serge-derived modules are super-useful for buttloads of functions.

Next to that, two more linear-only DC-coupled VCAs for processing control voltages and the like. Then the Dual ADSR, with that being the end of the modulation section. Next to that, an uMod II, which can be used for ring modulation, certain logic functions, or as yet another VCA. Polaris is next in the chain as your other VCF, with the Veils in position for mixing and/or more CV control right by the Clouds to do your granular manipulation before sending its output upwards to the Frames, then on to the I/O.

Layout seems right...the signal flow should be really clear, making it easy for both studio and performance work. And the M32's patchpanel is about dead-center to let the M32 be the primary 'voice', allowing it easy patching to any of its surrounding modules. Normally, I might've put this on the bottom row to get at the chiclet keyboard on it easier, but somehow, this makes more sense from a signal flow standpoint. Not too shabby, I think...

EDITED Mar 23rd 2018, 01:02

Yep, love the Quad VCA...it also increases function density, which is critical if you're doing a 3u skiff like this. My advice for going further would be to jam maximum function into smaller space (hence the Quad VCA) and save the large hp spans for very specific functions that are must-haves.

As to a filter that fits this bill, my suggestion would be a Doepfer A-121-2 followed by a 2hp Mixer. That way, you get the multimode filter, but with the added mixer, you can combine response outputs for some elaborate sound manipulation, and the whole mess fits in only 10 hp.

But go small and powerful...there's quad LFOs that fit into that Dual LFO's space or less, and those would be better options with the limitation the skiff causes, and so on. Also, see if you can locate a powered skiff, such as the Erica 84hp skiff or MakeNoise's powered 104hp. That way, you take the power off the patchpanel and gain another 4 hp. The more space you can free = more space for possible functions.

My experience with VCV has been rather different. Apparently, the software isn't multiprocessor-capable, and it runs into critical limitations when it exhausts the capacity of a single core among the 16 that it should have at its disposal here. If it could use the rest of the capacity, it would be an outright monster...but in its current iteration, it's best kept to simple builds, especially if any of the sample-based modules are in use.

I like the idea, I like what it could represent...but that limitation is a serious problem for me.

Yeah, this status change makes no sense. The S-180 is the core of their entire sequencer system, and Ladik doesn't discontinue things until they have a successor to the discontinued module, then they yank the prior version from their product list altogether (check the C-040 and C-041 for an example). If that status is wrong, it needs confirmation...then fixing.

First question that comes to mind is whether this is an Intellijel 7U or a compatible-with-everything-else 7U. There's a big difference in how to proceed with this build between those two, and the options they give aren't mutually-compatible.

Otherwise, Braids and Clouds don't exist in those forms anymore. Clouds only exists as third-party builds in a different size, and Braids has either been replaced by its v.2, Plaits, or exists as a third-party build as well with the original circuitry. Unless you have the originals of these on hand already or are 100% certain that you can get them second-hand, it's best to remove them altogether and replace with the present-day options.

Second...why two power supplies? 7U at 104 hp isn't totally huge, and one of these Tiptops alone does 2 amps at +12v. The -12v spec is a little...ah, lacking, but unless you're exceeding 500 mA on the -12v rail, having the second one is unnecessary. If this IS an Intellijel cab, also, the cab's already powered with a supply that way exceeds the Tiptops, but given that that's unclear here, it's hard to tell if you can lose both supplies or just one (or better still, put one in with a better current balance across both 12v rails).

m1sterlurk's spot-on about the Quad VCA, also...saves some ca$h over the Veils and you can free up its VCAs with a couple of little submixers for that duty. And the thing that jumps out at me as a problem is that there's a lack of cycling modulation sources here, such as LFOs, a function gen, etc. Granted, the Dual ADSRs can cycle, but that plus the M32's LFO isn't going to properly feed all of the modulation-hungry stuff in here.

If there is, it can't be too recent. This system's got five discontinued modules in it, for one thing. I tried riffling thru the magazine's back issues and got nowhere when doing a bit of searching, but unless your Japanese isn't up to snuff, the article (if it can be located) might not be all that informative.

Hey, the sheer allure of 13 x 84hp is hard to pass up! Can't blame you there...

Yeah, saw that build in the other thread...it's a LOT tighter now, and with the plan to expand, it's going to grow into a veritable kaiju monster of noise over the next few years. A helluva start, to be sure!

I'll second the importance of having some other CV sources...take a cue from m1sterlurk and look into snagging an SQ-1. At $100 for a 2x8 sequencer with internal clocking and a few other tricks, it's a quick and cheap way to kick the functionality up even further. You can even use sequencers as multistage envelope generators, user-definable VCOs (if you can clock them at audio frequencies), and a bunch of other interesting things, some of which do require a couple of other modules, but hey...they don't call it EuroCRACK for nothin'!

m1sterlurk's 100% spot on here...this system has an awesome compliment of processors, but very little in the way of sources. While the Braids is a really great oscillator in of itself, having just one single audio generator isn't going to work well unless you're talking about a very minimal system build. Another problem that seems present is that some of these space-heavy processors are a bit redundant, notably the Morphagene and Clouds which are both granular sample/audio manipulator devices. If you were to let one of those go, you'd open up another either 18 or 20 hp (depending on what gets pulled out) and then that would give you more space for a bit more sources. Although, I'll second that vote for the Dixie II+, but put one of those 3-in mixers next to it to use as a handy waveform combiner to stretch out that multi-waveform oscillator's capabilities.

I'm also not a huge fan of Pittsburgh's first-gen stuff, so a different and more capable filter might also be a consideration. Hrmm...gimme a bit, gonna tinker with this...lessee...(exeunt stage left)

REMIX! C'est voila...

OK...I did some radical surgery on your original here. First up, I reworked the tile row's positioning to work together with the reconfiguration, putting the MIDI on the left above the VCOs. Buffers are next to this. Other buffer went away (redundant) along with the MakeNoise mult (too big, replaced with 2 hps for twice the mults in the same space). Modulation/S&H tile is now above the modulation sources, and the audio I/O is rightmost, again to follow the signal flow pattern with the processors now on lower-right.

VCOs are the Braids and two Dixie II+s which now have the mixers as waveform combiners as well as mixpoints for the Braids' output. This is a pretty critical rework, as it now gives you three signal sources, meaning you can use one for audio frequency modulation on the other two, and still have those two for a more complex audio source.

Audio flows down to a Morgasmatron, which is a very twisted take on the Korg MS-20's filter pair. The Pittsburgh VCF just didn't have the modulation inputs to do some really wild stuff that the Morgasmatron does easily, plus the M'tron is a dual-input VCF with a MIX output, which means you can also use this to mix audio as well, albeit with some strange stuff going on. Warps is next to tamper with the audio, either from the M'tron's MIX output or its individual filter outs, allowing you to further combine those down while processing them at the same time.

The Quad VCA is dead-center in the bottom, which allows you to easily use its VCAs for audio OR CV amplitude control. You can mix two audio signals together on VCAs 3 and 4, but still keep 1 and 2 free for DC-coupled linear work.

Morphagene is gone, as you'll note. As I noted above, it's redundant, and you don't want a lot of the same processing things in a small build like this. Kept the Clouds, which has the Erbeverb as its front end. An idea I had is this: take the mono feed from the Warps (1 + 2), feed that to the Erbeverb's mono in, then use it to generate a stereo field to feed the Clouds with, and the Clouds' output goes direct to the I/O above. So, technically, a big chunk of the middle of the audio chain is where the mixing gets done, in increments, until you hit that last processor pair and tamper with the mixed audio plus create the stereo field signal to go straight to the outs. Also, bringing the inputs in is a bit easier now, since they can come in either in mono to VCA 3 while VCA 4 handles the generated signal path...but that's just one method, and this creates several, now.

Above the processing is modulation: a dual ADSR to better deal with final VCF/VCA envelopes, the Maths for loads of definable modulation, and a Batumi for four fixed-waveform LFOs. Plenty of modulation signals now to feed the various modulation-hungry changes!

Anyway, this is how I'd approach the situation. Yes, it means swapping some things out and doing some radical surgery, but this is a much more capable build, starting with the bones of yours...and it had pretty good bones, just needed some reworking. Another suggestion (which m1sterlurk's on below) is to study experienced synthesists' builds, and glean information from seeing things that those people tend to do in common...because they work. It's also best to do and do and redo and redo and redo again and again here on MG before pulling the fiscal trigger for a system, because you can both study up AND learn how to make, then avoid making, mistakes.

EDITED Mar 22nd 2018, 02:28

Oh, yeah...it's a beautiful sound when you 'ring' things like that. On one thing I've got on Bandcamp (and hopefully elsewhere later this week, finally) entitled "Beneath Puget", I got the theremin on the track to 'ring' its processor chain...and it's the trippiest moment when that final pitch keeps building and getting purer in tone, then rings off into the background layers. I still recall that happening when I was cutting the track about 18 years ago, and going 'wowwww!' when that ring-off happened. Love it when those 'happy accidents' pop up...

You're welcome! I figure that after 40 years of prodding various electronic devices into musical service, it's probably time to start 'paying it forward'. After all, I definitely think that experience squandered = knowledge wasted.

Hmmm...what to do. Well, actually, I'd opt to take the Shared+ out as well, as it's not overly huge and the case makes it very portable, especially compared to some of the modular (and buttloads of other) stuff I've been known to drag out for live work. You can certainly find a sizable case that can house the laptop and skiff, and the Shared+ is in a metal briefcase-ish thing, and I think you'd still be able to drag along the line-lump supplies and a pile of patchcables in the bag with the laptop and skiff. It'll just take some ingenuity.

OK, given that plan and sticking with Mutable stuff, I'd opt for an Elements and a Ripples once the Rosie's in the Shared System+. MakeNoise doesn't have any of its modelling toys in the Shared Systems, such as the Mysteron and Telharmonic, and the Elements' sound would be killer against the other west coast things. And having a multimode filter is still important, because even Don Buchla figured out that some sounds just need subtractive tricks to make them work, ergo he even eventually came out with a multimode VCF, albeit as quirky as you'd expect from Don. As for a Clouds...nah, not in this case, since the Morphagene does a lot of the granular mangling, plus you have the Erbeverb as well. But everything seems fine; you even have the requisite VCAs in the Shared+, in the form of the Optomix (LPG) and the Modemix (you can use that as two DC-coupled VCAs in a pinch by using CVs, etc as the modulator signal). The only thing I kindasorta wish was in the Shared+, tho...a Brains, because then you can also sequence up that Pressure Points with it, and it's a natural combo alongside the Tempi and Rene. Maybe if you use a big enough hammer to try and fit it in there...?

Yep...as suspected, high abuse potential. Love the 'irreparably-damaged bouzouki'-type racket the Mysteron's doing there, especially when it hangs up on that higher note in the pattern. The distorted, metal-screechy parts when the sound goes into that overloaded-signal type of distortion is excellent! That's going to be an interesting little rig...

Damn...that's nasty sounding! You oughta retitle it 'Ghetto Grit', 'coz it's got that dirty, dusted-out, defective f**ked-up sort of sound to it. Just needs that Miami 808 BOOOOM! and that thing's done! Nice!

Well, there's the Erica Pico Out...that's a 3 hp stereo out module with a headphone amp. But trying to cram both functions into the same remaining 3 hp will be virtually impossible. The other idea would be to use a Erica Pico CV Mix...this is a DC-coupled 3 to 1 mixer, and with that you can mix both audio and control voltages. CV mixers have to be DC-coupled, since you can't pass extremely low frequency signals such as LFOs or DC voltage values via an AC-coupled mixer. Those are for audio only. The reason I'm suggesting that particular mixer is because you can use it for mixing modulation curves out of the Maths when you need to do that, or for an audio mixer when that's called for.

As for using the Moogs as outputs, there are several points into which you can patch on the M32 to put a synth-level signal into it as part of its signal flow. Probably the best points for audio would be one of the VC Mix inputs, probably the HPF patchpoint (Mix 2), as that lets you keep the low-pass engaged for your M32's signal and you can CV the mix between that and the audio signals on the rack. As for CV signal patchpoints...anything that notes that it's a CV function on the M32's patchpanel will take a CV or modulation signal. So for example, to modulate the LFO's speed you'd patch in a signal from one side of the Maths, set that up with the slopes you want, config it to loop, and then your M32's LFO time is sweeping up and down. The DFAM has similarly-usable patchpoints on it also. Not quite sure, however, if the Moogs want to see line-level audio or synth-level at their "Ext Audio" patchpoints, but a bit of experimentation can sort that out.

Best thing I could suggest is: study this site. This pretty much IS the compendium for everything modular on the Internet with the exception of cases, which are one of the few parts of a modular synth that MG doesn't cover. But if it goes IN the case, 99.9 times out of 100, it's here. But read up on what the basic modules do, for starters. Muff Wiggler: also helpful, plus spending some time on Doepfer's website seeing how their modules function (Dieter is good about going into detail) isn't a bad idea at all.

As for taking up space, you will find...sooner or later...that electronic music equipment somehow breeds like rats and overtakes everything. Expect it.

Actually, you should only have 3 hp left, which is actually a bit worse than 4.

I'm looking at a build of what you're describing here, and it seems to me that you may have painted yourself into a corner, so to speak. The problem stems from a couple of things:

1) The Moog synths should probably stay in their own cabs. That way, you have them under their own power supplies, and they have their own audio outs (and can be used for the Rackbrute's audio out, in theory). This would then free up 120 hp in the Arturia cab. Plus, the DFAM + M32 combo in Moog's double-cab stand looks ass-kickin'.

2) You seem to be falling into the 'sexy module trap'. Yeah, some of these might look really killer and seem to pack loads of function if you base that concept on module size. However, this is a real problem, because both assumptions are often pretty wrong. Now, I will note that in the case of the Maths, it's a correct assumption...but maybe not so much with the Chord. While it looks like a must-have, it's actually more of a specialized device. It's also 28 hp, which is a bad idea for inclusion in a limited space rack. If this were something designed specifically for polyphonic use, which is what Qu-bit's quad stuff excels at, that would be a good choice...but then the Moogs would be a lousy choice. Or if you were doing a lot of sequencer-based generative stuff, the Chord would be awesome, but that doesn't seem to be the point of this cab.

The truth is, you need to be looking at smaller modules if you're going to go for maximum function in a 2 x 88hp cab. And you also want to look at what I call 'boring' modules...because in of themselves, they might be boring, but in tandem with one or two other devices, they open up those devices' potential massively. And again, these same 'boring' modules can also open up the Moog devices' potential.

Case in point: a comparator. Ladik makes one that fits in 4 hp, looks boring. Just emits a gate in a few ways when a voltage threshold gets crossed. Ho-hum.

Now, take that same boring comparator and feed a weird CV curve into it off of the Maths. Send the gate to an EG that treats an incoming gate as indicating a 'hold' state. Now, feed that envelope to a linear VCA that has a CV out from a sequencer passing thru it so that the envelope controls the VCA's passing CV level. Now, send that resulting voltage on to a VCO, but gate the VCO so that audio doesn't pass when the comparator's level is 'low'. OK...now jam all of that activity into only 16 hp.

Impossible? Well, I'm looking at that very thing in this other browser window over here...

Yeah, some modules look dull, some seem like they're too small to do the job, and so on. Not true, though. This is just a basic example of what presumably 'underpowered' modules can do, in conjunction with other sleepy-looking stuff.

My suggestion...like I said, re-cab the Moogs and free up your space. Keep the two modules that you do have, and figure out how to anchor an auxiliary cab around them, one that compliments the functions of the Moogs. But before doing that, spend some (a lot) of time on MG studying others' builds, and spend a lot of time with the Moogs to discover their strengths and weaknesses, and how each could be made better by subsections in the Arturia cab build, keeping your module sizes small to jam maximum function in minimum space. In the end, you'll wind up with a much more powerful system with a lot more complexity and capability.

Ala-pnutbuttersammichez!! KABLAMMO!

Most of the audio is up top, with the buffered mult for CVs to the far left. Morphagene is last in line to screw around with the results from the Lifeforms, Drums, and thruput from the Rings.

Bottom row is initial clock-in devices, then the Rene. Quantizing and arpeggiation to the right. Then the Maths for screwing around with modulated parameters; this also allows your sequencing and mod patching to go 'up' to the voicing. After that, Disting to mess equally with CVs, modulation, and all of the other stuff it can do. Last 'voice', the Chord Organ, is right next to the Rosie mixer to easily hook it in as a crossfade option, plus it's near the quantizing, Rings, and Morphagene for easy abuse purposes.

P/S got moved to the lower row, since it's movable, and having its power inlet on the lower left with audio outs on the lower right seemed ergonomically sound for cable dressing. And I even added the 1hp MakeNoise blank right next to the Rosie, where it looks perfectly natcheral. Howzat?

EDITED Mar 19th 2018, 01:52

Not a bad idea, that...Arturia really hit a home run with this system. Built-in handle, mateable to the new Minibrute 2 versions or another Rackbrute, and the whole mess folds up with the support stand turning into a handle for the whole contraption. But the reason I was thinking that might work is that you can attach the Rackbrute to a Minibrute 2 or 2s, letting it sit on the stand, and then have the Rackbrute on its attachment above the Minibrute. However, I'm not quite sure how the back supports of the Rackbrute stand will work on a typical keyboard stand; my plan is to have it on a flat surface, which is how I'm usually seeing it set up.

It's a great way to mangle CVs...as you'll see, the acronym means Shifting Inverted Signal Mixer. It's just as crazy as the sound of that implies. I'd have to say that as far as CV mixing/modifying devices go, this might be the do-it-all in 12 hp device. Even more twisted is that it can also do offsets and it can be used for audio in some strange ways. Lots of custom configuration jumpers, too.

That's already a damn interesting compliment of modules...yeah, do the Varigate 4+, for sure. Also, fix the mixer and VCA lack with something like an Intellijel Quad VCA...does both with a lot of configuration options and the price is right on it. That way, you can make the uVCA exclusive for CV use and only use an extra off of the Quad VCA for CV duty when absolutely necessary.

Another sick and twisted mixer idea: a 4ms SISM...? Could be entertaining for scrambling CV signals...

From the examples I've heard, the A-106-1 is every bit as capable as the v.1 MS-20 filter (same as both MS-20s I used from the end of the 1970s to the mid-80s, then from the early 90s until this past year) which is the same as the Mini (and, I'll also note, the Mini sounds like that first MS-20, fresh out of the box in 1979; many people claiming the Mini doesn't sound like a 'real' '20 are not taking component aging into account and probably have never heard one back during its original retail availability)...and those are super capable when prodded the right way. It can boom like a mo'fo in the low end, sound bubbly in the mids, and tear your head off up high. And yes...that's the point behind the A-106-1; Dieter wanted a Sallen-Key pair that was 'more'. The insert point evilness is just the cherry on that cake, but having all of the FM capability already puts it beyond the MS-20's Sallen-Key pair.

One other thing...if you're doing the Rackbrute, have you considered coupling it with something like a Minibrute 2s? The pairing is a natural, plus since your 6u is all voice, linking it with that sequencer + some extra patchpoints for $649 seems like it would make sense. It's definitely on my list to do here.

Schneider's Buro shows the Happy Nerding Isolator on their site, but lists it as 'coming soon' in its status bar. My guess is that we'll see it available right after Musik Messe, which should be in mid-April. IMHO, something like that might be worth the wait, plus if it's in your second buy, it should be on the street by then.

Buffered mults...well, when you need them depends on what you're splitting up the voltage TO. Some modules drop the voltage worse than others, depending on the impedance loading at the CV input. But since we're dealing with three Intellijel VCOs and a MakeNoise Mysteron, I'm not inclined to think that either David Dixon or Tony Rolando would design something with crap loading on the inputs. Generally, the rule of thumb should be that once you pass six splits, then you need to regenerate voltages, but some VCOs...not these, though, I'm sure...can be problematic in a split between just 3-4. If you're still concerned, just drop one of the buffered mults; this leaves plenty of regenerated signal off of just the one remaining. Mind you, the critical need for buffered mults only really comes into play when you MUST have the same exact voltage scaling between the splits; if you're splitting gates, triggers, or non-critical signals like LFOs or other modulation CVs, they're not all that necessary.

ooooo...comb filter! Have I got a filter idea for you: a Doepfer A-106-1. Sallen-Key pair, like in the Korg MS-20, but with a sick little twist: an insert point in the resonance circuit! Now that little detail opens up a lot of weird stuff, especially when you drop a short delay into it like...well, a 2hp Comb. What would be happening in such a configuration is that the regeneration for resonance is being delayed by a teensy bit, causing the whole filter setup to 'whunnnngggggg' very strangely, creating (in theory) another resonance structure in the path. I like this filter...I've loved the nasty, alternately fat and yowling character of the MS-20 for decades (and Dieter claims his version is even grittier and nastier than the original!), and having something utterly insane like that insert is a bunch of plusses. Another bit of filtering bad craziness is the Mannequins THREE SISTERS...formant-structured, but with this odd 'centre' input that causes the formant spacing control ('span') to go into warped FM-type behavior in the filter circuit. Consider: mult your input signal to that, and split one feed off to the Comb, then send it from that into the 'centre' input. Wooooooooo.... Happy Nerding, also, has an unwell filter, the MMM VCF, that allows you to either use it as two ganged state-variables (that also happen to have a 4-pole LP out, atypically)...which you can also feed into each other in various configurations to create some very weird filter behavior, plus the Comb can be linked into that sort of a signal tangle to make things even more unreal. Basically, anything that lets you subvert the normal filter behavior in some weird way or another, like those three examples, might be the sort of thing you're looking for. Loads of abuse potential...just like adding those 2 hp mixers; a little alteration in the way of thinking about the signal flow can yield amazing results, very unlike the things you find in a typical analog modeller.

EDITED Mar 16th 2018, 04:28

OK...I did a little detective work as well. They have a link to what I presume is a NAMM demo (?) image with the Toolbar mounted in the entire 1U row in a Synthrotek Power Lunch case. I was able to sort that out with some closer examination of the case fitments, plus the case's orange color in their pic is a bit of a giveaway. It's definitely 42 hp. The Tonestar 8106 below it is definitely 32 hp, which gives the lie to the spec on SE's website.

...and sure enough, after setting the width to 42 hp, the module now crops out perfectly. Just goes to show, not even the manufacturers themselves are always 100% right!

EDITED Mar 16th 2018, 03:51

Oh, boy...well, first up, that version of Maths is very discontinued for a long time now. Next, there's sort of a lack of oscillators here, and you need several to build up drone spectra. Look at some prebuilt drone devices such as the Grendel line...these have at least two VCOs, and while the Benjolin has those, that module is more of a 'random source' device. Drone synths also don't usually need a keyboard controller, either, and losing that will free up a lot of space for stuff you do need.

I'd kinda do this differently...lemme think about this for a hot minute...

(time passes...not much)

OK, now THIS is a serious drone instrument:

Top, left to right: a set of lo-fi VCOs with a restricted frequency range to build up low end. Then a west-coast-type dual VCO that allows complex cross-modulated timbral textures. A Telharmonic...this gives you the ability to sweep through additive harmonics and a few other nice-and/or-nasty tricks. CVable Fold with subosc divider, and then four VCAs to control different source levels and mix those down to the VCF input.

Bottom: Power supply...I went with an Arturia RackBrute here, because you get 4 more hp per row, a beefy power supply for the size, portability, and it's stoopid-cheap at $359. A dual clock with logic to cause strange rhythmic behavior. Then TWO Maths (current model) because you want lots of complicated modulation for everything in the audio chain, as well as to cascade into each other for somewhat unpredictable modulation behavior. The Doepfer VCF is not only a redux of the Korg MS-20 Sallen-Key pair, it also includes an insert in its resonance path, into which you can add the Chronoblob delay next to it. Or send the audio to the Chronoblob and put the filter in ITS feedback path insert. Either is good! After that, I put in a third-party build of the Clouds module so you can granularly tamper with the audio stream. The output is a Bastl Ciao!, which also allows you to put two different stereo streams in, gives you a headphone amp, and balanced 1/4" outs.

Anyway, that's how I would do this sort of thing...given that I've done a lot with drone techniques, this is sort of a present-day Eurorack build of some of those ideas, but beefed-up with the newer modules Euro has to offer. So it's a decent example to start with, since the overall architecture is pretty proven, but definitely tinker with the idea some more.

(FYI, if the rack looks incomplete, click on it to go to the actual image. MG seems to be beefin' on putting the completed image up at present. Grr...)

EDITED Mar 15th 2018, 22:40

Actually, it seems to be MG doing that. I uploaded a properly-cropped image of it and then listed it at the supposed 32 hp width, and it did that in the same way as the image I replaced. I get a feeling that SE might not have the right width in the specs on their site, because if it were 32 hp, it should look just like the crop I did.

It kind of strikes me that if the intent is to avoid duplicating the sound of the other synths, you might want to reconsider that SE 4075 filter. While the Binary Filter does have some non-typical weirdnesses, the 4075 is sort of a rev.3 ARP 2600 filter minus the high-end dullness. Having used a rev.2 for a long time (basically, what the rev.3 was intended to replace after the Moog lawsuit; the sound is similar, but with the high-end mod done to the rev.3, it's very similar to the original 4015 (rev.1 and 2) which I'm familiar with) the sound is...well, it's that old-school LP ladder sound. However, there's ways to get that and a lot more with some other modules, which could give you a lot more timbral options. Or you could rely on the Binary as the 'typical' filter and go off in some stranger directions to replace the 4075; adding something that does CVed formant filtering, for example, gets you into the general zone of things like the Synton Syrinx, a very nifty and rare device.

Don't think that 'basic' is bad...it's actually quite good unless you already have 'basic' on hand and you're trying to push a sonic envelope with the modular...which would be the right move, as modular is often about pushing the envelope. Now, one thing that could be done to get at that might be to drop the Levels and instead swap in...wait for it...FIVE 2hp mixers. WTF?, you say? OK...look at the DixieII+s for a sec. Each of these has multiple simultaneous waveforms, plus a suboctave out. By putting a 2hp 4-in mixer with each, you then get the ability to waveshape by mixing waveforms, resulting in a much greater variety of timbres even before filtering. And you still have two more left, which could be dropped in most anywhere for either audio or CV duty, since they're DC-coupled.

And speaking of DC...which sucks if you output it from your final outs...you might look at an isolating output. Happy Nerding has this 4 hp thing, the Isolator, which offers balanced stereo outs (TRS 1/4") with transformer isolation and a ganged stereo level control. You'd lose the headphone amp, but given that you pick up ground-loop killswitching plus the nice transformer sound, that'd actually be a plus. It's cheaper, also.

Maybe also drop the mults...the space you're in is a little tight for those to be onboard, plus you don't have enough voltage splitting to warrant buffered mults. Instead, reclaim a little more space and use inline mults or stackable cables like Tiptop's.

As for the MIDI interface that's there (an Intellijel uMIDI), it actually does more than this system needs, such as clocking for a sequencer, which you don't have one of in the build. If you're considering using external conversion with the SQ-1 and/or 0-Coast, may as well boot that out too. Just those two devices alone give you two channels of CV/gate, which is plenty; going for four separate signal flows in this small a space is probably a bit of a stretch.

Last thing I'd do here would be to change up the layout a bit. Try and get your audio chain in one row, the control chain in the other. I can pretty much guarantee it'll make the synth easier to use in the long-term.

Thus far, though, the idea's on the right general track. Now try and see if you can mash things even tighter while at the same time reducing the monetary outlay. I think you'll be able to pull that off pretty easy-like!

It's faster, for one thing; trying to jam too much down MIDI can lead to logjams. Plus, as I noted, not everything goes over MIDI, but all of the synth's functions should be on the USB bus. The FH-1 also allows a lot of user-configuration, which will let you change the module's function for different purposes; you might want its internal sequencing on one track, clocked out of the DM12...or at another time, you might want to convert the DM12's signals into something with a lot of extra modulation and the FH-1's internal processor can enable that by adding the modulation per output. Or if you don't feel like using the DM12 with the modular but still need a controller for it, you can get an Arturia Keystep and that'll connect directly to the USB host port as well, without a need to route that thru the computer. Lots of options there...

I think the Intellijel 7U 104 should be able to handle it provided he uses the optional TPS80WMAX supply board. That sucker's rated for 3A on each 12V rail and 1.5A on the +5. While you could theoretically jam that much draw in that case, I think you'd really have to work at it to find modules that can max that amperage. Even so, I like to suggest that the P/S get majorly overspecced in any build; even if the draw is closer to the TPS30's output levels, it's still better to run the 80WMAX so it can stay cooler, loaf and last longer than heavily taxing a smaller supply.

But yeah...just use a flying bus distro cable off of one header, probably would be best for the tile row since there's not going to be significant current draws up there. As long as you can locate a flying bus with 10-pins for the modules and a 16-pin connector for the bus connection, this should be golden.

EDITED Mar 14th 2018, 20:53

That will only work if the Deepmind 12 can send a clock over MIDI when its sequencer is running. If it has that capability, then yes. However, that's sort of a 'hit or miss' function...some synths do, some don't. However, the Mother32 does have the capability to send a gate pulse from that output point when its sequencer is running, so you can lock the Voltage Block up with that and sync it wit the Moog's sequencer.

As for interfacing the Deepmind with this, though...again, the Expert Sleepers FH-1 will allow the DM12 to directly connect to the modular via USB, since the FH-1 operates as a USB Host, unlike the Doepfer interface which has to connect TO a host, such as a computer, etc. Now, while I can't find a direct reference in Behringer's lit to what gets sent/received via the USB, I'm going to guess that that signal is a lot more comprehensive than the MIDI ports, and likely does include clocking signals so that it can lock up with a computer-hosted sequencer. If this is the case about its USB signal, then not only can you lock the modular to the DM12's clock, you could theoretically clock your entire system via the DM12's clock, and that includes sending sync/start-stop from it to the Mother32's sequencer as well. But you'll need to check on that one spec aspect to make sure.

EDITED Mar 12th 2018, 22:57

A few things here are very missing...first of all, there's nothing that can function as an LFO-type modulation source. Given that the space in this rig is fairly tight, I'd suggest looking into something smaller than the typical 'hits', such as Maths, etc. Instead, look at something such as an Intellijel Quadra. At 12 hp, you get four AD envelopes that can be switched into a 'cycle' mode that allows them to function as definable-waveshape LFOs, so you knock out two things in one shot...a few more EGs, plus your LFO needs.

You have a noise source...that's good. But you have no S&H...that's bad. Sample and hold would allow you to sample the random sources from the A-118 and create random CV patterns when clocking it from the....ohhhh, yeahhh...that's absent, too. So not only can't you clock a sample and hold, the Voltage Block has no clock, which kind of makes it useless. Go and have a look at the matching Malekko Varigate 4+; you're going to need that to do timing duties for everything that needs a clock on here, in addition to the other bits of magic it can do for the Voltage Block itself.

Buffered multiple: lose it. This rig is too small to require it; two VCO destinations won't cause nearly enough CV sag to throw them out of tune/track. Given the size of this build, I'd suggest going with inline passive mult devices or stackable 3.5mm cables such as Tiptop's to split outputs to multiple destinations.

Filters...you went with the 'sexy' options here, and in this case, that's a mistake. While the Three Sisters and the Rings are excellent in of themselves, relying on only those for filtering is rather akin to having too much of the same thing. One of these needs to go so you can replace it with a not-as-sexy-but-necessary resonant-type VCF of some sort. Lots of possibilities there, ranging from basic to really nutzoid, such as Intellijel's new Morgasmatron or the Rossum Morpheus. But even boring-looking things contain surprises, like Doepfer's A-106-6, which is a version of the Oberheim Xpander filter setup...put a small mixer after that to combine different response outputs, and you've got something weird going on!

You also need an output stage; the Doepfer A-138s will still be at synth-level at its outputs, and it's necessary to get that down to normal line-level. Plenty of options exist, some of which also have headphone monitoring, balanced 1/4" outs, stereo ganged master level controls, and so forth.

Last thing I'd kick out would be the MIDI interface. It's...okay...but if you want USB interfacing, there's more capable options. Plus, that Doepfer interface isn't host-capable, so if you wanted to hook a USB controller directly to it, you'd be out of luck as nothing would happen. Instead, have a look at Expert Sleepers' FH-1...host-capable, fully-programmable, expandable (up to 64 outputs!), and has lots of tricks hidden in its firmware. Doepfer's great for a lot of things, but I've never been jazzed about their MIDI devices. On the other hand, Expert Sleepers are kind of control I/O specialists...this is very much their lane.

This is a decent start, but it needs some refinement. Best advice there is to avoid piling the cab up with 'cool sh*t'; instead, think more about 'boring' things that actually jack up the capabilities of the 'cool' modules. Those are the devices that really do a lot of the heavy lifting in a modular build.

It should...but there's a few things you might consider:

First of all, given that the M32 and the Circadian Rhythms are very 'controller-esque', I would suggest putting those in the bottom row to make them easier to work with in that way. The other thing you'll probably want down there would be some type of performance mixer; consider something that gives you VCA control over level, pan, AND fx sends, because you've got some things here that really scream for that sort of fx send-return type of mixer architecture.

Second, use the hell out of your 1U rows. If these aren't Intellijel-format (which I'm betting they're not, given the width of the cab), seriously consider stacking those up with all sorts of 'unsexy' modules, such as VCAs, attenuverters, mults, S&Hs, audio and CV mixers, etc etc etc. Go nuts on those. The more of these basic functions you can add in 1U will result in more complex functionality for your 'sexy' 3U modules, ergo you can stack more of that in for weirder functionalities.

Last, modulation sources...you have the space to get really crazy with that. It wouldn't be too nuts to drop in a Maths, Tides, and something else altogether to give you a really open-ended set of modulation possibilities.

This has some real potential to it...and no, starting with a patchable like the Mother32 isn't a bad idea at all. In fact, I'm currently mulling over a semi-portable Eurorack rig based around the two new Arturia Minibrutes + two of the Rackbrutes...and I've been doing this sort of craziness for abot 40 years now! So if it works...it works!

None in particular...this looks like it'll do what you're intending, even in that tiny a space. As for 'noisy ambient', that's where some creative Morphagene abuse via the Turing Machine and Maths comes in. I think you've got it!

EDITED Mar 12th 2018, 02:15

Yeah, I'll give you that on the envelope issue...however, since you've already got some 2hp in there, why not pull the Dual ADSR and drop in seven 2hp modules...say, 4 ADSRs and 3 EGs? Now THAT would take care of any questions about envelopes for quite a while! The EGs also give you CVable attack and decay, plus a choice of exponential or linear response, so they'd be great for controlling either audio or CV, and having the exponential AD with an exponential VCA would give you some sharp, percussive envelopes. It's definitely a control-dense option, but envelope controls aren't ones you'd often be constantly tweaking, plus the EG's parameters are voltage-controllable, so you don't need to get at them, necessarily.

That's one thing I love about the form factor on those itty-bitty modules...if you have a tight cab but need major functionality, you can go with those as long as they're dealing with functions that're more 'set-n-forget'. The only other thing that comes to mind, looking at this, is you might consider swapping the TRIM out for an AVert...both do attenuation, but the AVert also lets you do inversion, which is super-nice for envelopes and odd VCO/VCF modulations. Beyond that...nothing comes to mind, so I'd say consider those swaps and then get ready to button it up.

Maths is like bacon...it goes great on everything!

Seriously, tho...Maths is probably the best-featured complex modulation source for its price. Yes, it'll work with the DFAM as well as most anything else you might use some type of modulation on. Looking at the setup above, though, I'd suggest that the M32 go on the bottom tier, since it has its 'chiclet' keyboard for input, step sequencer work, etc and it just makes sense to have that in a position where it's easiest to use. That would actually put the open-ended 60 hp cab in either the middle (where I would put it to easily work with both the DFAM and M32) or the top.

So...20 hp for the Maths, 3 for the Pico, 4 for the P/S...puts us at 27, 33 to fill. My instinct here would be to fill that remaining space with modules that can up the Moog modules' game, so...lessee...

Right off the bat, we can open up a new set of possibilities for the DFAM's sequencer by dropping in a quantizer. Since the DFAM was designed for 'drum' sounds, apparently it doesn't have an internal quantizer to properly scale pitches. Which makes sense; if you're creating not-exactly-pitched noises in the first place, you don't need a quantizer. But if you ADD a quantizer in that third cab, then you can use BOTH DFAM sequencer rows as proper pitched sequential sources. And even more twisty, if you also drop in something that can send a trigger on counting specific steps, you can vary the DFAM sequencer's row lengths. Quantizer-wise, the Doepfer A-156 offers a pair of basic quantizers in 8 hp, then for the row-count/switch voodoo, a Doepfer A-160-2 can handle a lot of clock-division counting duties while their A-151 offers up to four inputs switched to a single out. Why four? Well, that also allows the M32's sequencer to play into this craziness! Why not, right?

Hokay...16 more hp down, 17 to go. So...why not mix down both Moogs via the 3rd cab? And in stereo, since you've got that Pico DSP. Again, Doepfer...their new A-138s is an 8 hp stereo mixer, with manual level and pan controls. But then, feeding the Pico DSP's mono input is a little dicey there, so fix this with a Ladik A-410 panner/mixer. With that, you can use the module as either a mono aux-like tap in one signal line to feed the DSP, or you can mix down the DSP's output to pannable mono, and all of this can be put under CV control as well as used manually. And then button up that with a Bastl Hendrikson, which also allows for an FX-send-type stereo tap to insert the Pico DSP in post-mixer, and provides balanced stereo outs plus a headphone amp. That kills the space in that case, and provides both Moogs with some interesting sequential capabilities and a killer modulation source, plus a final stereo mix with FX send and/or returns. Pretty neat, I think!

Except for one little issue: the 'power-on' draw issue. Most Eurorack modules don't have this to a major degree, but there's some major offenders out there. The Roland Aira modules are one example that're particularly egregious, and the vast majority of tube modules (not all, tho) have a big power-on draw, sometimes over twice the normal operating draw.

Even so, a multitude of little power-on issues can accumulate into a big one. My rule of thumb, drawing from amateur radio experience (where current draws can change quite a bit during basic operation) is to exceed a specified draw by at least 1/3rd. So, for example, if your totalled operating spec is 500 mA, make sure you can supply at least 750 mA. The extra amperage won't be a problem (it's a measure of capacity, unlike voltage) and having the reserve will not only avoid power-up problems, it'll also let the P/S loaf along with less heat and component strain, making that part of the system last longer.

Actually, the Dixie II+ is an excellent choice, it packs a lot of capability into that space. The only thing I might ding it for is cost, but considering the functionality jammed into it, you do get your money's worth. However, you might check and see if the Dixie II+ has the same backplane connectivity that the Dixie II has (see that module's listing for an explanation). If so, then I'd suggest running the Dixie II+ as a 'master VCO' for a Dixie II, sort of like the Moog 901 driver/oscillator arrangemen except that both can output signal since both are proper VCOs.

Thought I'd toss this out on here in case anyone else has run into this in the new version of Live, and might have some tips beyond doing a reset (done that, didn't help).

I was working on a very long (65+ minutes) work involving a lot of timestretching and DSP work. I had four stereo tracks down and collected/saved, then started in on a fifth. While working with a VST plugin (forget which one, might've been Waterfall) the entire system went into this fatal internal feedback loop, building into a deafening screech that forced me to cut the monitor amp. Then when trying to regain control, nothing was responsive...I eventually opted to quit at Win10's crash prompt, then restart the track from the last save point. But when I tried that, Live was no longer capable of loading. It now hangs at the very beginning of startup, as if whatever happened wrecked the install itself!

I put a service ticket in w/ Ableton support, still waiting to see if they can sort this out. But has anyone else on here run into a crash under Live 10.0.1 of this magnitude? Inquiring minds want to know...mainly, so inquiring minds can get the damned thing fixed so inquiring minds can get the hell back to work! Aaaaaaaagh!

Tiny but cool...I'd go with a regular passive mult, though; you don't have enough voltage splitting in here for it, and you can save a little chunk of cash that way.

Definitely post some noisemaking examples with this thing...it looks properly 'abusable'!

Starting point #1: https://www.sweetwater.com/c644--Drum_Triggers_and_Pads

That's pretty much everything you can commonly get in the marketplace these days when it comes to electronic drum pads, sensors, and the like. The other starting point would be to pull up the 'Drum' listings on here (preferably in Eurorack, which has the most options) and look for modules which feature a drum-trigger input OR modules which can translate a drum trigger into a synth gate/trigger output. Attach part 1 to slot 2, finish the synth build, pull out a pair of sticks and go nuts.

(FYI, the Markdown formatting bollixed the URL above. Insert a _ in between Drum and Triggers, and between Triggers and and, then maybe lose the italics, and you're golden.)

EDITED Mar 10th 2018, 00:09

Have a look at this article I posted, which goes into considerable depth on building up a full system:

https://www.modulargrid.net/e/forum/posts/index/2868

That's pretty extensive and a long read, but it goes into a lot of detail about the whats and whys of doing a modular synth build. As for the above, I don't quite think that's going to be workable, as it's missing a lot of what should be there and has a lot of things that either don't need to be there, or that're missing the things they need to work properly.

Thus far, it's OK...basic monosynth sort of setup with a LPG down at the end. A couple of things come to mind, tho; first, consider a second VCO. The Morgasmatron is set up for dual inputs and while it also has dual outputs, it also has its MIX out, so you can feed two VCOs in with some waveform differences and have a little more timbral variation. You can also double them up via sync and get weird harmonic sweeps, put them in different octaves for octave doubling, or just double them in the same octave with a little offtuning for a really big sound...this last one works well on basses.

The other thing is that you might consider a second envelope. The Function will be great for controlling one of the LPGs, but you have two of them, which means you could just as easily have different envelopes for each channel the Optomix is mixing down. Also, another major use for second envelope generators, seen all over the place on loads of monosynths thru history, is to have a separate control envelope for the VCF. But seeing as how the Morgasmatron is two filters in a weird cross-relationship, the ultimate number of EGs you might want is actually four. And that's easily fixed by yanking the Function and switching to something like an Intellijel Quadra. Very easy change there.

With the Yarns in place, you're set for expansion as well. Once you get the basics sorted, that's one to keep for building up a larger rig. But it comes to mind that if you're thinking about that acid sound, the sequencer also matters quite a bit, since the glide function of the TB-303 was part of the weird pitch+filter sweep sound. So, why not kill two birds with one stone here; have a look at the Arturia Minibrute 2s and then conjoin that with a 6U Rackbrute, which comes with power, and is very cost-effective plus offers lots of expansion space. Plus, the patchable Minibrute 2s architecture means you can also insert its individual circuits into the modular setup via its patchbay...and nowhere in all of this are you really getting in so deep in modular synthesis that you'll find yourself out of your depth.

Well, the history of analog computing sort of dead-ends around 1968, when digital computing became more common and available. It was actually in the 1980s when mathematicians were forced to rediscover this hardware, because they found that in studying and calculating chaotic processes, a digital computer with discrete logical steps wasn't able to sufficiently parse some of these new mathematical topologies. But by that point, a lot of the machines had been consigned to the scrap heap (which is where I found the Systron-Donners) as 'obsolete', and the tooling necessary to produce these on a factory scale again just wasn't available; in fact, many of the firms making them were long-gone. It's sort of like what was happening to modular synths in the early 1980s, when everyone jumped to digital in the rush to something 'better'...although synthesists rediscovered modular synthesizers in time to keep the whole thing from totally dying out, whereas analog computers had long been considered worthless, obsolete dinosaurs in computer science by the time they were pressed back into service again. That's the difference between 'art' and 'science'; sometimes the cutting edge ISN'T what you want/need!

Sure, you can chain as many mixers as is needed to create a suitable composite signal, and that trick works for either audio or CVs. Just don't make the mistake of trying to sum the outputs via a multiple, because that would be about when you'd discover that your outputs didn't have reverse protection (resulting in a rather expensive POP!)! Also, you can't exactly use a mixer to sum gates and/or triggers; this is best done with some module that doesn't have a possibility of attenuation, such as a Diode OR or something similar.

EDITED Mar 9th 2018, 03:07

No, not tube, but one of the first transistorized analog computers. But since it comes from that switchover period, it still uses the older +/- 100v standard that was typical up until that general time. It was right around then when the first +/- 10v machines began to appear, but this certainly isn't one of those. As for it looking like a modular, that's because these were the sort of things the modular synth was modeled after; Don Buchla certainly had experience with them as a researcher with NASA, and I suspect Bob Moog saw a few while in his academic studies, pre-synth.

As for the Comdyna GP-6, that's really about the last analog computer that was being made, right up to around 2000 or thereabouts. Comdyna had another machine that they'd specially specced out for music work, though, although I'm not sure if any of them sold. I forget the model number of that one, tho. After they went out of business (so it seems), I don't think anyone is currently making analog computers anymore. And that's kind of...irritating, actually, because they do have more uses than in just an academic/research setting, but one has to actually know how to program one to get any use out of it and that's a bit of a lost art, it seems. In theory, though, something like one might be cobbled together from discrete synth modules, but the thing that makes the Systron-Donner useful is that it's patched more like a Serge, with stackable banana plugs, which opens some not-exactly-computational behavior up for (ab)use.

Should be easy enough; Perfect Circuit has them listed as 'arriving soon', and they're pretty reliable as to that 'soon' being accurate. For $189, getting that many functions is pretty amazing...it's worth the wait.

The analog computers I have are Systron-Donner 3300s...they were intended as a teaching machine, to demonstrate the principles of analog computing in a student lab situation. And like a lot of earlier analog computers, especially the very ancient vacuum tube ones, they operate in a +/- 100 volt scheme. It wasn't until near the end of the widespread use of these machines that +/- 10 volts was finally implemented, but one of the last makers of these machines, Comdyna, even marketed an analog computer (about 15-20 years ago) designed for synthesizer applications. Damn shame it came out when it did, because back then Dieter Doepfer had just began the whole Eurorack thing, Roger Arrick was just getting the Dotcom thing going, and so on. Had Comdyna lasted until the present, they'd likely be selling those units at a nice pace!

But because the Systron-Donners I have use the higher voltages, I'm going to have them modified with some 3.5mm outputs that also have hardwired attenuation to pull the voltage down to the more useful +/- 10v, and I might also have some attenuators added to allow me to scale that down even further as needed. It's also going to be necessary to add some circuitry that will allow some common LFO-type behavior, such as CV control over the clocking, a reset gate input, and the like. But the idea is to keep the internal hardware fairly original, which means those removable program panels will have big red letters at the top to remind me "DO NOT PATCH OUT! 100 VOLTS!" so that I don't make some random, dumbass mistake and patch from that to something that can't handle it.

There are larger (MUCH larger) systems out there, but when you start looking at their power draws, you realize pretty quickly that they won't work nicely being just plugged into yr.basic wall outlet. And ten opamps isn't too shabby...considering that you can patch these up in a massive amount of possible configurations, and control/balance them all sorts of ways. The closest parallel I can think of would be if you had several Maths, but they were bristling with patchpoints that allowed you to totally reconfigure every sort of parameter's signal path. That's actually the big difference here; you simply can't have that level of configurability in Eurorack without the control panel looking like Swiss cheese from all of the jacks, and even if you did, it would create such a level of confusion in users that they'd likely give up on synths altogether and take up the ocarina or some such.

Well, if you've got 4 hp and you want maximum bang-for-the-buck, consider a Expert Sleepers Disting...DSP-based, multiple uses, basically, it's a very small Swiss Army Knife of capabilities in not a lot of space.

https://www.modulargrid.net/e/expert-sleepers-disting-mk4