Ambient / Atmospheric Rack Feedback

Hi everyone,

I just made the jump into eurorack and I'm looking to create atmospheric and ambient music: long, slowly evolving sounds with interesting percussive textures that gradually emerge and dissappear. I'll be sending data to the system with a Digitakt, hence the uMidi. My case is a synthrotek 84hp 6U +1U.

I'm curious what others think about the setup. Am I missing anything essential? Are there redundancies that I should address? Your help is much appreciated. A brief rationale for each module is below.

Thank you for your time!

Model D - an easy way to get a complete synth voice. I plan to use it for drones and patch other sources through its filter for interesting effects. The ext audio in is also cool.

Lo Fi - I'm looking for warbles and a way to treat big atmospheric freeze effects with a cassette tape hue

Magneto - great way to create complex delays with simple melodic and/or percussive sequences

Clouds - useful for ambient work, freeze effects, and more

Ripples - I need a filter beyond the model D. This seems nice.

Quad VCA - You can never have too many VCAs. This one seems useful for controlling all sorts of modulations with the effects.

2hp Euclidean - cool rythmic tool for controlling effect parameters on Magneto, Lo-Fi, and maybe clouds?

4ms Clock Divider - cool way to use Plaits as a percussion tool and get different kinds of sounds, all in sync. Shift function is also a plus.

Plaits - This seems like a great VCO: versatile, melodic, percussive. I want another VCO beyond the D's in order to create paraphonic sequences that slowly appear and disappear.

1U Stuff: Umidi conversion to process data from the digitakt, buff multi, mixers, master headphone out, etc.

EDITED Mar 29th 2018, 01:35

Hate to break it to you, but the Intellijel tiles will not fit in a Synthrotek 1U row. You have to go either with an Intellijel cab, and then use only the Intellijel tiles, or go with the 'normal' tile format, which opens up a lot more options but won't allow for the Intellijels. Also, unless you have a Clouds or know you can definitely source one on the used market, you'll have to use a third-party build of that module, since Mutable discontinued in in the last couple of months.

Next up: the RCD requires a clock. While there's things here that might double as one, you're not guaranteed that the RCD will properly 'read' them to derive its divisions. You'll definitely want a proper clock outputting proper trigger pulses to make sure that modules like that work 100% properly.

Definitely some problems here...you might consider stepping back to square one given that the case issue poses a significant stumbling-block to the tile row, and since some of that is critical to the overall function, much of that needs rethinking. Also, consider keeping the Model D in its own case; you'll be glad to have the extra space for modules later on, and it'll work just fine with the modular setup whether it's in the Eurorack cab or not.

Thanks for the feedback, Lugia. I might have to get a 3u uMidi in place of the tile option. I was planning to use the clock out from the uMidi to send to the RCD (and other places), but you're not thinking that's a good idea? Are there alternatives that you might recommend?

As for the tile row, I'll probably see if I can get Pulp Logic pieces or other makers that do fit into the synthrotek cases.

I figured it would be wise to keep the Model D in its own case, but I liked the idea of having everything all together. The Synthrotek case has a cool splash-proof top, and I was hoping to take it to a show and load in in a single trip. I guess that's not entirely possible now, but with the new space it opens up, I'm curious if there are any essential pieces that I'm missing here.

Again, any and all help is much appreicated.

The uZeus supplies 2000mA on the 12V rail and 500mA on the -12V rail, and your system pulls 1735mA on the 12V rail and 466mA on the -12V rail.

It's technically "within specification", but you're really pushing it. You want to be under 80% of the rating of the power supply because sometimes modules may pull more power than is actually specified (especially when turning the system on). You'll either have to sacrifice a module or get an additional power supply that doesn't take up space in the rack.

I'll leave critique on your module selection to somebody that's into ambient/drone type stuff.

Should still be possible to do a load-in in one shot...look into some cases/bags that'll allow all of the gear to be in one package. In theory, you're still in a size range that would still work as a carry-on, if we're talking a Digitakt, Model D, modular, and a mixer and laptop. The whole mess should more or less fit something in that size, depending on what you find and how creative you get with it. A good friend and colleague of mine gigs with about the same amount of gear (perhaps a little more, actually) and he's still able to fit the whole live rig into a carry-on.

Also, do pay attention to m1sterlurk's notes about the current draw above. That Model D alone draws a full amp on the +12 V rail...and the same span of panel (70 hp), with typical modules, really shouldn't draw much more than a couple hundred mA, at the very worst. Yet another reason for leaving the Model D in its own cab, I think. My rule of thumb says that as long as I can keep the current draw below 2/3rds of the maximum rating for the power supply, I'm pretty much assured that no operational state (such as power-ups, which can sometimes be more than the operating current load for tiny intervals) can jump beyond the supply's rated capacity.

Clocking...hm...there's several ways to do that. First method would be what you'd suspected: using the MIDI interface's clock out and clocking everything off of either a laptop or the Digitakt. Annoying that the Digitakt doesn't have a dedicated clock out, tho. Method #2 would be to clock everything from something a little...different. Have a look at Expert Sleepers' FH-1. Now, that would allow hosting of the Digitakt directly to/from the modular, and it can do the same thing for anything else that requires a MIDI host. It's much more complex than a regular MIDI interface as well, allowing a lot of user-definable functions to be implemented along with the MIDI conversion. DO, however, power the Digitakt via its own adapter; while the FH-1 can technically supply power via USB, you don't want to be right back in the same mess as having the Model-D in there with respect to current draw.

As for the tiles: good move. There's a lot of stuff in 1U out there from several makers that won't/can't fit in an Intellijel case, and sticking with the 'normal' tile format seems wiser. And yes, that includes a nice audio interface from Pulplogic, plus gobs of other toys.

Now for the modules themselves. I advise you to think small. ANYTHING that can be reduced in size should be if we're talking about a small travelling rig like this. Take stock of the functions you already have there (excepting the Model D, of course) and see just how small you can go with the same/similar/better functions. Take the Magneto, for example. Awesome delay. Frickin' huge, though...great for a large-scale rig, a real space-hog in this. But...consider what you'd get if you used a Chronoblob, and then used that delay's insert point to drop a few little 2hp processors into the delay feedback circuit. Quite entertaining...and smaller, too. Or the Quad VCA, which is good, but the 1U tile row lets you add a couple more VCAs, potentially for controlling mixer output dynamics, ergo no need for a second one (and VCAs for CVs can be very useful things! consider mixing a bunch of CVs, then controlling their summed level via a VCA at the Mix-A's output...nuts!).

Last thing: effects in a modular that can also be done by a stompbox should probably be done with a stompbox to save space. But this doesn't mean you have to be conventional about that, either. F'rinstance...the Zvex module could be replaced with two other I/O modules for send/return work to outboard FX boxes, one of which could be the selfsame box, or even a better/crazier lo-fi looper. And by replacing that with typical I/Os, which tend to be 4 hp, you get back 2 hp to use for something else (like half of yet another FX I/O, maybe?). And given that stompboxes are small things, they're easily jammed into the aforementioned gig bag with everything else.

Anyway, that should give you a bit to think about for a hot minute or two...

Do your russian escorts dress up as bananas and tell fairy tales? I'm totally into that.

The right time I will ever have that won't stop? Gee...I hardly think you could make that work. After all, Robert Fripp has to change the tape reels on his Revoxes eventually, plus he's going to get really tired of playing that Les Paul of his for weeks on end.

whoa, that spam post got weird really fast...

First, enormous thanks, Lugia, for the thoughtful response. I agree that using the Model D on its own would be the best bet. Unfortunately (but also kinda fortunately), I was lucky enough to pick up some pieces to start assembling my set up, and they were the ones you recommended I rethink. So far I've got the synthrotek case, a lo-fi, and a magneto. I've got a microbrute that will allow me to use the effects, but I'd like to expand the rack to contain full synth voices and effects that I can control via a midi sequencer. Eventually, my goal is to expand into something capable of more complex and generative patches. Thanks, too, to m1sterlurk, for the input on the power supply. I think keeping the Model D on it's own will allow me to stay in the safe zone of 80% consumption.

Remember that your system as currently configured is also over the 80% safe zone on the -12V rail, though if you were to swap out the uZeus with a 4ms Row Power 40 you'd be well in the safe zone.

Also I had to have fun with the spam poster...I really can't help myself.

Yuppers...ALL rails need to be inside whatever safety window you choose, not just the +12 or whatever. The triple-output supplies used in Eurorack aren't capable of pulling the 'extra' from another rail that's not being used. Treat a Eurorack supply as three discrete supplies, and it makes more sense. In fact, some large-scale builders will actually use just that: three separate supplies dedicated to each rail, each one massively overspecced for the current draws found in really large systems.

OK, back to modules...we've got 7U x 84 to play with here, and the Magneto and Lo-Fi are 'givens'. Lemme screw around with this for a hot minute...

Easy-peasy. Now, this thing is set up for two discrete voices, both with the same general signal chain: Plaits + Doepfer A-111-3, so two VCOs per voice. The Quad VCA allows you to mix/amplitude control them by splitting the module by outputting from Out 2 and Out 4. Waveshaper and ring mod after that, then two Ripples to match the VCO compliment with identical VCFs. Then we have a 3xVCA and a 3xMIA for various expanded mixing/control methods. The 3xMIA also can serve as an inverter, offset source, and so on.

Next row. I put in the FH-1 I'd mentioned before as a USB host module for the Digitakt, but it can also work with other devices needing a USB host, or a computer with an adapter that allows that to connect to the FH-1. Also from Expert Sleepers is the Disting mk4, a fantastic Swiss Army Knife device, great in a small build for multifunctions. The little blue thing is a Zlob module that contains a noise source as well as the always-useful sample and hold. Then modulation sources: Batumi (4 LFOs in 10 hp) and a Quadra (4 AD or AR envelopes with looping). You know the next two, of course, and then a Mixup for a stereo out (to make proper use of the Magneto's stereo capabilities). And, oh yeah...the Row Power 40, which gives you 300 mA of extra current headroom on the +12v rail and 250 mA on the -12. A little tight for my tastes, but quite within m1sterlurk's suggested current tolerances.

The tile row is where I got artful, tho...first up is an insert module, like I'd talked about above for putting a stompbox into the signal chain, but it can also be used as an external preamp for outside signals. Then there's the neat stuff. You'll note the mixer tiles, first up...CV on left, audio on right. Now, beside those I placed the appropriate VCA, then FSRs, and last, an AR envelope.

How that works is that it gives you a force-sensor-controlled VCA for a group of summed control voltages on the left, and for the same in audio signals on the right. BUT WAIT! There's MORE...since the FSRs also output a gate, I added the AR envelopes so that you can also trigger those from the FSR's gate to send elsewhere...or even to the VCAs along with the FSRs, since the VCA tiles have dual CV inputs. This gives you an interesting control option that wasn't there before, but there was very much a hint at in the original build, and it also provides a tactile percussion interface, since you can also use the FSR/VCA/AR combo with a very short envelope and some noise, etc to tap out little noise-burst percussion bits.

And of course, your stereo output tile pair closes it out. Lots of possible patch-in for the Model-D here, plays nice with the Digitakt, and loads of sound potential in an itsy-bitsy cab. Works?

EDITED Mar 30th 2018, 22:15

WUT!? This is enormously helpful! I'm going to need a while to digest all of this, but the possibilities you've suggested are really exciting. That the model D and Digitakt are so easily incorporated into this rig makes it extra exciting. I'm far from being in a position to purchase all of these modules at once, but I like the idea of getting a single Plaits and A111-3, power supply, usb-midi interface, etc--basically everything for a single voice--and then slowly building it up from there. The Pulp Logic tiles are reasonably priced, too, so incorporating them shouldn't be too bad I forgot to mention earlier, but the case I picked up also included a Mix A and a Mix B (which, I gather, is for mixing audio and CV respectively?)

I also like the incorporation of the Bautumi. I've been eyeing it for a while and I think the long, slowly-morphing sounds that I've got in mind will more easily come to life with a quad LFO. The demos online are really inspiring. Videos for the Disting are also pretty exciting. Tons of functionality in a very small space, for sure.

Lugia, for real, I've spent so many hours watching videos and trying to assemble a rig on my own, but your thoughtful comments have seriously helped to steer me in the right direction. Big thanks again!

Yerwelcome! For me, this is working from experience; having been working with different types of electronic instrumentation for about 40 years now, ranging from cobbled-together breadboards and bits up to drool-worthy modular systems, I'm just real used to how these things should work. But there's a few things I routinely do:

1) Cluster the functions. I always try to get the different module functions in the same general areas. That way, you know where the thing you're looking for in general is going to be, and you can move around and patch very rapidly once the layout's learned...which, again, this clustering makes easy.

2) Follow a model that works. As a rule, my overall layouts follow a distinct order of function placement, which is actually based on a still-coveted classic that I've used off and on since 1980: the ARP 2600. When you get a chance, have a look at one, then compare this build to that. The ARP 2600 is such a desirable synth because not only does it sound great, it has an easily-navigable layout. You know where the VCOs are (upper left), the filter is (dead-center), and the VCA and reverb is (right end), with various modifying things on the lower tier of submodules. I recall a quote in Mark Vail's 'Vintage Synthesizers' book: "It's the only synth I can play when I'm drunk."...and there's very good reasons for that! Also, I find it a bit telling that two companies that built huge modular systems (namely, Moog and ARP) first then wound up going with much the same layout in their first portables (Minimoog and 2600, respectively): VCO->VCF->VCA, left to right, and control placed convenient to all of these.

3) Build to scale. These days, it's possible to get teensy modules with massive functions, and they're great when you're building in a tight space. On the other hand, if you're doing a big studio rig, go big with the modules. But make sure your form factors always fit the cab they're being chosen for. You want as much function as you can jam into the space you've specced out.

It also helps, probably, that ambient is what I've concentrated on musically in one way or another since the early 1980s. So I have a good idea of what'll function properly for that, and can choose accordingly.

As for the mixers in the tile row: yep, you got it. The Mix-A is DC-coupled, and a linear DC-coupled VCA is next to it. But the Mix-B is AC-coupled, and needed an exponential, AC-coupled VCA for its audio-only path. But that being said, you can easily use the two different VCAs as percussive amplitude control for differently-weighted noise types off of that Zlob module, with the linear one giving you a softer transient response and the exponential being perfect for hard, fast 'snaps'. And then, you just play the FSR's like teensy-weensy bongos!