Interfacing Max and Your Eurorack: Expert Sleepers

    As I mentioned at the conclusion of my LFO tutorial series, I’m starting work on a set of tutorial articles that focus on using Max alongside Eurorack modular systems. Along the way, I’ve been talking with friends and acquaintances in the Max user community, many of whom are using the ability of their interfaces to output DC-coupled voltages as a way of sending control information to their analog racks - I’ll be talking about this in the first of the analog synth tutorials, so stay tuned. I have been a little surprised to discover that a number of my friends aren’t well acquainted with what seems to me to be the simplest solution out there: The Expert Sleepers interface modules (and plug-ins). Since we customarily spend the first week of the month looking at hardware in the newsletter, I thought I’d give you a quick rundown on something that’s pretty straight-ahead and streamlined and works for me: a pair of Expert Sleepers Eurorack modules and a nifty little interface.
    For output to my rack, I picked up an Expert Sleepers ES-3 module, which gives me 8 separate CV outputs via ADAT Lightpipe.
    One of the reasons for going with the Expert Sleeper modules is that I want something that my DC-coupled output on my interface won’t give me – bidirectional connections. For that, I added an ES-6 module – it’s the counterpart of the ES-3, providing 6 inputs to my computer via a second ADAT cable. Yes, you read that right – 6 inputs rather than 8. If you’ve gotta have those extra two channels, you’ll need to add an ES-7 module as an expansion. I don’t really need the extra channels. Yet.
    In case you’re wondering about clock signals and synchronization, The ES-6 derives its clock signals by virtue of being cabled to the ES-3. The ES-3, in turn, derives its clock signals from its lightpipe input. You connect the cable that comes with the ES-6 up when you install it in the rack, and that’s it. You’re off to the races.
    When it comes to a lightpipe (ADAT/Toslink) interface, you may already have what you need if your audio interface is equipped with lightpipe input/output. My older MOTU Ultralite interface doesn’t, so I decided to go with a smaller and lighter solution – a USBStreamer B MiniDSP interface. It’s a straight-ahead piece of kit: a USB input and an input/output pair – one for the ES-3 and one for the ES-6.
    Your mileage may vary on this input choice - since I’m often monitoring the analog synth output straight into the board in the studio anyway, I didn’t really need audio from the interface. Another solution would be to go with the Expert Sleepers ES-4 SPDIF/CV interface for output combined with ES-7 expansion modules to provide CV input pairs.
    If you’re using it on a Mac, the miniDSP interface is easy-peasy-lemon-squeezy in terms of setup: Plug it in, watch the white LED next to the USB connector light up, fire Max up, drop a [dac~ 1 2 3 4 5 6 7 8] and/or an [adc~ 1 2 3 4 5 6] object into your patch, double-click to bring up the Audio Status, select USBStreamer as the output/input source, and start patching.
    If you’re using a Windows system, there’s an ASIO driver available from the manufacturer. When I ordered mine, they helpfully included the necessary download information as part of my order.
    The tutorials I’m working on are all about rolling your own when it comes to things to do with input and output, but I’d be remiss if I didn’t mention that the Expert Sleepers also offer their own solution for software control: their collection of Silent Way plug-ins. They’re a de facto standard for Live users, but Max users can also benefit from hosting the plug-ins (AU or VST) via the vst~ object.
    In total, there are 18 or so Silent Way plug-ins, some of which are intended to support specific Expert Sleepers modules (e.g. The AC Encoder works alongside the ES-1 module and removes the need for a DC coupled audio interface), and some of which produce control voltages you can use with your rig. You'll find a great in-depth description and look at the set of modules here. It's a great collection of tools, and an interesting thought experiement for the Max programmer - you could begin to imagine Eurorack control possibilities by taking a look around and asking yourself what's not there from your point of view!
    I'll have more to say about all this later, so stay tuned - and happy patching!

    • Jan 06 2016 | 5:24 pm
      Hi, I'm using the ES3/ES6 combo with a USBStreamer as my main audio interface - really happy with this setup, has been absolutely reliable and the DC in-out is wonderful.
      One thing worth mentioning is that, because the USBStreamer is class-compliant, this can be fully used as audio interface for iOS devices via the Camera-Connection-Kit.
    • Jan 06 2016 | 5:31 pm
      Yes! This series is already a favourite :) I have a small eurorack building up, and i'm using a borrowed, even older ultra-lite to send CV for now. Didn't even cross my mind you can buy a external piece of gear to have that ADAT connection. Will have to give Silent Way hardware a second look.
    • Jan 06 2016 | 6:25 pm
      Can´t wait for your tutorials, i have an ES-40/ESX-8CV Combo and love it, so curious what you´re coming up with! :) your tutorials ight also be a good reason to finally buy the ES-7.
    • Jan 06 2016 | 6:28 pm
      Just spent a small fortune on modules over Christmas including the ES-3/ES-6 combo. Right on time! Awesome stuff here.
    • Jan 06 2016 | 7:48 pm
      Ha! Gregory, that's a great tip. I did try to use my (otherwise wonderful) RME for this and got some amazing, but unwanted portamentos as the "DC" voltage slid back to 0. BMB con. is using a eurorack often at the moment, so I think we need to get one of these dingetjes.
      groet, Justin.
    • Jan 06 2016 | 8:14 pm
      Yes, great info, i have been using this combo (ES-3 & ES-6) plus ES-5 (which is fantastic to send clock signals and guess what !!, OS Expert Sleepers brain, has created a Max external for it). Max works perfectly with Eurorack synths, the only thing you have to care about is 1/volt per octave calibration, specially if you want to send CV to control pitch. Recently i added this combo to my Buchla 200e with a Eurorack Blade adaptor and i'm having incredible results.
      Cross modulation between Max and my Modular Synths was a dream now is real.
      Don't forget to look at ES website and download the Max externals for its modules. Looking forward for more on this
    • Jan 07 2016 | 12:43 am
      Thanks for the great article! The USBStreamer is a nice find for this.
      I second lesespejo's recommendation of Os's Max objects - I've got some great results using these and ESX-8GT and ESX-8CV modules to get ridiculous numbers of CV channels.
      I got annoyed about the ES-6 only providing 6 inputs, so I combined an ES-6 and an ES-7 to make an ES-67 module! (I did actually need 8 ins, it wasn't just an OCD thing..) - images attached
    • Jan 07 2016 | 12:50 am
      (sorry for duplicate images, don't seem to be able to remove)
    • Jan 07 2016 | 8:14 pm
      Thanks for the helpful info. Can you go deeper into topics like output voltage ranges e.g. for driving Buchla systems (1.2V/Octave, CVs up to 13V) and give some info about latency?
    • Jan 08 2016 | 9:41 am
      This was a great read. Thank you for posting. I would like to know more about the ac encoder vs dc-coupled. if i can make some cables and use my current audio interface what would be the difference?
    • Jan 08 2016 | 5:36 pm
      Martin Beck,
      ES-3 outputs +-10 volts maximum, so it's not good for working with pitched CV (if you want to control an Oscillator's pitch with it, i really recommend using an extra module, synovatron CVGT1 Another important thing when working with Buchla 200e is to consider that this Synth wants only + voltages, and that is a really easy thing to do with Max, so if you want to send an LFO you have to some basic maths to send only a positive voltage. I've been a long time working with this combo and i can say that a voltage from 0 to +1 with sig~ gives me a complete modulation of for more info about it take a look at this thread at Muff's (best forum in the hold world ;-) sorry for that)
      Of course all this is valid for Buchla 200e
    • Jun 27 2016 | 8:44 pm
      a question please, I have just checked my new ES-6 module which is connected to my RME FF400 interface. On the attached pictures you see input values... ADAT 1 is connected to a 4MS PEG and the ADAT 2-6 ports are not connected to any Eurorack module.
      It looks like the ES-6 and all ADAT ports works fine but is it okay, that the unconnected ports shows signal values... -30 to -45?
      Do you have the same signal input levels?
      Cheers Simon
    • Jun 27 2016 | 10:08 pm
      Here I have found answers:
      "Issue with ES-3 mkII / ES-6 / TotalMix..."
      Cheers Simon
    • Nov 08 2016 | 1:29 pm
      Hi there,
      I'm about to build a new set up integrating CV and MAX, so found this post reaaaally useful. Thanks a lot few questions:
      does anyone has ever used the ADDACOO1 VCC? it looks like doing the right thing we need here, plus virtually lot more..
      Also, I noticed that ES just released their ES-8 wich does not require ADAT in (but it's quite more expensive)
      thanks for your comments best