Yeah, it’s a hefty expense, but in addition to being the only interface I’m aware of with multiple DC-coupled inputs, it’s pretty incredibly feature-packed; a really good general interface, has balanced line out, a ton of inputs and outputs, incredible extensibility with the GT and CV expanders, and it’s an extremely capable digital crosspoint mixer which can work when not USB-connected. So in addition to its USP you’re getting a TON of bang for your buck.
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There’s an ADAT DC-coupled I/O interface too.
NOTE: only outputs are DC-coupled
I’m still playing with microcontrollers and OSC - easy to find a microcontroller with DAC and ADC with plenty of resolution. solder to some opamps, and you can have DC i/o for not that much money. And all the channels you want (and the throughput of OSC on USB permits)
Plenty of opensource schematics and whatnot explaining the electronics (electrosmith daisy platform, Mutable instruments, 16n etc.).
Haven’t measured throughput or anything - but it’s something to consider (if you DIY electronics). I don’t know of any commercial offerings of OSC CV I/O.
The sample rate of trowaSoft cvOSCcv is low (100 Hz), but easy to change in the sourcecode. I tested 1000 updates/s - works fine with 16 channels of float.
8 channels of float over OSC:
It does polyphonic cables too - transfer 16 CVs on one OSC address.
1ms OSC interval (#define TROWA_OSCCV_DEFAULT_SEND_HZ 1000):
Common MCU dev boards are capable of 12 Mbit/s USB transfer. divided by 1152 bits per one 16 channel OSC message gives a max rate of 10.416 16 ch OSC messages/s. Bits are added for transfer on the USB serial. I have not measured the real maximum for OSC<->MCU.
USB - Wikipedia
GitHub - CNMAT/OSC: OSC: Arduino and Teensy implementation of OSC encoding
Serial Line Internet Protocol - Wikipedia
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Good point (and Os from Expert Sleepers also makes the ES-3 and ES-6, which together ~= a Optx). I was thinking of standalone interfaces, but if you’re already up and running with an interface that has ADAT connectivity, these are good options.
Additionally, the Expert Sleepers ES-7 can go on to an ES-40 and give you DC-coupled input over coax S/PDIF, but just two channels’ worth.
I have one and use it with Bitwig and VCV in Ubuntu… If you can’t find a one then email expert sleepers where in the world you are, they will probably advise when and who will be getting stock.
The used market for Expert Sleepers appears as people upgrade to new offerings! I’ve been super-skint and finally bought a used FH-1 when FH-2 was released and an ES-3 when ES-8 was released. Everybody’s been pressing Os to make direct USB interfaces since the beginning, so demand for these is strong and sometimes deals can be found for the earlier ones.
My latest box is my first one without Firewire, so my MOTU>ES-3 setup is finally getting outdated. Thinking of trying to make Lightning and USB-C to ADAT converter myself from a Teensy but I’m over my head. The effort will keep me busy until I can both afford and find an ES-8 and/or ES-9.
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I was looking into this one and I read on Modwigglers that while the outputs are DC Coupled, the inputs are not.
I believe the original intention was that both would be DC Coupled but iirc they ran into supply issues or something like that and had to ditch the DC Coupling on the inputs in order to get the module released.
It may be that the DC coupling on inputs is added in a later version.
Just something to bear in mind if you want to run CV from hardware into Rack - which you may well want to do to take advantage of Rack’s scopes etc if nothing else.
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Thank you for pointing that out.
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Important clarification, thanks! Yes, it’s just the ES-9s that don’t go down at the moment. The older stuff is still in good supply and even new it’s often marked down significantly. I’m looking into an ES-7/ES-40/expanders configuration (since it could work with the ES-9 via opto/coax conversion, or with other interfaces) and seeing some very nice prices on those.
Oh no! That’s a big downside in modern hybrid systems. Thanks for noting. If anyone wanted ADAT input the Expert Sleepers ES-6(/ES-7 for two more inputs) is definitely DC-coupled.
Is there something as good as ES-9 for half the cost? $650 seems like a lot of money for what it is no? I mean audio interfaces aren’t that expensvie these days are they?
es-9 isn’t just an audio interface, it can also act as a mixer with external level control. I don’t think that adds enough to justify the price, but I personally am happy enough with mine that I’m glad I made the investment.
the dc coupling is amazing, though, and while I haven’t found software that manages to use every feature, I’ve written enough that it’s getting close to using every feature (still waiting for my midi expansion for it, at which point I’ll build some midi-translation hardware and control its internal mixer with my launch control xl)
If you really don’t need all the ES-9 features or ins/outs then as mentioned above I’d recommend hitting up Reverb or similar secondhand sites for used ES-3 and ES-6 modules. Did that recently and got both for £240 combined, less than half what ES-9s are going for and that got me 6 ins and 8 outs via two ADAT ports.
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What main tenant said.
The ES-9 is a great interface and good for a portable system but In some ways it is not the most flexible solution for studio use. What if you want a Mic input to record some vocals? What if you need more than 8 CV outs? (I know it has more than 8 outs but only 8 are really usable for sending signals to modular hardware).
There are other more flexible solutions - interfaces with lots of ADAT in/outs like the RME digiface, and the ES-3/6 combo will work well with those. You can then add more ES-3/6 if you want and/or an AD/DA converter like the Behringer ADA8200 for Mic and line inputs from other synths etc.
I think some of the Presonus interfaces have DC coupled sockets, check the specs.
Expert sleepers dedicated support and regular feature updates openly discussed on modwiggler is worth considering.
Hi, I use the ES-9 with my setup which consists of a full 2 racks of AE Modular, a MOOG DFAM and Subharmonicon, VCV Rack, and Bitwig Studio. I also use a Beatstep Pro and a AKAI MPK225. My laptop runs Linux/Kubuntu/UbuntuStudio and uses the Jack Audio system. I can route everything to everything using this setup.
The ES-9 is great because I can send CV to and from my modular/semi-modular stuff and my DAW and VCV Rack. I don’t experience any noticable latency. It was hard to figure out how to configure the ins and outs on the ES-9 at first, but after a little reading and experimentation I got it working the way I wanted it to.
I also use it some with Windows 11 and Ableton Live 10 and Bitwig Studio as well as VCV Rack, with the same great results, though it needs a driver for Windows.
I had a real hard time locating one to buy at the beginning of January. I live in Colorado and the only place I could find one was Blickin Synths in the UK. But he shipped it via DHL and it got to me in less than 72 hours.
I’m really happy with mine.
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You don’t have to change the source code… just send a 1kHz (or whatever frequency you want) oscillator into the TRIG input.
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Hello, I have been looking into buying the ES-9 as well. But I was put off by people complaining about it’s latency. So I went for PreSonus studio 1824c which has DC-coupled outputs. It doesn’t have any noticeable lag providing control voltages - only they aren’t the same values as shown by the outputs in VCV Rack 2 Pro. Are there any settings I need to adjust so the outputs of the audio interface match those in VCV Rack, or can this only be achieved with dedicated MIDI-to-CV interfaces?
Thanks for your help!
Cheers,
Dirk
18 dBu max output according to tech sheet, equals 8.7V peak. (I used this converson tool)
10V CV on the VCV audio module outputs sets “all bits to high” and gives +8.7V on the interface. Use a multimeter if you need to know the exact value - and a DC amplifier/multiplier (A*B+C) like Befaco A*B+C if you need to scale it to +/-10V.
The midi-to.CV interfaces often output full eurorack range -10 to 10 V, some do -3 to +7V, some only 7 bit resolution, some 14bit.
The Expert Sleepers ES-9 and ES-3(I have one of these) are DC coupled audio cards, that have calibrated (not) -10 to +10V outputs.
You can use a module like VCV Library - Bark Clamp or VCV Library - Befaco A*B+C etc. to do the conversion.
Thunator might come in handy also.
That’s fast, precise and complete guide - many thanks! I did compare voltages of gate on/off and pitch coming from 1. Arturia Keystep 37’s CV outputs and 2. One of the audio interface. Pitch was way off by both an offset and then scaled. With the tools you linked I should be able to tweak until the voltages match. I wonder if the Expert Sleepers really have so much lag or if the cases I came across were user errors or due to older firmware or bad settings. And I wonder how the Polyend - Poly 2 compare regarding latency.
Btw, I love Denmark 
The lag/latency depends of the buffer settings in the OS - like any other audio I/O device. this is true for the Expert Sleeper cards ES-9/ ES-3 at least (2ms - 30 ms latency depending on various settings).
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