Hello World, and Ihor. =)
So i bought a Presonus 1824C which is DC-Coupled. Unlike expert sleepers Presonus does not provide any software. The reason for my purchase was to sequence my semimodular from VCV rack and have all my utlities in VCV Rack. Now when i am here i cannot find what module that will communicate with the interface.
On windows, I would want to install an ASIO driver for the interface. You probably allready know, that the interface has DC coupled outputs only. The inputs are AC coupled.
Presonus universal control (download): PreSonus® Studio 1824c | Interfaces
use one VCV Audio-16 for the 16 first input and output ports. use a second VCV Audio-16 for the 16 next input and output ports.
send 10V virtual volts of CV to the VCV Audio “To device” port that you determine corresponds to a line output. Easiest is perhaps to look in the manual for audio stream numbers for each output - therer may be different settings wether the interface onboard mixer is turned on or off - i havent read the docs, only for Presonus Studio 192 that i have.
Use a voltmeter/multimeter to measure the voltage coming out from the interface.
The manual states that the output is “+18 dBU Balanced”. if the calculator i used is right = 17.4 V p-p , or +/- 17.4/2 = +/- 8.7V
Since the output is balanced, and you will be measuring between + and gnd. (not + and -) you will get half of that.
to make 1V virtual give 1V on the output, you need a attenuverter module in front of the audio module. or you can use a formula module to correct for non-linearities yourself.
I did a through measurement of my ES-3 earlier, and shared a google sheet with the result here. Perhaps my calculations are useful for others. ES-3 Calibration - Google Sheets
You can buy ES plugins for VCV to make this calibration easier for you. Voicecontroller outputs virtual CV (-10 to 10V) to an audio module - and gets signal return from the same audio module. VCV Library - Expert Sleepers Voice Controller
Or you can use the mighty and free Thunator. It may or may not work for you. If you oscillators cover the range thunator expects, it will probably work. If they don’t, It will never stop, and exceed the -10 to +10 Voltage range. You will have to watch it, and stop it if it does. There’s an issue opened at NYSTHI’s.
standard “VCV AUDIO 16” module, select the appropriate driver and device (just put vcas or similar to control the levels 
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ok the module makes sense when i look at it =)
I will mustard up the guts to try this, up until now i just played on a semimodular like Marty Mcfly did on his guitar. with my hands. If you dont mind me asking before trying; As you say, 1824C only has 8 dc outputs, so why then “use one VCV Audio-16 for the 16 first input and output ports. use a second VCV Audio-16 for the 16 next input and output ports.”
Yep, you’re right - you don’t use the ADAT channels - the interface has 20 ins and 20 outs. the analog outs on the back panel follow the ASIO audio stream number.
Sorry for the confusion.
20? i see 8 inputs and 8 outputs?
oops, copied the wrong interface specs. that was a Tascam US-20X20
The focusrite has the 8 Analog + 2 spdif + 8 ADAT(Lightpipe) outs.
If you want 8 x full (-10 to +10 Volts) range DC coupled outputs, you can buy an Experts Sleepers ES-3 and connect it to the ADAT output.
I have the Presonus 1824C =)
I’m also using a PreSonus. I suggest you read through this, as it has been carefully written:
I found this video helpful as well:
In short, you should use one of Rack’s callibration modules (I can recommend Expert Sleepers’ Voice Controller, very easy to use) to “tune” your interface. Since mine is USB-powered, the output is very low voltage. So I use an external amplifier module to adjust it to wanted levels. It’s a bit cumbersome, but works.
now I have a Ballrog sitting on my interface. =)
“Since mine is USB-powered, the output is very low voltage.”
That’s not what’s going on. Its a design choice. The manufacturer could have added a DC-DC converter to make +/- 12 V from 5V.
Many models to chose from from other manufacturers too.
I bought the Presonus 1824C, it is what i have now. I cannot switch.
yes the manual on the link seems that i can make it if i follow =) We will see what will happen in the djungle.
Good luck – and be sure to use the proper cable! Cheers and happy new year!
what do you mean with that, proper cable?
I see, thanks for pointing that out! I guess I was confused by this (from the specs page):
Since it is a bus-powered device, the Studio 26c has lower voltage rails than other Studio-series interfaces, resulting in reduced control-voltage range (positive to negative voltage).
Anyway, it’s an awesome interface, I can only recommend it!
You will need an specific type of cable. Just read through the link and watch the video and you will be fine 
Right, i read that before somewhere that ordinary patch cables doesnt work. So I guess it will be presented as you say.
Happy New Year =)
I have a PreSonus Studio 1824c interface that I have been trying to use with DC-Coupling. I can get DC voltage out without issue, but it’s always audible through the interface’s master channels. Does anyone know how to stop DC-Coupling from being heard on the masters? Thanks.