Rack v1.1.6 not responding with Expert Sleepers ES-8 audio driver

Hi. I’m new to Rack. I’m running Windows10 Intel i7 12 core Rack v1.1.6 Connected to Experts Sleepers ES-8 with their ASIO drivers 1: I keep getting “Not Responding”, seem to randomly occur 2: Libraries will not load, also get “Not Responding” I close Rack and the Library loads.

Well first off welcome to the community…

What audio driver version is installed for the ES-8 on your system?

When you say Libraries will not load what do you mean the Plugins on this page:

Or do you mean plugins from the VCV Plugin Library page? https://vcvrack.com/plugins

What web browser are you using?


I don’t have an ES-8 but do have an ES-9, running with Windows.

First off, do you have the latest ASIO driver from Expert Sleepers? I’m using 4.82.0


Then in Rack, I’m using it like this:


I’m also not clear what you mean by Library.

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Seems both have the same drivers, You will find the latest drivers here…


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The latest drivers from Expert Sleeper. Yes Plugins (not libraries ). Browser the latest Chrome.

I’ve tried to install on my Mac Book pro 2015 model running Catalina and I get this.

“Could not open GLFW window. Does your graphics card support OpenGL 2.0 or greater? If so, make sure you have the latest graphics drivers installed.”

The mac had a problem a few months ago, I took it to an official mac dealer and they repaired it (noisy fans) . They backed up my data ( as I did) and they then formatted the disk and installed a new copy of Catalina; Mac was not upgraded to Catalina from a previous OS that is.

Mac runs latest Ableton, Reaktor etc with no problems. My interface box is a FocusRite Scarlet 18i20 2ndGen. I created an Aggregate device with 18i20 and ES-8; all working perfectly fine.

Hold up what OS are you running on? Lets focus and deal with the Windows issue first!

Much confusion here. The website is not loading?? As in the Plugin Library here. The Module Browser in Rack was the screenshot I posted.

You have not mentioned if you have a dedicated GPU or Integrated graphics for the Windows machine or if it’s a desktop or laptop.

Problem has fixed itself !
Powered off last night, on this morning so far no “Not Responding” messages.

I’m running ES-8 asio, sample rate 44.1K, buffer 128 size.

I’m using a Behringer Neutron as my “modular” hardware synth
I’ve created a simple Rack and I’m communicating both ways Rack <–> ES8 <–> Neutron.
I suppose it’s a Windows thing why it didn’t work after the initial install of Rack and the ES-8 drivers.

Mac Book, don’t know again ?
I’ve just installed a Catalina update and Rack then installed
But Rack seems to be eating the processor i7 8 core, temperature up at 79c with Ableton running, was 67c
So I’m not going to be using Rack on the Mac, which is OK.

On Windows: Rack <–> ES8 <–> Neutron.
I take an output from ES-8 into a small SoundCraft mixer which has AuxSends to various effects.
LR out of the SoundCraft into my FocusRite which is connected to the Mac and Ableton

All seems to be working very well
Right then, start experimenting with Rack
Thank you

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Ahh, Windows: but now for some reason I getting audio dropout / clicks / crackling from ES-8 with Rack
I’ve tried everything in Rack, sample rate, buffers, threads
Tried ES-8 control panel settings etc.

So I quit Rack and loaded up Reaktor and created a simple patch, bingo No crackling.
Therefore Rack must be hammering my powerful Windows machine !
Not really enjoying my first Rack experiences at all

How basic was the VCV patch?

Very basic, Audio 8 i/o, a JW Clock and a Resonator.
BUT: I’ve solved it on Windows10:
1: USB cable length was 4 metres. I replaced this with good quality 1.5m and the crackling stopped.
The 4 metre cable was a cheap one from Amazon, works ok for midi to/from devices and controllers.
I now sample at 44.1K with 256 buffer

Others issues:
2: I run Rack, all ok. I then open Chrome with 15 tabs open and there is a buzzing and crackle as it opens.

3: If running as in 2 above I switch focus to Rack from Chrome, ok
But switching back focus from Rack to Chrome i.e clicking with mouse in a Chrome tab (web page) it crackles. USB Mouse !

4: If running as in 2 above : Occasionally typing with my keyboard there is a crackle, USB keyboard !

So my USB hubbed PC has issues.
However, simple solution, only run Rack on this PC
USB mouse clicks and moves are ok in Rack, no crackles

I’m happy to solely dedicate this PC to Rack when musicing, no other apps open :slight_smile:

Opening a Web browser while using an app that does real time audio processing will often lead to audio crackling.

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If you must use a very RAM hunger web browser while making music then in VCV Rack set threads to Real-Time this should get rid of the crackling of the buffer as chrome and other programs steals memory from VCV. If you want a less RAM hunger web browser there is Opera GX which is geared towards gaming, this is very minimal on RAM and the 15 tabs will take less RAM, Opera is Chrome on steroids Opera GX is Opera on steroids!

When patching you should set threads to 1 starting off and increase threads as you add more modules, this spreads jobs across cores.

I would highly recommend optimising your PC for Audio. There is an excelent and extremly detailed book written on this which can be found here: https://www.cantabilesoftware.com/glitchfree/


Opera was sold by its original Norweigan owners to a Chinese consortium in 2016. Just sharing in case anyone cares about that sort of thing and was unaware.

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