Review – Hollow Sun GUI Shell


Hollow Sun has come up with a brilliant idea, but one so very obvious it begs the question “why didn’t somebody think of this a long time ago?”. Introducing GUI Shell.

by David Baer, Sept. 2013

Shell Game

Kontakt is an extraordinarily powerful instrument.   But let’s be honest – it’s never going to win any awards for having an intuitive interface.  Now, I confess that I have not undertaken the hours of study required to learn how to program this beast.  After all, I have far more user friendly instruments in my collection which are so much easier to understand if I want to do my own sound creation.

In a perfect world, all my Kontakt sounds would be unencrypted SFZ files.  Any time I wanted to do some programming of my own, I’d just transport them over to Alchemy (my first choice but there’s also Synthmaster, Rapture, Dimension Pro, and no doubt a few other synths I’m overlooking) and get down to business.  I understand Alchemy sound programming far, far better than I do Kontakt.  Sadly though, it’s not a perfect world, and my Kontakt samples, of which I have an impressive and ever growing collection, are encrypted and are only available for use within Kontakt.



Well, it’s Hollow Sun to the rescue!  Hollow Sun’s recent offering, the GUI Shell, has such an obvious value that it’s amazing no one thought to do something like this a long time ago.  The concept is simple.  Rather than offer an interesting collection of samples with a custom graphic front end, as is normal practice these days for Kontakt sounds suppliers, GUI shell is a fully functional synth interface into which you can insert any Kontakt samples you have handy.  Of course, you can import “foreign” types of sample files that are Kontakt-compatible.  But the real value in my opinion is that GUI Shell offers a mechanism for easy programming of your captive library of encrypted Kontakt sounds – the ones you can’t play outside of Kontakt.

GUI Shell requires the full version of Kontakt 4.2.4 or later.  It costs a meager twelve dollars (USD) or thereabouts.  Included are some simple waveforms which are usable.  But the real payoff is when you use GUI Shell with more complex and interesting sound samples, which Hollow Sun also has on offer in abundance (and at no-brainer prices to boot).

We’re going to take a close up look at the GUI Shell here and I’ll pass on a couple of not-so-obvious techniques to make your experience potentially more fulfilling.

It’s fair to say that GUI Shell does require some basic understanding of classic subtractive synth programming.  If you don’t know what filters, envelopes, LFOs are all about, you better just stick to presets the way you must do with all your other synths.  But if you are comfortable with basic synth programming skills then GUI Shell is a piece of cake to use.

The pictured interface should tell most of the story, so let’s start with the non-obvious aspects of this.  The idea is that GUI shell offers you a framework into which you can insert one or more sample set layers.  As stated earlier, these can come from any resident Kontakt library or from outside Kontakt-compatible sources.  We’ll look at setting up the individual layers in more detail in a bit.

You start by selecting a template.  There’s one for two, three and four layers (if you just need one layer, use the two-layer template and leave the second layer empty).

Once you have your layers in place, you can program them as you would any subtractive synth.  The programming can be done on individual layers or on all layers by selecting from a drop-down (see illustration).  You can program some parameters as layer-specific and others as all-layer-applicable.  For example, you could slightly detune several layers (layer –specific) but have them share a common vibrato under LFO control (all-layer-applicable).  And it could not be more straightforward!

Synth Programming Ease

Because the envelopes and LFOs are “hard-wired”, sound design using the GUI shell is about as easy a synth programming exercise you’re ever likely to experience.  The top rank of controls is for “Oscillator”, Filter and Amplifier.  I wrote “Oscillator” in quotes because it’s obviously not a tradition VA oscillator but a Kontakt group playing samples (we’ll look at setting those up shortly).  We control tuning and level here and can modulate the pitch with an envelope or LFO.  The Balance control lets us give more weight to lower or higher notes.  There’s an interesting possibility here in using this in complementary fashion between two layers, the cross-fading varying according to keyboard position.


Next to this we have Filter with the standard Cutoff and Resonance controls.  On offer are conventional low, band and high-pass filters, two vintage modeled devices and a band pass filter.  The vintage options are a Moog ladder filter and NI’s filter from the late, lamented Pro53.    The LED between Velocity and Keytrack, when clicked, exposes controls to dictate the amount of modulation of cutoff from the filter envelope and LFO.

Finally, we have Amp controls for Volume, Pan and Velocity sensitivity.  The LED between Volume and Pan, when clicked, exposes controls for modulating volume and pan position with the Amp LFO.

The next rank contains the controls for three identical envelopes.  ADSR.  Need a more detailed explanation?  I thought not.


And under the envelopes, we have three identical LFOs, dedicated to pitch, filter and amp/pan respectively.  Once again, this requires almost no explanation.  The three radio buttons on the right allow you to modulate the LFO depth with either mod wheel or aftertouch, or simply let it run at a depth controlled by the destination’s modulation-level controls.


Finally we have the row of effects: distortion, chorus/flanger/phaser, echo and reverb.  Everything is largely self-explanatory here other than the reverb radio buttons, which stand for Hall, Plate and Spring.

And there you have it … right there on a single panel.  The documentation goes into things a little more deeply than I’ve done here, but there’s not much more that needs explaining.  Until, that is, we have to dive into the depths of Kontakt to set up our samples.  Then, things can get a bit scary for the Kontakt neophyte.

Deep Dive

The documentation does a decent job of leading you through the basics, but necessarily skips the great detail needed to explain how Kontakt’s groups and zones are architected.  In particular, the documentation is written as if the user will set up the samples into zones by importing samples and mapping them accordingly.  My experience in the past when I’ve tried it is that it’s hard work, prone to error and no fun at all, especially if the same file names don’t tell you the root key of a sample.

But I’m going to suggest that the typical GUI shell user will want to go about things differently anyway.  Rather than setting up your own zones, it’s far easier to copy an existing group’s samples, for which all the hard work has been done for you.  You just want the samples all properly mapped to be made available to GUI Shell for your own tweaking.

It’s easy to do this, although not obvious.  But just follow these instructions and you’ll enjoy success.  The GUI Shell documentation already shows how to put the instrument into edit mode by clicking the “spanner” icon (“spanner” is a British word which in English means “wrench”).

To grab an existing set of samples from another instrument, bring that instrument into the rack, and put it into edit mode.  Click the Group Editor and Mapping Editor buttons (step 1 as pictured).  Select the group whose samples you want to grab (step 2).  Next right click in the zone window (step 3) and click “Select All”.  Finally, click “Copy zones with samples”.  We’ve got what we want, so close the “from” instrument at your convenience.

Now we go back to GUI Shell and put it into edit mode.  Select the group you want to provide samples for, right click in the zone window, and click “Paste with samples”.  That’s the whole process.  You’ve now got a group that’s ready for action.  Let me suggest that you rename the group accordingly at this point.  It’ll make your sound design session run a lot more efficiently.  Don’t worry if the names don’t seem to “register” with Kontakt immediately.  They may still appear as “Group 1” or whatever for a while, but they will eventually become fixed.

One caution.  When you’re playing about with this, you might notice that you can just click on a group name and copy it (with samples).  Quick yes, but it does not work with GUI Shell.  You can paste the copied group into the GUI Shell group edit window, but the control panel will not recognize the new group.  Just stick with the copy-zones approach outlined above and you should have no problems.

Let’s take this opportunity to suggest that you decide to purchase GUI Shell, you should spend another couple bucks and get Hollow Sun’s JayPea instrument, which contains a small but delightful trio of multi-samples that will make your GUI Shell experience an immediately rewarding one.  But anything you’ve got available in Kontakt is grist for GUI Shell’s mill.  Between my Hollow Sun and Hideaway Studio libraries alone, I’ve got an unlimited amount of potential just sitting there waiting to be unleashed.

Just Like Keith

So, now you’ve got all you need to proceed using Kontakt for your dazzling Keith Emerson impression, right?  No?  Oh, you mean the fact that there’s no proper portamento capability like that found on any respectable analog synth.  Well, never fear, there’s a solution for that as well, and it’s easy as can be… once you know how to include it.

 Kontakt ships with a collection of utility scripts, but the manual documenting them does not bother to explain how to access them.  And, yes, we have to go back into the scary waters of Kontakt’s edit mode to get things accomplished.  But honestly, once you see this done, you’ll understand how un-scary it really is.

Just do the following.  Take GUI Shell into edit mode, if not there already, click Script Editor (step 1 as pictured), select the second tab (the first unused one), navigate the menu structure and select Unisono- Portamento in the Performance category (step 2).  This will add the panel pictured below.  The portamento controls are obvious (plus you have some unison fattening thrown in for good measure).  The only downside is that you need to open up GUI Shell in edit mode to adjust the portamento settings.  While this is a bit annoying, there is something you can do to avoid this.  Any of the portamento knobs can be MIDI-learned and used from the main panel.




So now you’re all set.  Or at least you should be.  For some reason, I still can’t quite get my Keith Emerson impression to come off as really convincing.  I know, you’re probably thinking the same thing I am… there must be something wrong with my MIDI rig.


You may also be interested in

Browse SB articles

SoundBytes mailing list


Welcome to SoundBytes Magazine, a free online magazine devoted to the subject of computer sound and music production.


If you share these interests, you’ve come to the right place for gear reviews, developer interviews, tips and techniques and other music related articles. But first and foremost, SoundBytes is about “gear” in the form of music and audio processing software. .


We hope you'll enjoy reading what you find here and visit this site on a regular basis.

Hit Counter provided by technology news