Joy of Synths #11: Modulating the Kobol Expander
A non-musician’s guide to creating sounds for podcasts, videos, and sampling for music using analog synthesizers.
Kobol Expander Opportunity
I don’t want to say this is a problem. Rather, the Kobol Expander semi-modular synthesizer presents an opportunity for modulation. With the Attack, Decay, and Sustain controls, all three can be modulated with voltage. If you are not patching cables into it then the Kobol is not living up to its full potential.
Voltage Sources
In Joy of Synths #10 I proposed using Eurorack Modules as a source of control voltage for modulating the Kobol’s many patch points. That is still valid, but I found my first and least favorite semi-modular synth is the best for playing/controlling the Kobol.
STYLOPHONE GEN R-8 Semi Modular Synth
The Gen R-8 was announced and produced in a limited run in 2019. I bought it because I liked the sound demos and its design.
It’s a solid build with two oscillators, a multi-shape LFO, switches, a 3 octave touch plate and a sequencer. Gen R-8’s sound range goes from screaming on the high end to growling on the low end. It has a drive dial to really push the signal. Which is cool but overall I’m not thrilled with the sounds I’ve been able to produce. I love delays but this one doesn’t quite play right compared to the KO2’s delay.
I don’t see Gen R-8s much listed for resale. I’ve held onto it because it’s so heavy and I hoped as I got better with synthesis that I’d be better prepared for playing it.
Well, I spent an hour playing with it solo on the first of the year. The sounds did not impress me. Then I connected it the Gen R-8’s Gate out to the Kobol’s Gate In, and listened to the Kobol. It was night and day, with the Kobol’s sounds being so much more interesting, cleaner, and transformed by the turn of a dial than a morning’s worth of tinkering on the Gen R-8.
I CAN SEE CLEARLY NOW
All the things I didn’t understand with the Gen R-8 now make sense now that the Gen R-8 is connected to the Kobol. See, the Gen R-8 is not really designed to patch into itself so much. A lot is prewired. For example, push button switches allow you to send the LFO (low frequency oscillator) to modulate the oscillator 1 or 2 or filter cut off frequency, or all three. The outs are meant to go to another synth, be it a eurorack or semi-modular.
Its inclusion of MIDI OUT shows that the designers thought about using the Gen R-8 as a MIDI or CV controller. And wow, did they ever design the perfect controller for the Kobol.
What’s cool about the Gen R-8 is that it has an LFO with two outputs, multiple wave shapes, and speed and depth control. In contrast, other LFOs offer speed controls but they may not have a wave shape selection aside from a triangle wave or sine wave, nor will they offer depth control. The depth control makes this LFO super useful for modulation.
It also has a touch plate keyboard like the regular Stylophone. This spans three octaves, so you can hear the difference between high and low by playing either end of the touch plate.
The Gen R-8’s sequencer is easy to make sense of, with 8 stored patterns that can be switched with the turn of a dial. There is a speed control, and you can transpose while playing by a sequence by selecting a higher or lower “key” of the touch plate.
A MESSAGE FOR MIDI: Use Voltage
The MIDI OUT did not work upon first connection. There may be something I’m missing, but I don’t really care about MIDI when I have sequencer outputs for CV Out, which is 1 Volt per Octave, and Gate Out.
Modulation Sources
Low Frequency Oscillators with various wave shapes can be used to automatically raise and lower a dial with a CV input jack. LFOs can move a dial control at a faster rate than a human hand, and sustain the rate for far longer.
Envelope Generators are good for this, as well, generally placed with Voltage Controlled Amplifiers and Filter frequency cutoff dials.
Oscillators are used, too, and their different wave shapes will produce different sounds when modulating frequencies.
Which is the best for modulating what controls?
This is where you experiment. Start by patching different modulation sources into a control input jack and listening for a result while slowly turning dials.
This is why you want a lot of patch cables of different lengths and a few splitters to multiply an LFO signal for several input jacks.
For all possibilities, the modulation source is what you have available. Try using another synth just as a modulation source.
Gen R-8 as Voltage Controller
But what’s fascinating to me about the Gen R-8 is that it is better as a controller of the Kobol than playing it by itself. I’m surprised that they gel so well together, to the point of being close to the same length, and the Gen R-8 having a top row of patch points so you don’ have a lot of cable clutter while adjusting the Gen R-8 dials.
I have about 28 spare blue PGH patch cables from buying the Pittsburgh Modular module in November. Those are the right length for connecting the Gen R-8 to the Kobol Expander.
(Note: As I wrote in Joy #10, the KO2 can be used as a MIDI controller for the Kobol 2. Since that works via MIDI, I can only attribute the Gen R-8 to possibly being broken MIDI outputs. I mean, I never tested it because I just used the Gen R-8 as a stand alone unit. Anyways, it’s fun connecting CV and Gate outputs.)
Alright.
That’s all I have to say about it on this first (and fifteenth) day of 2024. In short, it’s amazing that the two work together so well. The Gen R-8 has found its true purpose as a controller and control voltage source for modulating the Kobol Expander’s many dials.
End Note 1/15/2023
2024: Stylophone Score
Stylophone announced pre-orders for a new Theremin and a $259 Eurorack compatible drone synth. It’s similar to their Gen R-8 minus the touch plate and envelope generator. The 2024 synth adds a filter per each Oscillator, and 2 LFO outputs with 2 unique wave shapes, plus reverb and delay. Plus it’s in a powered box with speaker and can be added to a Eurorack system if you remove it from its powered box. In form it’s like a Korg Volca Modular synth.
I listened to the sound demo. As a Gen R-8 owner, I don’t need a duplicate device. It’s lack of touch plate controller and sequencer don’t make it a great instrument for modulating another synth. This means you can’t send CV OUT to a Volts per Octave for Oscillator pitch nor Gate signals for note on/off duration.
While it’s not for me, this may be your dream synth.
In general, evaluating gear through reviews be it print or video is difficult because the reviewer’s sound preferences are either aiming to recreate a sound once heard or they are searching for a new sound, or something else altogether.
Specifically, I’m getting sounds from the Kobol Expander I did not hear in the demo or other play throughs. This is before modulating it with the Gen R-8. Well, I can’t expect anyone else to experiment with patching the way I do. The Kobol is a $199 synth, so it may be dismissed as disposable by some so they don’t explore beyond the basics and no patch cables to rewire its sound.
Ultimately, it’s faster and less frustrating to just buy the instrument from Amazon as seller/shipper and return it if it’s not to your liking. Just keep the box they shipped it in. You are responsible for giving a sealed box for shipping to UPS Store.
But a lot of cool instruments are not sold on Amazon.com, or they are sold by a second party with their own return policies. Perfect Circuit has a fair return policy, as does Sweetwater. Just pay attention to their return policies so you don’t get hit with restocking fees or a return refusal.
In the case of Stylophone’s new offerings, these are on preorder with no money down, probably to gauge interest before they commit to a run. I don’t believe returns are an option once you commit to a final order. Resale is the better solution to recouping costs if you don’t care for the sound.
Finally, NAMM is happening at the end of January, with likely many new synthesizer announcements. Check https://synthanatomy.com for their updates. That’s where I’ll be checking, along with https://synthtopia.com
Joy #12 will arrive on 02/01/2024. Cheers! - Anthony Torres
This issue is sponsored by CoWolves. Buy vinyl at https://discogs.com/seller/cowolves.
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