Polyphonic Modular made easy - featuring BASTL 1983
Your Modular synth can be more than mono! And it should be.
I’ve been messing with modular for the past year or so and it has been an incredible journey so far. Having a modular synth is so rewarding and exciting because you can create absolutely anything you want with it. I’m planning to do a full post documenting my full experience and sharing my best tips for anyone considering getting into modular very soon. So stay tuned for that.
My initial goal when I started my modular synth, was to create an instrument with 4 voices that I could sequence or play with a keyboard - something like the Vermona PERfourMER. I also really wanted to have a module that could cycle through the different oscillators by using a single sequence just like the Round Robin feature the Vermona and the Korg Mono/Poly have. To do that, I used a Switch module, called Switch by 2hp and it worked just fine. When my system got bigger, with more filters, envelopes, and VCAs, I realized I essentially had a polyphonic instrument but I was still unable to trigger multiple oscillators with the same keyboard. And that’s where the 1983 module by my dear friends at BASTL came up and I knew I had to try it.
In general, more than 90% of modular setups are monophonic. And by monophonic, I mean you cannot trigger chords by using a single keyboard controller or a sequencer. Because as an instrument, it may have more than just one oscillator. There are also quite a few modules that offer polyphony built in like the OXI Coral, Chainsaw by Acid Rain, Poly Cinematic by Knobula, and even Rings by Mutable Instruments. But those options are more of a complete polyphonic synth voice and you lack the flexibility of creating your own synth with the modules and sounds of your choice.
Today, we are talking about building a complete polyphonic instrument from the ground up. You can choose the oscillators, filters, envelopes, VCAs, and every single part of your dream instrument. That’s what modular is for after all!
Polyphony VS Paraphony
Before we start, let’s do a quick explanation of Polyphony and Paraphony. Paraphony, which you hear a lot on many synths, means that you can play multiple notes but all the notes run through the same filter, VCA, and envelopes (amp or filter) while Polyphony means that every note/voice you play runs through its own filter, envelope, and VCA. Even on standard synths, it’s trickier to have actual polyphony and it costs more simply because the synth has to have as many filters, VCAs, and envelopes as the voices it can play. And if you combine that with more than one oscillator per voice it gets even more complicated and expensive.
On a standard synth though, the Filter, for example, is most of the time a single filter with a single Cutoff and Resonance control. Or a single Amp envelope and a Filter envelope with the same settings. While the synth actually has multiple instances of the filter, you can only control it once and it’s been applied to all voices. It is just triggered each time you press a new note.
With modular, you can, of course, do both. Or even a mixture of polyphony and paraphony! And you don’t have the limitation of having a single filter, envelope, etc. control. Every voice can be totally independent in sound, timbre, filter type, filter settings, etc.!
BASTL 1983
Let’s now see how the 1983 module can help you achieve all of the above in your modular synth! 1983 is a MIDI to CV converter. That means it receives MIDI data from a keyboard, sequencer, or even your laptop and it converts that to CV and Gate signals. It has 4 channels of CV and Gate that can be configured to your liking and as you can tell, it can allow you to have up to 4 voices of polyphony!
Besides the 4-voice polyphony mode, you can have 3-Voice of polyphony + 1 Monophonic Voice, 2 Monophonic Voices with Velocity control, 1 complex Monophonic Voice, 4 Monophonic Voices, 8 Gates, 4 Gates with Velocity, 8 CC Channels, and, if that wasn’t enough, a 4-Channel Quantizer!
Another awesome feature of this module is that it can Tune your oscillators simply by tapping a button. You just need to connect the CV out of 1983 to your oscillator’s V/Oct input and then connect the oscillator’s output to the Listen input on 1983. Then you press the Tune button and it magically tunes the oscillator in a few seconds. It works best when you feed it a simple waveform like a Saw or a Square and while I don’t really know what kind of sorcery is behind that, it feels like magic. You can even use other tuning systems (for example A=432Hz) if you want to. If you have a modular synth with multiple oscillators I’m sure you know the pain of tuning every oscillator each time you want to play. I can’t stress enough how useful this is.
There are also two CV inputs for Transposing the notes by semitones, octaves, or fifths and for controlling Portamento that can be applied to all channels or channel A, channel A+B, or channel A+B+C.
Lastly, there is the option of also using 1983 as a four-channel Quantizer! You can set and edit the scales you want and now you have a Quantizer with four different CVs. There are, of course, dedicated quantizer modules but having one onboard is so cool and saves you a lot of money since a good quantizer module like Scales by Intellijel is quite expensive.
The only con I could find for 1983 is the following. The menu system is quite complex and you’ll need to refer to the manual a lot to navigate through all the modes and settings it has. The screen has just a number or a digit so you’ll have to remember what everything means each time. And if I wanted to be greedy, I would love for it to have 6 CV and Gate channels or the ability to expand it with a second one and have 8-voices of polyphony but that may be too much to ask for - and also, another reason to spend more money on modules.
1983 is full of features and a very useful module to have even if you don’t plan to always use it for 4-note polyphony. There are more things to it that I didn’t mention here, I included the most important to me and the things I use the most.
So how do I use it?
99% of the time I use the 1983 in the 4-Voice Polyphonic mode. That was the main reason I added it to my modular. I just plug a MIDI 5-pin cable from the Keystep 37 in the MIDI input and I then have 4 CV & Gate to distribute to my system. After all the patching, I can now play 4 notes at once and play chords using my Eurorack modules!
Another way I use it is for a round-robin scenario. I can play, let’s say, an arpeggio on my keyboard and run MIDI through 1983. What this does is that instead of playing the arpeggiated notes with one voice, 1983 cycles the notes between the 4 voices I patched with it. So I can have a single melodic line but every note has a different sound playing making it way more interesting to a regular arpeggio or melody. This is very similar to the PERfourMER and Mono/Poly and definitely more versatile because of all the options I have with my modules.
Why is this such a big deal?
Going back to the polyphony vs paraphony section, having polyphony in a modular synth gives you absolute flexibility! It’s definitely not the same as in a regular 4-voice synthesizer because every single part of the signal chain can be different and everything can be modulated on its own. For example, if you set an LFO to modulate the Filter Cutoff on a regular synth, it will be the same LFO for each voice and the same filter. While on a modular synth, you can do that per voice and only have one of the 4 voices having the Filter Cutoff modulated.
On a regular synth the oscillators are the same for each voice while on a modular poly-synth, each voice can be anything you want. You can have a completely different oscillator for each voice, run into a completely different filter, have a different envelope shape, etc. That opens up so many possibilities that are not available on other synthesizers. Your chords can be as complex and unique as you want them to be.
Flexibility is the most important advantage of a modular synth and if you add polyphony to that, there are no boundaries on what you can create! In my modular synth, I have 7 oscillators, 5 envelopes, 8 VCAs, and 4 filters (two of them with dual inputs). That means I can have 4 complete voices with their own signal chain. The only thing I can’t currently do is to also have a separate envelope for each filter which would be great but I’m sure I’ll add another envelope module soon with a few envelopes onboard. Or just share envelopes and use them for more than one voices to free up envelopes to use for the filters. And I’ll end up with a combination of polyphony and paraphony. Oscillators and Filters have the biggest impact on the sound so with my system the combinations of those two are already 56! And if you consider that you can have different envelope settings for each voice each time, the combinations are nearly endless with just an average Eurorack system.
From the moment I installed 1983 in my case and played the first few chords, I knew that this is it! Not being able to play chords and harmonies with my modular was a big limitation for me and now that’s not an issue anymore, I can’t see myself using another synthesizer soon. At the same time, let’s not forget that a modular setup can get really expensive really quickly. I really don’t want to do the calculations but I’m sure that my setup costs way more than most polyphonic synthesizers but now that I do have one, I truly think it is unmatched. The more you play with a modular synth, the less you want to go back to a regular synth. There will be a ton of times that you’ll think “I would like this to be able to do that“ using a regular synth so you’ll always end up going back to modular.
Conclusion
I don’t know if you can already tell but I’m so excited about this. 1983 opened up the door to modular heaven for me. I now have one thing that can do everything in regards to synth sounds and allows me to experiment as much as I want. I honestly cannot understand how polyphony in Eurorack is not such a huge thing yet. Maybe it’s because of the cost. Although I’m sure I can create a 4-voice fully polyphonic modular synth for less than 1.200€ - 1.400€. If you’re interested in that just let me know in the comments and I'll put a link with my design!
1983 is full of useful features. The auto-tuning is magic, the quantizer is so handy, and the polyphony it provides gives you so much freedom! If you already have a few modules and you can create a 4-voice polyphonic or even paraphonic synth, you should definitely give the 1983 a try. I’m sure that after getting one, you’ll be as excited as I am right now and that alone is worth the investment!
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