Writing challenge #3: Chiptune edition!

[Ben Asaro]

As my Subharmonicon deep dive is winding down and its subsequent composition is starting to take shape, I’m already starting to prep for the next deep dive: chiptune!

I’m rather excited about this one as I’ve had two Twisted Ekectrons AY3 modules for a couple of years and haven’t put them to much use. I also have a tracker sequencer in the form of the NerdSeq which does all of the things a tracker should in terms of tracker effects (also totally unexplored by me until now)

The AY3 modules will give me 4 square wave VCOs which can play as intervals or arpeggios, and 2 pitched noise sources.

As chiptune looks like a large part of its aesthetic its economy, I’m really looking forward to the challenge!

[Arpangel]

Looking forward to hearing the results Ben.
I’m looking at the Mega FM, and also, bemoaning the lack of FM Eurorack modules, are there any decent ones? can’t think of any pure FM modules out there with decent interfaces.

[Ben Asaro]

I like the fact that modular doesn’t just hand you finished sounds. FM is definitely possible in modular as long as you have the time, patience, and number of required modules.

The MegaFM looks cool but I doubt I will ever get one.

[Arpangel]

I like the fact that modular doesn’t just hand you finished sounds. FM is definitely possible in modular as long as you have the time, patience, and number of required modules.

The MegaFM looks cool but I doubt I will ever get one.

I don’t think I’ve ever set-out to deliberately achieve a set idea that I’ve had, like FM for instance, with modular.
That’s just beyond my patience, it’s always been an unmediated exploration of some kind.

[Ben Asaro]

DAY 1. Here we go! Another deep dive, this time into writing chiptune. Since I'm starting at Square One, I figured it would be helpful to run through both square wave voices and both noise sources from C-0 to C-9 to see what the actual range is, as well as to see how close the tuning is on these 43 year-old chips!

HEADPHONE WARNING -- START LISTENING AT LOWER THAN NORMAL LEVELS, THE LOW VOLTAGES GOING INTO THE VCOs MAY CAUSE DISCOMFORT!

https://soundcloud.com/user-329043613-5 ... osc-sweeps

There's a surprising amount of low frequency grunt on the lower notes. Otherwise, it sounds pretty much as described on the tin: 8 bit square waves. There is a bit of tuning drift on a couple of notes, but it's actually more stable than I thought it would be!

[Eddy Deegan]

An interesting experiment Ben ... chiptunes are close to my heart and I look forward to seeing what you come up with during the course of the process. That first track hurt my ears a bit; might be wise to have a headphone warning on that one!

I don't know if you use plugins at all but as a heads-up if you do there is currently a free Retro Decimator plugin available from Inphonik (you can get it here). It's a module from their (non-free) RYM2612 FM synth which is based around an emulation of the classic Yamaha YM2612 sound chip as used in the Sega Genesis/Megadrive.

[Ben Asaro]

Oh, that's good to know! I think if my AY3s were lost or damaged, I would probably be disinclined to replace them and would definitely switch to a plugin.

Thanks for the note about the levels, I checked on my cans and didn't hear anything untoward, but I had the volume pretty low!

[Martin Walker]

DAY 1.There's a surprising amount of low frequency grunt on the lower notes.

You're not joking Ben - my RME DIGIcheck spectrum analyser indicates there's as much energy in the 1/3 octave centered around 25Hz as any other band!

Martin

[Ben Asaro]

DAY 2. What I am looking forward to with this challenge is not only dipping my toe into a new genre, but also learning some of the deeper functionality of the NerdSeq.

So, with two melodic voices, I thought, what better way to achieve both goals than to start with someone who is a master of two voice composition: JS Bach.

I figured one of the 2 Part Inventions should suit.

https://soundcloud.com/user-329043613-5 ... nvention-1

As you can hear, this needs some finesse! But at least the notes are entered!

[Ben Asaro]

DAY 3. Took Invention No. 1 a bit further and was able to dig into the NerdSeq's deep envelope automation! This really helped to smooth out the 'touch tone phone' type of sound present on my first pass.

https://soundcloud.com/user-329043613-5 ... ion-1-rev2

There's some dodgy tuning around the 40 second mark, but that's to be expected; I don't think these chips are renown for their rock solid tracking!

Once again, the foundation on the lower notes is suprisingly solid, even with a bit of resonance added to scoop some of that girth out (via Doepfer LPFs). I think I prefer the control from the NerdSeq's envelopes over my Intellijel EGs for this; they are much snappier and more versatile. The Make Noise EGs would probably be perfect for chiptune, they are super snappy, but I only have one ... if only I had a Maths lol!!

I continue to find the NerdSeq's manual very difficult to decipher; fortunately, a YT video made after the 1.22 firmware had the bit of information I was looking for to get the envelopes to work properly. There are a total of 8 envelopes available and they are part of a matrix, so you can assign them with a very fine degree of control. For what I'm doing, ie the most basic application, I think it's assumed that the user just knows how to get them to work.

[Ben Asaro]

Sidebar 1. My next goal is going to be attempting to write a percussion track using the patchable noise outputs from the AY3. However, as my modular is currently being used for another composition, I don't have any spare patch cables!

As soon as that's done I'll be returning to our reguarly scheduled program.

[Ben Asaro]

New song is done and dusted (aside from final details), time to get back into the chip tunes!
Next up: trying to create a percussion track using noise!

[Ben Asaro]

After tinkering around the last several days, I think I've come to the conclusion that either a) I'm rubbish at writing chiptune, b) chiptune doesn't really work well for modular, or c) I'm uninspired to write anything interesting using the chiptune modules.

I think that the order is probably b, c, a (which is hilarious because CBA lol) but the combination of the three is what's grinding this to a halt. The biggest hurdle I'm facing is that you can't easily change gate length in eurorack without using a keyboard, so the notes all have the same length. This makes melodic expression really difficult.

I don't mind the challenge of trying to figure out how to vary the gate length, but in the end I have to think realistically: if I'm not going to write any chiptunes for release, what is the cost:benefit to doing so.

So I may be putting this challenge aside for a while until I can think of a way round this issue.

[Martin Walker]

Hi Ben,

If it's of any help, my goal with chiptunes always was to cram as much variety and complexity into the three channels I invariably had available. This meant changing 'voices' on a beat-by-beat basis so I could create (for example) drums & bass on one channel, multiplexed chords on the second, and a melody/harmony line on the third.

It was all this switching between sounds, plus any real-time variation such as PWM, Envelope and frame by frame pitch variations (even one-offs for the attack of sounds) to keep the interest from wandering.

It was a bit like a jigsaw puzzle, trying to fit everything in, but gave the impression of a much busier arrangement. You really do have to play to the (very limited) strengths of chiptune hardware, to push the boundaries, otherwise experiments can end up sounding like a digital watch tune

Good luck!

Martin

[Ben Asaro]

Thanks, Martin; that's actually quite helpful!

[Martin Walker]

Thanks, Martin; that's actually quite helpful!

[Eddy Deegan]

To supplement what Martin wrote, I'd say chiptune-style material needs a fairly powerful sequencer in order to drive the basic tones in different ways.

The Polyend Tracker, for example, is essentially a chiptune machine at heart and in order to do that it offers many of the same sequencer features found on the original 8 and 16-bit trackers (and I suspect on many a music programmer's custom driver as well) including such things as different tones per step per channel and the ability to apply real-time 'FX' to each step to rapidly modulate or otherwise effect it in different ways.

The Squarp Hermod would be a good bet in a purely modular setup as it shares a lot of the relevant feature set.

Chiptune music is a lot less about timbre and a lot more about technique. Even though there are highly recognisable timbres from the original audio hardware in the C64, Amiga and ST families, if you were to apply the same complex sequencing techniques to virtually any basic tone (and probably quite a lot of not so basic ones) you'd get something instantly classifiable as a chiptune.

Another common technique is to rapidly arpeggiate a single channel over the notes in a chord in order to give the illusion of polyphony on a monophonic channel.

If you want to try a 'quick and dirty' experiment to simulate this, try playing the Bach piece using the same tone you did before but for the higher part use a square LFO to modulate the pitch up (and subsequently back down of course) by an octave at 32nd or 64th note intervals... or even asynchronously but in that ballpark. That should sound fairly chippy I reckon

[Ben Asaro]

Thanks, Eddy; appreciate those insights, they are quite helpful!

The NerdSeq is a full blown tracker sequencer, including classic tracker effects and a host of other features, too.

The ornaments in the Bach piece are actually table effects inserted on those steps in the NerdSeq.

Also, the AY3s are capable of playing arps instead of notes.

I will take all of this info to heart, and see what I can come up with! Thanks again!

[Martin Walker]

Chiptune music is a lot less about timbre and a lot more about technique. Even though there are highly recognisable timbres from the original audio hardware in the C64, Amiga and ST families, if you were to apply the same complex sequencing techniques to virtually any basic tone (and probably quite a lot of not so basic ones) you'd get something instantly classifiable as a chiptune.

A hearty +1 to this advice from Eddy.

To hopefully shed some more light on this topic, here's an multi-track oscilloscope video for possibly my most famous 8-bit SID theme (from the shoot'em up Armalyte):

To listen, click on this link: https://www.youtube.com/watch?v=raLQepqKulU

Martin

[Ben Asaro]

Thanks to everyone for the great tips and tricks, but this challenge has a sad post script, as I've decided to sell off my chiptune modules to make space for something(s) I will use more often and get more pleasure from.

There is something about the way chiptune is written that consistently leaves me feeling lost and/or flustered. I love it as a genre, but I'm willing to accept defeat on this one. It will simply take too much time for me to develop any proficiency at it. I think part of this is in no small part due to the Subharmonicon and Lyra-8 entering my workflow; they have definitely helped define a compositional style that's more in keeping with type of synthesis I enjoy.

However, I do love the NerdSeq and I think trackers are wonderful and will continue to use is as my primary out of the box sequencer!