COLOUR IN SYNTHESIS - Part 1: A practical tour of Logic Pro X’s Alchemy with wvnl

In this Lux Cache tutorial series, we explore the synthetic qualities of electro-acoustic sounds and how to generate warm and realistic sounding instruments within software synthesis. For part one, we invite producer, designer and developer wvnl to demonstrate his methods of building electro-acoustic percussive instruments from scratch inside Alchemy.

We ask you kindly to not share Lux Cache content outside of the Patreon, our contributors rely on your donations. All preview sounds/clips mentioned in this tutorial can be found in this accompanying Google Drive folder.

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CONTENTS :

1. INTRODUCTION
2. CHAPTER 1 - VOICES / MASTER
3. CHAPTER 2 - MODULATION / ENVELOPE
4. CHAPTER 3 - EFFECTS / CONCLUSION
5. CONCLUSION

Introduction

This is a practical how-to aimed at Logic X users, to accompany my Colour in Synthesis series.

Despite it being around for quite a while I’ve only really got to know Alchemy in the last 2-3 years, but now I often find it being my goto synth. It’s flexible and allows a number of different modes of synthesis; virtual analog, additive, FM, granular, sampling etc. While it can be overwhelming or less intuitive than other big synths, it’s rewarding to spend time with, I find inspiration can come quickly, and as a stock synth to Logic it’s worth getting the most out of it.
I didn’t feel there were loads of great examples/tutorials out there, so I wanted to put together a straight-forward tour, covering the basics plus some extra tips/quality of life stuff I’ve picked up.

Getting Started & Basics

If it’s your first time opening Alchemy, hit the ‘ADVANCED’ tab in the top left to bring up the main view.

Clear the default preset by going to: File → Initialize Preset

I recommend saving this initialised state as the default patch so you don’t have to do this step every time you load Alchemy. Go to: Plug-In Menu → Save as Default

OK so Alchemy’s main view can be broken down into 3 strips:

01 Voices / Master

Alchemy has four sources, which feed into a couple of filters, which in turn feed to the FX/amp. The tabs on the left let us dive into the individual sources.

→ Tabbed into source A

In the source view we’ve got a lot of what we’d expect for VA synthesis - an oscillator with a load of selectable waveforms, on the right are controls for unison and sync etc. Below that we have an additional Noise source we can enable, and on the bottom left we have three more filters. This is the first thing I like about Alchemy - it’s extremely generous with it’s filters; those two global filters, three more per source, plus you can just manually add more to the FX chain if you want.

The left side of this view will always stay pretty much the same, while the controls on the right swap out depending on the type of source.

Top-right we have some tabs for different types of source - although here’s the first frustrating part of Alchemy’s interface, most of these are initially greyed out and there’s no single way to set up/activate the different types of synthesis (and FM doesn’t even have it’s own tab); so we’ll go through using each type here.


01-A Synth Modes

Sampler & Granular

There’s 2 ways to turn a source into a Sampler or Granular. The simplest is to just drag & drop an external sample over the source, which makes this little drop zone menu appear:


The 2nd way opens up a browse & preview screen. Go to:
Source Menu → Import Audio


In the import screen make sure you set the desired Analysis Mode (bottom left) otherwise you’ll have to re-import.


Both of these methods let you batch import multiple samples and by default Alchemy will attempt to map them to the keyboard. How successful it is varies and sometimes needs adjusting. The Edit button brings up another full screen where you can change how samples are mapped etc.



The Sampler source is very basic and used alone probably won’t offer much over using Logic’s recently updated stock Sampler (previously ESX24), but it becomes extremely useful in layering multiple sources together and/or making use of the effects/macros. You can actually import whole Sampler/ESX24 instruments (.esx files) into Alchemy the same way you import raw samples.

The Granular gets a lot of use from me, particularly for either making pads or doing noisy/textural stuff. As far as granular synths go it’s pretty standard but adds a multi-tap mode (essentially creates layered duplicates of the granular but with offset sample positions) which gives a denser sound.


FM
So the fact that there’s no distinct FM mode actually makes total sense once we see how it works, but it is pretty idiosyncratic, I’ve not seen this setup in any other synth.

For a basic FM setup we want the amplitude of one waveform (the modulator) modulating the frequency of an oscillator (the carrier). Check out DJH’s previous intro to FM for a deeper look at FM.

To create a basic FM setup in Alchemy start with an initialised patch, and in source A set the oscillator type to Sine. Then go:

Enable filter 1 → select FM as the filter type

This filter is really just an additional Sine wave oscillator which is modulated by it’s input signal.
So in our case the source oscillator will be the modulator, and this FM Filter will be our carrier.

To finish setting up the FM filter we need to set it’s pitch and have it track to the keyboard.
Set the Note property to C3
Right-click Note property → Add Modulation → Note Property → Keyfollow
In the Modulation panel below → Set the Keyfollow depth to 100%

Now if we dial up the Mod property on the filter it will start to introduce overtones and transition toward a brassy sawtooth-like sound.

If we set Mod to something like 20% and scan through the Course Tuning of the source oscillator we’ll start to get all the nice metallic timbres we expect from FM.

This seems like a bit of a convoluted and clunky way to set up FM synthesis if we’re trying to do something along the lines of Operator or other FM synths out there, and honestly I really hated this set up when I first encountered it. I’ve since found it really valuable though; being a filter means it’s agnostic with regards to it’s input signal, so the modulator doesn’t have to be an oscillator, it can be a sample, a granular, noise source etc, or if we place it in one of the global filter slots the input can be a combination of multiple sources.

Here’s a trick I’ve used a number of times for noisy organic textures - it’s using a Granular source with some basic LFOs which are modulating position, grain size and density. Then that’s running into an FM filter. The filter pitch isn’t key tracked this time but it’s set to a really low note (B -1) and then modulated to a high pitch with an Envelope Follower which tightly follows the Granular. It results in this really thick but very clean & consistent sound:

🔈granular-x-fm.wav

Additive

There’s 2 main ways of using the additive synthesis, one is manually where you draw in your own banks of partials, the other is loading in a sample and having Alchemy analyse & convert the sound into partials over time.
Loading in a sample is the same as for the Sampler & Granular. How effective the analysis is depends on the type of sample; fairly clean one-shots of melodic instruments do pretty well, but a lot of the time Alchemy’s analysis can have a slightly garbled sound to it. We do have unique additive effects at our disposal though so this can be an interesting starting point for experimentation. Even just analysing some organic pluck/percussion sound and maxing the playback speed can have some nice results.

For manual additive, go to the Edit button in source.
In the Edit screen you can hit the Additive tab at the top and start drawing in partials below. There’s also abs to edit the detune and panning for creating richer sounds.

I use this manual approach most of the time, it’s well suited for making keys or melodic percussion sounds, or for drawing in a few higher harmonics to layer with other sound sources.

There’s 3 slots for additive effects, they all revolve around directly affecting the partials i.e. mixing between partial groups, or detuning & panning effects etc.

Spectral
Like with the additive synthesis, we can either start from scratch doing manual spectral synthesis, or we can load a sample and let Alchemy resynthesize the sound into its component frequency parts.
Loading in a sample is the same as for the Sampler & Granular. The resynthesis in spectral mode seems more successful than in additive mode, and can handle complex sounds.
The two main things we can do in Spectral mode is add spectral effects, or directly edit which parts of the frequency spectrum are being used.

To do this go to the Edit button in source.
In the Edit screen you can hit the Spectral tab at the top which gives us this view which is part spectrum display, part drawing program.


Here you can either paint or erase parts of the frequency spectrum - directly altering the resynthesized sound, or use Mask to non-destructively edit which portions are heard.

For the manual approach, just skip loading in a sample and go straight to the edit page and start drawing in your own shapes.

Most of the spectral effects seem geared toward pads & ambient textures, and are tonally alike. I think the standouts are Frequency Shift - a spectral filter which works nicely on percussion, and Metallize which adds a metallic resonance which can sound good if you dial back the settings.

Personally I find the spectral mode in Alchemy more novel than useful, and I end up spending a lot of time trying to fix the sound. But I think it’s probably suited for people who like a try stuff & see approach, and the manual drawing at least feels a bit more immediate and can be nice for creating more noisy/glitchy stuff.
01-B Morph

The final left-hand tab gives us a few ways to morph between the 4 sources, either using crossfades, or by actually transitioning all the source parameters individually. This can make some really nice movement in sounds, and is great for pads/drones. I’ve also found myself using this for drum/impact sounds - making one source the transient, and another the body/tail, and then quickly morphing between them using a fast envelope.

02 Modulation / Envelope

We can modulate any property with: Right-Click → Add Modulation

Under the Modulation panel we can then set the depth. Left-clicking any property will list all of it’s modulations in this panel.

LFO & ADHSR envelopes are pretty standard. The MSEG envelopes let us manually draw in envelope shapes and really I wish all synths had them. They have an extra advantage - we can create one-shot envelopes by deleting the furthest right node and setting the Loop Mode to Continuous. We can also save envelope shapes as presets. The disadvantage of MSEG’s is we can’t modulate it’s properties such as attack & release like we can with ADHSR.

There’s also this little basic SEQUENCER which is nice to have though I’ve never really used it. The ENVELOPE FOLLOWER I have found very useful for creating organic textures. You can point it at different parts of the synth - individual sources, pre/post FX, or you can point it at other modulators like LFOs and using the attack/release create more natural shapes & transitions.

In the Modulation panel on the left, there’s a tiny dropdown between a modulation and it’s depth - this is where the MODMAP gets used. It remaps a modulation’s values before applying them.

A nice trick I use these for is creating subtle per-note detuning which can bring a lot of life to a sound, particularly on percussion/plucks. To do this go to the Master section and:
Right Click Fine Tune → Add Modulation → Note Property → Keyfollow
In the MODMAP dropdown select map 1
Now in the MODMAP itself set Snap X to Key

This shows the map as a keyboard layout where we can paint in values. Basically go to town painting in random values (once you’re happy with it you can save it as a map preset so you only need to do this once).


Now we can dial in the detune by upping the depth on the keyfollow modulation.

03 Effects / Performance

So on the bottom strip we have tabs on the left for Performance, Arp & Effects.

03a Effects

The Effects section has a MAIN channel plus 4 more, so it’s possible to send different voices to different FX chains, as well as save/load FX chain presets.
Overall I’d say the Effects in Alchemy are not very exciting when compared with other synths but there’s a few special things going on:

Convolution
Probably my most used effect, I’ve always been impressed that this thing has a built in convolution reverb which lets you load in your own impulse responses, it adds a huge amount of variety to achievable sounds. This is basically the same as Logic’s Space Designer.

Multimode Filter
This lets you load any of Alchemy’s filter types within the FX chain which can be really powerful. Sometimes the best place to add something like a Comb or FM filter is right at the end, or you just want to get a patch sounding as complete as it can be before relying on post FX.

Waveshaper

A pretty standard waveshaping distortion but it’s a nice addition with good presets.

03b Performance & Arp

The inbuilt arpeggiator has a good selection of modes and lets you set custom pattern lengths. It also lets you create 16 separate patterns so you can do some nice generative rhythms by using a Random Hold LFO to modulate between patterns on each beat/bar.

The main Performance section has 8 assignable controls/macros, a couple of XY pads, and it also has this snapshot transform pad which honestly I’ve never used, but if you like making patches with lots of automatable parameters then this is pretty nice - you can name each snapshot and Alchemy has a randomise function for their settings.

Extending Alchemy

Going back to the Noise sources - It’s possible to extend the types of noise available by dropping your own noise samples in the folder Alchemy uses.

To do this go to your Applications folder in Finder, and go:

Right-click Logic → Show Package Contents
Then go to:
Contents → Frameworks → MAAlchemy.framework → Resources → Libraries → WaveNoise

Drop your own .wav samples in here and next time you load Logic they’ll appear in the Noise dropdown menu.
Couple of warnings - first, obviously don’t move/mess with anything else in your Logic file structure. Secondly, any patches you make using these non-vanilla noise samples will show a missing file error if you load them on any machine which doesn’t also have them installed - unfortunately Alchemy’s Save Consolidated option only consolidates samples which have been loaded through the synths interface.

Conclusion

Alchemy definitely lacks some of the sharpness and cleanness of synths like Serum - but just the number of layers and filters plus the combinations of source types are great for freely creating without worrying too much about limitations. Having it as a stock tool is extremely convenient and it’s worth spending some time with, and I hope this guide helps make it’s interface and tools a little more accessible. From here we’ll be truly getting into the main theme of this series - creating synth instruments with acoustic characteristics, and breathing life & colour into synthetic sounds.

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Luke Twyman (wvnl) is a producer, sound artist, designer & web developer based in the UK. You can view their work at

You can follow them on Twitter @_wvnl and view their portfolio at wvnl.xyz.

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