Sample Alchemy Introduction
Sample Alchemy is one of the great new features included in Logic Pro’s 10.8 release alongside the mastering assistant, beat breaker, the slip tool and rotate tool.
But we are going to focus on Sample Alchemy as it’s a very powerful granular, additive and spectral synthesis plugin that bolsters Logic’s already impressive sound library and instruments list.
Below is an overview of how to use Sample Alchemy, check out our full youtube video below too for some extra examples to get started.
How to use Sample Alchemy
Importing Audio
Granular Synthesis requires an audio file to generate new tones similar to a sampler, so start by loading an audio file into the main window.
By default the plugin will load up with Source A enabled and visible on your imported audio file. If you play a key you should be able to hear the audio file play and see a line playing through your audio file.
This A symbol shows us where the sample will start playing from for Source A and we can move this around our sample similar to a sampler plugin.
With A selected we can now view the main playback controls at the top of our waveform.
Playback Controls
The playback options will define how our synthesiser plays through our audio file. Here are the 5 options below and what they do:
Classic
Plays the sample from your position marker to the end of the sample. This also has a snap featured enabled snapping the position to the nearest transient.
Loop
The same as classic mode, however it creates a separate loop point. When the playback reaches this loop it will return back to the initial position and continue to loop as long as our note is held down.
Scrub
This is the more common playback mode for granular synthesisers as it plays the sample at the position point and doesn’t move. This creates a frozen/ drone like effect.
Bow
Similar to Loop mode but the sample plays forward in time until a point in the sample and then in reverse back to the start point, similar to a bowing movement used on a violin.
Arp
This is similar to classic mode but the notes inputted into the synthesiser will be turned into an arpeggio, similar to the MIDI FX plugin arpeggiator. Arp mode also uses different oscillators for different notes when enabled.
Source Controls
Each of these modes has a unique parameter that changes in the bottom left of sample alchemy in the Source section.
Classic – Playback Speed of the sample. (100% is the original speed of the sample, 50% is half speed.)
Loop – Playback speed of the loop section.
Scrub – Scrub Jitter adds a very small random movement to the position of our source, adding tonal changes.
Bow – Bow rate controls the speed of the bowing movement and can be set to synced rhythms.
Arp – Arp rate sets the rate of the arpeggio created.
In this Source section we also have 3 other controls:
Pan – Control the pan or stereo placement of our source.
Tune Coarse – Control the pitch of the source in semitones.
Tune Fine – Control the pitch of the source in cents. (100 cents = 1 semitone)
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Synthesis Modes
In the bottom of the plugin when we have Source A selected we can choose what synthesis mode we would like to use for our sample.
Granular
Granular synthesis is a synthesis technique that uses copies of the original audio sample called grains. Multiple grains play the audio sample in a very short loop that can be set by the grain size and these grains are offset when playing to create a smooth looping effect.
Granular Synthesis is taught in our Sound Design course along with other essential synthesis techniques too that you can check out here.
There are 4 controls:
Size – Controls the length of each grain.
Density – Controls the number of grains used.
Random Time – This will randomise the grain size for each individual grain when it plays.
Random Pan – This will randomise the pan for each individual grain when it plays
Additive
Additive synthesis tries to re-create the waveform at the selected position using individual sine waves, layered on each other at different frequencies.
This creates a much smoother re-creation of the waveform than granular synthesis but it can sound very digital.
As well as the controls changing below our synthesis type there is an extra mode in the top right of this section that can give different results and this also changes the dials underneath as well.
There are too many options to go through in this tutorial but overall the partials lock mode may not be in tune with the note being played so try the harmonics or partials modes instead.
Spectral
Spectral synthesis is a more advanced version of Additive synthesis and can create more accurate re-creations of the waveform in the sample above.
Spectral synthesis also has similarities to the way in which vocoders work, hence you may see some formant control options to change the tone of the sample.
Overall it’s best to play experiment with each setting in sample alchemy and see what sounds best to you!
Sources
In the top left corner of sample alchemy we have our 4 sources and a mixer view. Clicking on B, C or D will activate these sources and each source can have it’s own synthesis settings in the bottom row, which are completely independent of each other.
You can also choose different positions for each of our sources too by dragging their marker around the audio file.
This is one of the reasons why this plugin is so powerful and great for extensive sound design and instrument creation.
Filter
We have a filter in the bottom right corner of the plugin with multiple filter types found in other Logic plugins and the usual cutoff frequency and resonance controls too.
By default the filter is set with Global turned on meaning every source will be affected by the same filter type and settings.
Switching this off will allow for each source to have it’s own independent filter settings, you may need to turn the filter on with the power button in the top left first.
Envelopes
In the top right corner we have our Amp or volume envelope with the standard Attack, Decay, Sustain and Release controls.
By clicking on the word “Amp” we can swap over to the controls for our “Mod” or modulation envelope.This envelope hasn’t been assigned so it will have no effect on your sound by default.
Mod Matrix
Clicking on the Mod matrix button in the top right hand corner will show the modulation matrix.
To select a new target we need to click on or move a paramter within the synthesiser. If done correctly the “Target” setting should now say the parameter you want to control.
Below this we can assign different modulation sources to this parameter and se the depth or amount of the right hand side.
The plugin does includes some LFO modulation options but they are limited to time synced options only with a sine wave shape and no external controls over any other parameters and a random glide option too.
Sample Alchemy Global Settings
The circle with the three dots in the middle will show us the global, sample and midi settings.
This can be important for changing the polyphony mode, voice number, glide amount and pitch bend settings too.
The sample menu will alter some of the settings on our audio file including the original root note, which is very important for tuning. (Check the video to see how to do this.)
At the bottom we can also convert this Sample Alchemy into a regular Alchemy synthesiser plugin as they both use the same synthesis engine. This can be useful for more advanced sound design.
Play, Motion and Trim
Finally in the top left of the plugin we have three different views:
Play – The main view used to set the synthesis parameters, positions and all the controls mention previously.
Motion – By clicking on the record button at the top we can record position movement for our sources that will repeat every time we press a key on the keyboard. Extra settings can be found in the top right for loop length and duration too.
Trim – This allows us to edit the length of our sample using the start and end markers.
Summary and thoughts
Sample Alchemy is a great addition to Logic Pro and fills a gap in Logic Pro’s arsenal of sounds and plugins. It is very good at creating ethereal pads and drones as well as very interesting glitchy, futuristic textures and drums too.
Check out the video below for some audio examples.