The Controller panel Modulation Bus routing section

Editing parameters

Editing the various parameters on Thor is very straight-forward.

Buttons

Switches and sliders

Knobs

Waveform displays

Text displays

  1. Tap the desired display to bring up a list with the selectable items.
  2. Tap the desired item in the list.

    The item is selected and the list is automatically closed.

Saving patches

  1. To save a patch, tap the Save (disk) icon on the Menu bar:

    The Save Patch dialog appears.

  2. Tap the Save button in the dialog to save your edits and overwrite the original patch.

Basic connections - a tutorial

There are certain pre-defined connections available between the Oscillator 1-3 slots and the Mixer, Filter 1/Shaper, Filter 2 and Amp sections. On the panel itself, lines with arrows are shown to indicate the standard signal paths.

In the following tutorial we will create a standard setup using two oscillators and two filters to demonstrate Thor basics and the (standard) signal path:

  1. Tap the Patch Name in the Menu to open the patch browser.
  2. Tap the Templates tab at the bottom of the patch browser.
  3. Tap the “Simple Analog (Reset)” patch in the list and then tap outside the patch browser to close the browser.

    The “Simple Analog (Reset)” patch is a basic setup with an Analog oscillator in Oscillator slot 1 and a Low Pass Ladder filter in Filter slot 1 loaded. The “Simple Analog (Reset)” patch is exactly the same as the Init patch in the Propellerhead Reason version of Thor. A connection between Oscillator 1, Filter 1 and the Amp section is already activated, so you get a sound when you play.

    Below the Oscillator 1 slot in the upper left corner are two more slots, currently empty. These are the Oscillator 2 and 3 slots, respectively. The three Oscillator slots are basically identical in that they can each be loaded with one of 6 oscillator types.

  4. Tap the arrow pop-up in the upper left corner of the Oscillator 2 slot, and select a second oscillator from the pop-up list that appears.

    The following oscillator types are available; Analog, Wavetable, Phase Modulation, FM Pair, Multi and Noise. For a description of the various oscillator types see “The Oscillator section”


    Selecting oscillator type.


    With a basic connection setup, the Oscillator outputs are internally connected to the “Mix” section. To pass the output signal onwards in the signal chain, you first have to activate a connection. This is done using the two vertical rows of routing buttons labelled 1, 2 and 3 to the right of the Oscillator section.

    • The upper row of routing buttons determine which of the Oscillators 1 to 3 are routed to Filter 1, and the lower row which of the Oscillators 1 to 3 are routed to Filter 2

      All three oscillators can be simultaneously routed to both filters, serially or in parallel (or any combination of these variations). This is explained later in this tutorial.

      By activating one or more of these buttons means that the oscillator (1 to 3) is routed to the corresponding Filter. Currently, Oscillator 1 is connected to Filter 1 slot (which is pre-loaded with a Low Pass Ladder filter).

      This is indicated by the “1” routing button being lit. The Filter 2 slot is currently not active, which is indicated by a blank panel.

  5. Tap the “2” button to the left of the Filter 1 section so that it lights up to activate a connection for Oscillator 2.

    Now if you play a few notes you should hear both Oscillator 1 and Oscillator 2, via the Filter 1 section.

    • The Filter 1 output passes via the Shaper (currently not activated), on to the Amp section, and finally to the Main Outputs.

      Actually, the Amp section output is routed via the Global section before being sent to the Main Outputs, but as currently nothing is activated in the Global section the signal passes through unprocessed.

  6. Next, tap the arrow in the upper left corner of the Filter 2 slot.

    A list with the four available Filter types appears. For a description of the filter types, see “Filter slots”

  7. Select a type of filter, e.g. a Comb filter for the Filter 2 slot.

    Now that the Filter 2 slot in the Voice section is active, you can connect the oscillators to it by using the lower row of routing buttons.

  8. Tap the routing buttons “1” and “2” to the left of the Filter 2 slot so that the buttons are lit.

    Now the two oscillators are connected to Filter 2.

  9. Make sure the arrow routing button that points to the Amp section just above the Filter 2 section is activated.

    Now if you play a few notes, both oscillators are routed via both filter sections in parallel. You could of course select to pass only one of the oscillators via one filter and both oscillators via the other - any combination is possible.


    You can also connect the Filter 1 and 2 sections serially, meaning that the output of Filter 1 is passed through Filter 2 before reaching the Amp section. This is done as follows:

  10. Switch off the routing buttons “1” and “2” to the left of the Filter 2 slot.

    If you leave them on the oscillators will pass through Filter 2 twice; both via Filter 1 and directly. This is also perfectly “allowable”, but to make things clearer in this tutorial we will use a standard serial filter setup.

  11. Tap the left arrow button below the Shaper.

    Now the filters are connected serially, with the output of Filter 1 (via the for now inactive Shaper) being connected to the Filter 2 input. Both oscillators are processed by both filters connected in series.

That concludes this tutorial on how the pre-wired connections in the Voice section can be used, but note that you can also use the Modulation Bus to make connections - see “Modulation Bus routing section”.

Other pre-defined routing assignments

There are other sections in Thor which are pre-defined and can be used without having to make any prior assignments:

The Oscillator section

Oscillators generate the basic raw sound (pitch and waveform) that can in turn be processed by the other parameters. The Oscillator section contains three open slots which can each be loaded with one of six oscillator types. The three Oscillator slots are numbered 1-3, with the top slot housing Oscillator 1, the middle slot Oscillator 2 and the bottom slot Oscillator 3.

There are six Oscillator types available:

Common parameters

The specific parameters of the various oscillator types are described separately, but there are also common parameters that apply to all oscillator types. These are:

Analog Oscillator

This is a classic analog oscillator with 4 standard waveforms. The waveform selector button is in the lower left corner of the oscillator panel, but you can also tap directly on the waveform LEDs to switch waveform. The four available waveforms are from the top down (as displayed on the panel): Sawtooth, Pulse, Triangle and Sine.

Wavetable Oscillator

Wavetable oscillators has been the basis of several vintage synths (PPG, Korg Wavestation and many others).

The parameters are as follows:

Some of the wavetables have waveforms that sequentially follow the harmonic series, i.e. each following waveform adds a harmonic. Others have waveform series that produce a sound similar to oscillator sync when swept, and other wavetables are simply mixed waveforms. The last 11 wavetables are based on wavetables used in the original PPG 2.3 synthesizer.

Phase Modulation Oscillator

The Phase Modulation oscillator is inspired by the Casio CZ series of synthesizers. Phase modulation is based on modulating the phase of digital waveforms to emulate common filter characteristics.

The following waveforms (sequentially from the first) are available as the First waveform:

The last three waveforms could be described “resonant”, as these originally were meant to simulate filter resonance. They didn’t really do this very accurately, but nevertheless constituted an important part of the sound.

The Second waveform has the same available waveforms except the last three, and it can also be bypassed (OFF) altogether. You can combine waveforms freely, except it is not possible to combine two “resonant” waveforms.

FM Pair Oscillator

As the name implies, this oscillator generates FM, where one oscillator (Carrier) is frequency modulated by a second oscillator (Modulator). Although very simple to use (unlike most hardware FM synths), this oscillator can produce a very wide range of FM sounds.

Thus, 2:2 is the same wave shape as 1:1 but one octave higher in pitch, 3:3 is the same wave shape as 2:2 but a fifth higher in pitch and so on.

Multi Oscillator

This versatile oscillator can simultaneously generate multiple detuned waveforms (of a set type) per voice. It is great for producing complex timbres e.g. to simulate cymbal or bell sounds, but can also generate a wide range of harmonic sounds.

Noise Oscillator

The Noise oscillator can not only produce white and colored noise, but can also be used either as a pitched oscillator or as a modulation source.

It has the following basic parameters:

Mode Description
Band In this mode, the Oscillator knob controls bandwidth. Turned fully clockwise, the oscillator produces pure noise. Turning the knob counter-clockwise gradually narrows the bandwidth until a pitch is produced. The pitch will track the keyboard normally if the keyboard (KBD) knob is set fully clockwise.
S/H S/H stands for “sample and hold”, which is a type of random generator. The Oscillator knob controls the rate of the sample and hold. With high Oscillator knob settings, it produces colored noise with a slightly “phased” sound quality. With lower rate settings you can use the oscillator as a modulation source like a LFO with random values. For example, if you modulate the pitch of another oscillator using S/H with a low Rate setting as the source, you will get stepped random modulation of the pitch.
Static As the name implies, this can generate the sound of static interference if you use low Oscillator settings. The Oscillator parameter controls Density, i.e. the amount of static. High Density settings generates noise.
Color This produces colored noise, which is basically noise where certain frequency areas are filtered, i.e. cutting or boosting certain frequency areas in the noise. The Oscillator knob controls Color. With a maximum Color setting you get white noise, and lower settings produces noise emphasizing lower frequencies.
White This produces pure white noise, where all frequencies have equal energy. There is no associated Oscillator parameter for White noise.

About Oscillator Sync

Oscillator sync is when one oscillator will restart the period of another oscillator, so that they will have the same base frequency. If you change or modulate the frequency of the synced oscillator you get the characteristic sound associated with oscillator sync.

A synced oscillator that resets the other oscillator(s) is called the master, and any synced oscillator that is reset by an other oscillator is called a slave. In Thor, oscillator 1 is the master, i.e. this controls the base pitch of the oscillators, and oscillators 2 and 3 are slaves.

About Amplitude Modulation (AM)

AM (Amplitude Modulation) is often referred to as ring modulation. AM works by multiplying two signals together.

Mixer section

The Mix section allows you to adjust the levels and the relative balance of the three oscillators.

Filter slots

Thor has three open Filter slots, two in the Voice section (which act per-voice) and one in the Global section which is global for all voices (see “Global Filter slot”).

The following general rules apply:

The pre-defined routings of the three oscillators into the Filter 1-2 sections is described in the “Basic connections - a tutorial” passage.

Common parameters

As with the open oscillator slots, there are certain parameters which are common for all filter types.

These are as follows:

Low Pass Ladder Filter

The Low Pass Ladder filter is a low-pass filter inspired by the famous voltage controlled filter patented by Dr. Robert Moog in 1965. The name originates from the ladder-like shape of the original transistor/capacitor circuit diagram.

The original filter also had certain non-linear characteristics which contributed to the warm, musical sound it is renowned for. These characteristics are faithfully reproduced in the Low Pass Ladder filter.

There is also a built-in shaper in the feedback (self-oscillation) loop. If self-oscillation is activated (see below), the shaper will distort the sound to produce these non-linear characteristics. To adjust the intensity of this distortion you use the Drive parameter.

Note that “Self Osc” (see below) must be activated for the shaper to operate.

State Variable Filter

This is a multi-mode filter which offers 12 dB/octave slope Lowpass (LP), Bandpass (BP), Highpass (HP), plus Notch and Peak filter modes which are sweepable between HP/LP states, similar to the vintage Oberheim SEM filter.

The filter modes are as follows:

Comb Filter

The Comb filter can add subtle pitch variations and phasing-like effects to sounds.

Formant Filter

The Formant filter type can produce vowel sounds. There are no Frequency or Resonance parameters, instead you have a horizontal “X” parameter and a vertical “Y” parameter that operate together to produce the various filter formant characteristics.

Shaper

Waveshaping is a synthesis method for transforming sounds by altering the waveform shape, thereby introducing various types of distortion. The Shaper can radically transform the sound or just add a little warmth, depending on the mode and other settings.

Amp section

The Amp (amplifier) section has two inputs (from Filter 1 & 2) and one output which is routed to the Global section (and on to the Master Level and the Main Outputs).

LFO 1

An LFO (Low Frequency Oscillator) is used for generating cyclic modulation. A typical example is to have an LFO modulate the pitch of an oscillator to produce vibrato, but there are countless other applications for LFOs.

The following parameters are available for LFO 1:

Parameter Description
Rate This sets the frequency or rate of the LFO.
Waveform This sets the LFO waveform. Apart from standard waveforms (sine, square etc.) there are various different random, non-linear and stepped waveforms. The shape of the waveforms are shown in the display, and these shapes basically reflect how a signal is affected.
Delay This introduces a delay before the LFO modulation onset after a note is played. Turn clockwise for longer delay.
KBD Follow This determines if (or how much) the Rate parameter is affected by note pitch. If you turn the knob clockwise, the modulation rate will increase the higher up on the keyboard you play.
Key Sync As explained previously, LFO 1 is polyphonic and will produce a separate LFO cycle for each note played. If Key Sync is off, the cycles are free running, meaning that when you play a note the modulation may start anywhere in the LFO waveform cycle. If Key Sync is on, the LFO cycles are reset for each note played.
Tempo sync If this is on, the Rate will be synced to the main tempo (see “The Settings menu”).

Envelope sections

There are three Envelope generators in the Voice section. These are the Amp envelope, the Filter envelope and the Mod envelope. Each voice played has a separate envelope. There is also an additional Global Envelope which is described separately - see “Global Envelope”.

Filter Envelope

The Filter Envelope is a standard ADSR envelope generator.

Amp Envelope

The Amp Envelope is also a standard ADSR envelope.

Mod Envelope

This is a general purpose ADR (Attack, Decay, Release) envelope with a pre-delay stage before the Attack phase. The Delay to Decay phase can also be looped. Apart from standard Attack, Decay and Release stages the Mod Env has the following parameters:

Parameter Description
Delay This can set a delay before the onset of the envelope.
Loop If this is activated, the envelope phase from Delay to Decay will continuously loop.
Tempo Sync If this is on, each stage will have a length that corresponds to beat increments of the current tempo (see “The Settings menu”). E.g. you can have a 1/4 delay before a 1/16 attack phase followed by a 1/8 decay. Each stage can be set a range from 1/32 to 4/1 (4 bars).
If this is off, the envelope times are free running and can be set in seconds (same time ranges as for the Filter Envelope).
Gate Trigger The “Gate Trig” button can be used to switch off the envelope triggering from notes (which is the normal mode) and allow the envelope to be triggered by some other parameter. “Gate Trig” should normally be activated.

Global section

The Global section contains parameters that affect all voices as a group. It contains two effects, an open filter slot, the Global Envelope and LFO 2.

Effects section

There are two global mono in/stereo out effects, a Delay and a Chorus. These effects affect all voices coming from the Amp section equally if activated. The effects are placed after the Global Filter in the signal chain.

Global Filter slot

This is the Filter 3 slot which can be loaded with one of the filter types. Filter 3 is basically set up as the other filter slots. The difference is that all voices are mixed together before entering the filter. The “ENV” parameter governs modulation by the Global Envelope. If you play one note the filter envelope will trigger. Adding new notes while a note is still held down (legato) will not trigger the filter envelope.

See “Filter slots” for a description of the filter types.

Global Envelope

The Global Envelope 4 is an advanced envelope that is free to use for whatever purpose, but remember it is “single trigger” so it will not retrigger legato notes as explained above. It is an ADSR envelope with a pre-delay stage and a hold stage before the decay phase. You can make it Loop and Sync the time settings to the song tempo.

Apart from standard ADSR parameters, the Global Envelope has the following parameters:

Parameter Description
Delay This can set a delay before the onset of the envelope.
Loop If this is activated, the envelope phase from Delay to Decay will continuously loop.
Hold This allows you to set a “hold” phase before the Decay.
Tempo Sync If this is on, each stage will have a length that corresponds to beat increments of the current tempo (see “The Settings menu”). E.g. you can have a 1/4 delay before a 1/16 attack phase followed by a 1/8 decay. Each stage can be set a range from 1/32 to 4/1 (4 bars).
If this is off, the envelope times are free running and can be set in seconds (same time ranges as for the Filter Envelope).
Gate Trigger The “Gate Trig” button can be used to switch off the envelope triggering from notes and allow the envelope to be triggered by some other parameter. This button is normally activated.

LFO 2

The following parameters are available for LFO 2:

Parameter Description
Rate This sets the frequency or rate of the LFO.
Waveform This sets the LFO waveform. Apart from standard waveforms (sine, square etc.) there are various different random, non-linear and stepped waveforms. The basic shape of the waveforms are shown in the display, and illustrate how a signal is affected.
Delay This introduces a delay before the LFO modulation onset after a note is played. Turn clockwise for longer delay.
Key Sync If Key Sync is off, the LFO cycle is free running, meaning that when you play a note the modulation may start anywhere in the LFO waveform cycle. If Key Sync is on, the LFO cycle is reset for each note played.
Tempo sync If this is on, the Rate will be synced to the main tempo (see “The Settings menu”) in beat increments (4/1 to 1/32).