1 About

2 Table of Contents

3 Features

• arbitrary number of instrument tracks
  • arbitrary number of lanes per track
  • alternative MPE, lane-per-channel (LPC), voice-round-robin (VRR), drum pad sampler (drum kit) modes
  • side chain inputs
  • mid / side processing
  • routing between lanes, tracks and outputs
    • arbitrary number of outputs per track and lane
  • track mod matrix
    • for modulating module parameters via MIDI
    • cubic bezier curve note velocity, pitchbend, pressure, and CC / RPN / NRPN controller shaping
    • note and velocity range filters
    • continuous controller filters
      
• built-in lane modules
  • sampler
  • delay
  • gain / pan / stereowidth
  • 3-band equalizer
  • mid / side conversion
  • (cross-track) sync (+- 100ms)
  • Audio to MIDI RPN
  • MIDI RPN to Audio
  • Idle detection
  • CLAP plugin
  • VST2 plugin
  • STFX plugin
    
• sampler
  • arbitrary number of instances
  • arbitrary number of samples
    • stored as .wav + .esa files
    • (optional) YAML export for Rossum-Electro Assimil8or eurorack sampler
      • set b_write_yml_project = true; to enable this (see eureka_config.tks)
  • up to 32 sample namespaces
    • e.g. for separating audio clips and drum kits from regular samples
  • seamless sample switching
    • via MIDI program change or RPN
  • extensive (per voice) mod matrix
    • up to 16 entries per voice
    • 181 sources
    • 202 destinations
    • log / lin / exp curve per entry
    • slew per entry
    • 4 scratch registers
    • 13 op modes per entry (add, mul, replace, blend, compare, step, ..)
    • support for 14 bit hi-res continuous controllers (CCs)
      • modwheel (CC#1), breath control (CC#2), foot control (CC#4), expression (CC#11)
  • arbitrary number of zones (layers) per sample
    • mono or stereo
    • note, velocity, modulation (e.g. modwheel) filters
    • "alt" groups
    • "mutex" groups
  • up to 32 voice buses
    • for routing audio between sample zones
    • sample zone cross modulation (RM, AM, FM, ..)
  • arbitrary number of sample loops per zone
    • pitch or time based number of repeats
    • oneshot, forward, backward, pingpong, xfade loop modes
    • loops can be selected and switched via MIDI and mod matrix
  • monophonic and polyphonic glide
    • time or pitch based
    • separate up / down settings
    • sample / envelope / LFO / modseq legato retrig settings
  • 1D / 2D wavetables
    • static cycle length (2..4096 frames)
    • dynamic, pitch-dependent cycle length ("lo-fi timestretch")
  • additive (re-)synthesis
    • up to 256 partials
    • configurable stereo spread
    • up to 8 realtime-interpolatable resynthesis parameter sets
    • partial bit and sample rate reduction
    • conversion to regular wavetables (export to sample clipboard)
  • 4x3 ASR cubic bezier envelopes per voice
    • modulatable attack / decay+sustain / release speeds and levels
    • loopable sustain section
  • 4 LFOs per voice
    • sine / saw up+down / triangle / pulse / noise shapes
    • configurable start phase (fixed or random)
    • delay and fade-in
    • oneshot and loop modes
    • global or per-voice
  • 4 mod sequencers per voice
    • oneshot and loop modes
    • slew
    • forward, backward, pingpong, random, random(no repeat) play modes
    • time, note on, note off, mod rise / fall / edge / zcross step modes
    • up to 16 patterns, selectable via MIDI / mod matrix
  • MIDI or threshold triggered sampling
    • polyphonization of monophonic (oscillator) sound sources
      • update rate is ~300Hz
  • sample start and loop point modulation
    • random, velocity-based, and / or mod matrix controlled
  • voice calibration tables
    • for (subtle) voice modulation
    • up to 6 lanes
  • per-voice plugins
    • free and open source STFX plugin format
    • filters, waveshapers, ring-modulation, distortion, oscillators, ..
    • sample FM (sample read-rate modulation, SR plugin destination)
    • sample AM (amplitude modulation, AM plugin destination)
    • envelopes / modulation (VM1..VM8 plugin destinations)
  • Cycle software modular
    • "offline" sample synthesis
    • can also generate native code / realtime STFX voice plugins
      
• sample editor
  • cut / copy / paste / trim / fade-in+out / crossfade / invert / reverse / normalize / declick / ..
  • high quality resampling and other effects via SoX
  • time stretching / pitch shifting via Rubberband
  • undo / redo
  • snap to zero crossings or quarter notes (BPM based)
  • automatic region detection
  • automatic pitch detection
  • automatic loop point detection
  • .wav, .8svx, .aiff, .aiffc, .au, .caf, .cdda, .cdr, .flac, .ogg, .opus, .sds, .txw, .voc, .w64 import
    
• sample import from field recorders
  • audition sample (regions) via keyboard or MIDI
    • oneshot or loop playback
  • copy selected samples to local folder
  • tested with Zoom H4n pro and Tascam DR-05x
    
• instrument and effect plugin host
  • CLAP (Windows, macOS, Linux(todo: editor UIs))
  • VST2 (Windows, macOS, Linux(todo: editor UIs))
  • STFX (Windows, macOS, Linux)
  • plugin browser(s)
  • patch browser(s)
    • import / export .clp (CLAP)
    • import / export .fxp / .fxb (VST2)
  • generic parameter editors with filterable parameter selection
    • in addition to plugin editor UIs
  • up to 32 MIDI-controllable parameter sets per module instance
    • abs and smooth interpolation modes
    • up to 5 parameter set groups per track
      
• multi-core rendering
  • automatic or explicit track CPU core assignment
    
• multi-track stem recording
  • .wav export
  • recorded audio (regions) can immediately be played via MIDI
    • "live capture" mode: record+autotrim incoming audio
  • various options for creating new multi-samples from recorded audio
    
• (not released, yet): stand-alone player library
  • up to 256 tracks
  • supports (almost) every sampler feature
  • supports procedural samples (Cycle)
  • supports (custom) STFX voice and track plugins
    
    

4 Prerequisites

• a PC running Windows 10 or higher
• or a PC or other computer running Linux (e.g Debian 12)
• or a Mac running macOS 10.12+ (x64) or 13.x+ (arm64)
• an audio interface capable of low-latency I/O (required on Windows, recommended on macOS)
  

• Synergy sequencer
  

5 Installation

1. install Synergy
2. open the "stop button" menu and select Start "Eureka" audio host.. to launch the application
3. in Eureka, open the preferences dialog (Prefs.. button), and configure the audio device, sample rate, paths, .. as required.
   • The settings will be saved to eureka_config_local.tks when the preferences dialog is closed.
     
     

5.1 MIDI loopback (deprecated)

1. install MIDI loopback device driver (e.g. loopMIDI on Windows), or use the built-in IAC driver on macOS
2. add two loopback devices named remote_audio and remote_seq
3. add four loopback devices named vst_a, vst_b, vst_c, vst_d (optional: also add vst_e..vst_h)
4. set b_enable_localmidi = false; in both synergy_config.tks and eureka_config.tks
   

5.2 Optional

1. open eureka_config.tks in a text editor
2. adjust b_minimal_startup variable (false=enable VST/voiceplugin/samplecache scans)
3. adjust rootpath variable
4. adjust audiotrack_wav_rootpath variable
5. adjust exported_samples_wav_rootpath variable
6. adjust project_samples_wav_rootpath variable
7. adjust sample_rootpath variable
8. adjust b_force_single_thread variable (set to false to enable multicore rendering (default on macOS))
9. adjust clap_paths / vst_paths variables
10. adjust atrk_rec_skip_num_frames (latency compensation) as required (default=-80)
    

5.3 Audio input and output channel aliases

1. open eureka_config_local.tks in a text editor
2. edit the audio_in_aliases and / or audio_out_aliases arrays
   
   

6 UI

6.1 Windows and dialogs

• RMB-clicking a window title bar closes the window (e.g. the Scope or wave browser)
• LMB-clicking outside a popup-type dialog or pressing ESCAPE closes it (most other windows)
  

6.2 FloatParams

• vertical RMB-drag or cursor UP / DOWN coarse edits the value
• horizontal RMB-drag fine edits the value
• holding lshift before / while starting to drag increases the coarse / fine precision (ten-fold)
• holding lctrl snaps to integers
• LMB-click during RMB-drag reverts the value (same with sliders and dials)
• mouse WHEEL up / down increments / decrements the value in coarse steps
• lshift WHEEL or cursor UP / DOWN increments / decrements the value in fine steps
• LMB-hold-click or p shows the preset combobox popup (if there are any presets)
• LMB-double-click cycles through reset values
• RMB-click or SPACE shows FloatParam dialog (dial + range edit + reset)
  • note: some parameters have auto-extending ranges which can be reset here
• t / r scale the value by +-50%
• i / u double / halve the value
• n flips the sign
• h toggles hexadecimal mode
• m toggles mouse drag precision (float value decimal places, default=enabled)
  

6.3 Statusbar

• displays messages
• doubles as a command line for executing "page commands" (e.g. resize / allocate waveform on sample page)
  • lctrl-backtick (or ^) sets keyboard focus
  • RMB click shows presets commands (with default args)
  • UP shows history
  • DOWN shows presets
    

6.4 Tables

• MMB-click toggles between paging and row selection mousewheel scrolling mode
• a opens the context menu (if any)
• RMB-click previews the selected item or starts cell editing (when available)
• RMB-drag or lshift-LMB-click selects multiple items / range (when available) (lctrl click toggles item selection)
• SPACE or RETURN selects item (same as double-clicking row)
  
  

7 Keyboard Shortcuts

7.1 Global

7.2 "Audio" page

7.3 "Samples" page

7.4 "Project" page

7.5 "Track" page

7.6 Sample View

8 MIDI implementation

8.1 vst_a .. vst_z ports

• can be assigned to instrument tracks
• events will be forwarded to all lanes / modules matching the event's MIDI channel and module's mod matrix filter
  • in default track mode: sent to all track lane-modules
  • in LPC track mode: sent to the lane(-modules) matching the event's MIDI channel
    • "Lane Offset" determines which lane is mapped to MIDI channel #1
  • in MPE track mode: sent to the lane(-modules) matching the event's MIDI channel.
    • "Master channel" events (usually on MIDI channel #1) are sent to all MPE lanes
    • "Lane Offset" determines which lane is mapped to the first available MIDI channel (usually MIDI channel #2)
  • in drum pad sampler mode: sent to all track lane-modules. Notes will trigger the matching drum pad.
    • pitchbend and modwheel / breathctl / footctl / volume / balance / pan / expression / brightness / general 1..8 performance CCs (and All Notes Off CC) are forwarded to all pad sample players
    • MIDI notes C-3..G-3 (36..43) select the currently active drum kit variation
      
      

8.2 remote_audio port

• primarily used for receiving SysEx requests / replies from the "Synergy" sequencer process
  
• context-sensitive MIDI event routing
  • the current instrument track can be played via the remote_audio MIDI port (in addition to its main MIDI port vst_a..vst_h)
  • the current sample (on the sample page) can be played via the remote_audio MIDI port, unless the sample page was entered by clicking on a ModSample instance
  • the current audio track (on the start page) can be played via the remote_audio MIDI port
    
• can also be used for receiving direct module parameter changes (i.e. without track or sampler mod matrix mapping)
  • see "Remote" tracker instrument parameter type in "Synergy"
    

8.3 remote_seq port

• used for sending SysEx requests / replies to the "Synergy" sequencer process
  
  

8.4 Module specific MIDI events

8.4.1 Sampler

8.4.1.1 Start offset (audio clips)

8.4.1.2 Sample selection by unique id (UID)

8.4.1.3 Sample selection by namespace-local index

8.4.1.4 Performance controllers

• pitchbend, channel+poly pressure, and performance controller CC#1/CC#33 (modwheel), CC#2/CC#34 (breath control), CC#4/CC#36 (foot control), CC#11/CC#43 (expression pedal), CC#7(volume), CC#8(balance), CC#10(panorama), CC#16..CC#19 (general purpose 1..4), CC#74 (brightness), CC#80..CC#83 (general purpose 5..8) can be mapped in the sampler mod matrix
  • the performance CCs support 7bit (MSB) and 14bit (MSB+LSB) precision
• CC#64 (sustain pedal) sustains all pressed notes (when value is >= 64)
• CC#65 (portamento switch) allow glide when value is >= 64 (def=yes)
• CC#66 (sostenuto pedal) sustains only the currently pressed notes (when value is >= 64)
• CC#121 (controller reset) resets all performance controllers
• CC#127 (all notes off) stops all voices
  
  

8.4.2 CLAP, VST2 and STFX plugins

8.4.2.1 Mod Matrix

8.4.2.2 Param Sets

• RPN_PARAMSET_1..5 (70..74) select a parameter set for group 1..5 (without interpolation)
  • value range is 1..32
• RPN_PARAMSET_SMOOTH_1..5 (75..79) select a parameter set for group 1..5 (with interpolation)
  • value range is 0..16383
  • 512 fractional steps between two parameter sets
  • values 15872..16383 interpolate between parameter sets 32 and 1
    
    
    

8.5 Track / Lane Fading RPNs and CC

9 Files and Directories

9.1 Project

mProjects/eureka_data/projects/test.epr 
mProjects/eureka_data/projects/test/ 
mProjects/eureka_data/projects/test/samples/ 
mProjects/eureka_data/projects/test/tracks/ 
mProjects/eureka_data/projects/test/exported_samples/ 

9.1.1 samples

samples/mysample.esa 
samples/mysample.wav 

9.1.2 tracks

9.1.3 exported_samples

9.2 Library

9.2.1 Samples

mProjects/samples/ 

9.2.1.1 User Samples

mProjects/samples/bsp/ 
mProjects/samples/bsp/drumkit/ 

9.2.1.1.1 Drum Kits

mProjects/samples/bsp/drumkit/808_95.edk 
mProjects/samples/bsp/drumkit/808_95_bd.esa 
mProjects/samples/bsp/drumkit/808_95_bd.wav 
mProjects/samples/bsp/drumkit/808_95_ch.esa 
mProjects/samples/bsp/drumkit/808_95_ch.wav 
mProjects/samples/bsp/drumkit/808_95_sd.esa 
mProjects/samples/bsp/drumkit/808_95_sd.wav 

9.2.2 Track patches

mProjects/eureka_data/patches/ 

9.2.3 CLAP plugins

9.2.3.1 Plugin Paths

9.2.3.2 Patches

mProjects/eureka_data/clap_patches/ 

9.2.4 VST plugins

9.2.4.1 Plugin Paths

9.2.4.2 FXP / FXB Patches

mProjects/eureka_data/vst_patches/ 

9.2.5 STFX plugins

9.2.5.1 Patches

mProjects/eureka_data/stfx_patches/ 

10 Pages

10.1 Audio page

• used to manage an arbitrary number of mono or stereo audio tracks
  • scratch pads
  • stems
    
• audio tracks can record..
  • the incoming audio of a specific interface channel (pair) (Audio In mode)
  • the outgoing audio of a specific interface channel (pair) (Audio Out mode)
  • the outgoing audio of a specific track (Track mode)
    
• recording (for all armed tracks) starts..
  • when an MMC record-start message is received from the sequencer
    • e.g. by starting the replay via lshift - (np) ENTER
  • or when the record button in the lower right window corner is pressed
    
• the sample view below the audio tracks list displays the currently selected track
  • the track selection is changed via PAGEUP / PAGEDOWN keys, mousewheel, or by clicking on a track
    
• audio track (preview) replay is done via the 'scratch' sample player (routed directly to the main outputs)
  • the widgets below the sample editor configure the basic replay settings, i.e.
    • velocity-to-volume amount
    • release curve (Gate, Short, Medium, Long, Infinite)
    • volume ramping
    • loop switch
    • polyphony
    • sample start offset
    • sample start offset randomization
    • pan position randomization
      
• the Live Capture mode is used for "hands-free", threshold-level based autosampling
  • sampling starts when the selected input exceeds the silence threshold
    • and stops when the input goes back to silence
    • the recorded sample can immediately be played afterwards
  • for example, with two MIDI keyboards:
    • route one to a monophonic synthesizer (or use the synthesizer's keyboard if it has one)
    • route the audio output of the synthesizer to the audio track
    • route the second MIDI keyboard to the remote_audio MIDI port of the sampler
    • each time the synth patch has changed, press and release a key on the synth, then play the auto-recorded sample polyphonically
      
• new (multi-)samples can be created via the Create.. popup menu
  

10.2 Tracks page

• cursor keys or mousewheel change the track focus
  • MIDI events received on the (virtual) remote_audio port are redirected to the focused track
    
• to edit an instrument track, right-click the track's title bar, press the e key, or click the Edit button (when visible)
  
• the first sampler or CLAP / VST2 plugin instance of an instrument track can be edited by middle-clicking the track's title bar
  
• if a track named master exists, a new track's audio output will be auto-routed to it
  
• tracks are reordered by drag'n'dropping a track onto another track (upper half = before, lower half = after).
  

10.3 Current Track page

• a track consists of n lanes, and each lane consists of m modules, which are processed in the order of occurence.
  • the output of a track can be routed to other tracks, or audio interface outputs.
    • when it is set to Default, the output is routed to the main output (interface channels 1 + 2)
    • each track may have an arbitrary number of outputs
  • the output of a lane can be routed to other lanes, tracks, or audio interface outputs.
    • when it is set to Default, the output is routed to the track output(s)
    • each lane may have an arbitrary number of outputs
  • each track, and each lane, has 4 audio inputs:
    • left
    • right
    • side chain left
    • side chain right
  • each module has a mod matrix which is used to map MIDI events to module parameters
    • this is not to be confused with the ModSample sample zone mod matrix (which is saved in the sample)
    • cubic bezier modulation curves can be employed to create non-linear parameter modulation
    • the module mod matrix can be queried from the sequencer, e.g. when importing parameters into a CtlMorph or Tracker node
    • a new mod matrix entry for the last touched (CLAP / VST2) parameter can quickly be added by pressing the F12 key
    • the mod matrix view will initially display the last highlighted lane module (mouse over)
  • each module also has a MIDI input filter which can restrict the note and velocity ranges, filter out continuous controller (CC), pitchbend, and (poly-)pressure events, and transpose incoming notes
    
• a new ModSample instance is created by right clicking on an empty lane mod slot and choosing Builtin→Sampler
  
• cursor left / right or mousewheel selects the previous / next track
  
• hold-clicking the background navigates to the parent page (usually the Tracks page)
  • on the project and tracks pages, double-clicking accomplishes the same thing
    

10.3.1 Track modes

• in general:
  • a modules' MIDI input filter can be used to filter out events, restrict the module to certain note ranges, transpose notes, and apply note-on / note-off velocity curves
    

10.3.1.1 Default

• incoming MIDI is routed to all lanes / modules
  

10.3.1.2 Lane Per Channel (LPC)

• for this mode, the MIDI channel selection should be set to *
  
• each MIDI channel is routed to a different lane
  • the lane offset setting determines which lane is mapped to MIDI channel #1
  • the lane number setting determines the number of MIDI channels
    • lanes beyond that may be used for FX processing
      

10.3.1.3 Mirror Lane Per Channel (MLPC)

• same as LPC except that (CLAP / VST2) parameter edits are automatically mirrored to all other-lane modules in the same grid y position
  

10.3.1.4 MIDI Polyphonic Expression (MPE)

• for this mode, the MIDI channel selection should be set to *
  
• each MIDI channel is routed to a different lane
  • MIDI events on MIDI channel #1 (master channel) are routed to all lanes
  • the lane offset setting determines which lane is mapped to MIDI channel #2
  • the lane number setting determines the number of number of MIDI channels (e.g. 6 = #2..#7)
    • lanes beyond that may be used for FX processing
      

10.3.1.5 Mirror MIDI Polyphonic Expression (MMPE)

• same as MPE except that (CLAP / VST2) parameter edits are automatically mirrored to all other-lane modules in the same grid y position
  

10.3.1.6 Voice Round Robin (VRR)

• the lanes are cycled at each note-on
  • the lane offset setting determines which lane is mapped to the first note
  • the lane number setting determines when to cycle back to the first (<lane offset>) lane
    • lanes beyond that may be used for FX processing
      

10.3.1.7 Mirror Voice Round Robin (MVRR)

• same as VRR except that (CLAP / VST2) parameter edits are automatically mirrored to all other-lane modules in the same grid y position
  

10.3.1.8 Drum Pad Sampler (Drum)

• supports up to 32 drum pads and up to 8 variations
  • pads are played via MIDI notes C-4 .. B-5 (bank A) and C-6 .. B-7 (bank B)
  • variations are selected via MIDI notes C-3 .. G-3
    
• incoming MIDI events are routed to all pads and lanes / modules
  
• each pad can be assigned a sample
  • either by selecting an existing one
  • or by drag'n'dropping a .wav file or .esa sampler patch onto the pad
    
• pads can be linked so that a single note plays multiple sounds
  • up to 8 link groups (a..h)
    
• pads can be mutually exclusive so that e.g. a closed hihat cuts off an open hihat sound
  • up to 8 mutex groups (A..H)
    
• the audio output of each pad's sample player can be sent to up to 8 lanes
  

10.3.1.8.1 Drum Pad Layouts

• 8x2
  • Bank A:

       Pad Layout 8x2 A 
        
       +-------+-------+-------+-------+-------+-------+-------+-------+ 
       |  BD1  |  SD1  |  CP1  |  LT1  |  MT1  |  HT1  |  CH1  |  OH1  | 
       +-------+-------+-------+-------+-------+-------+-------+-------+ 
       |  BD2  |  SD2  |  CP2  |  MA1  |  CL1  |  CB1  |  RS1  |  CY1  | 
       +-------+-------+-------+-------+-------+-------+-------+-------+ 
        = 
       +-------+-------+-------+-------+-------+-------+-------+-------+ 
       |  C-4  |  D-4  |  E-4  |  F-4  |  G-4  |  A-4  |  A#4  |  B-4  | 
       +-------+-------+-------+-------+-------+-------+-------+-------+ 
       |  C-5  |  D-5  |  E-5  |  F-5  |  G-5  |  A-5  |  A#5  |  B-5  | 
       +-------+-------+-------+-------+-------+-------+-------+-------+ 

  • Bank B:

       Pad Layout 8x2 B 
        
       +-------+-------+-------+-------+-------+-------+-------+-------+ 
       |  BT1  | ZAP1  |  FX1  | COPEN | CMUFF | CSLAP |NOISE_S|NOISE_L| 
       +-------+-------+-------+-------+-------+-------+-------+-------+ 
       |  BT2  | ZAP2  |  FX2  |  MA2  |  CL2  |  CB2  |  RS2  |  CY2  | 
       +-------+-------+-------+-------+-------+-------+-------+-------+ 
        = 
       +-------+-------+-------+-------+-------+-------+-------+-------+ 
       |  C-6  |  D-6  |  E-6  |  F-6  |  G-6  |  A-6  |  A#6  |  B-6  | 
       +-------+-------+-------+-------+-------+-------+-------+-------+ 
       |  C-7  |  D-7  |  E-7  |  F-7  |  G-7  |  A-7  |  A#7  |  B-7  | 
       +-------+-------+-------+-------+-------+-------+-------+-------+ 

    e.g. DSI Tempest or Novation SL mk3
• 4x4
  • Bank A:

    Pad Layout 4x4 A 
     
    +--------+--------+--------+--------+   +-----+-----+-----+-----+ 
    |   RS   |   CH   |   OH   |   CY   |   | A#5 | A#4 | B-4 | B-5 | 
    +--------+--------+--------+--------+   +-----+-----+-----+-----+ 
    |   LT   |   MT   |   HT   |   CB   |   | F-4 | G-4 | A-4 | A-5 | 
    +--------+--------+--------+--------+ = +-----+-----+-----+-----+ 
    | BDSHRT | SDSHRT | CPSHRT |   CL   |   | C-4 | D-4 | E-4 | G-5 | 
    +--------+--------+--------+--------+   +-----+-----+-----+-----+ 
    | BDLONG | SDLONG | CPLONG |   MA   |   | C-5 | D-5 | E-5 | F-5 | 
    +--------+--------+--------+--------+   +-----+-----+-----+-----+ 

  • Bank B:

    Pad Layout 4x4 B 
     
    +--------+--------+--------+--------+   +-----+-----+-----+-----+ 
    |  RS2   |NOISESRT|NOISELNG|  CY2   |   | A#7 | A#6 | B-6 | B-7 | 
    +--------+--------+--------+--------+   +-----+-----+-----+-----+ 
    | C_OPEN | C_MUFF | C_SLAP |  CB2   |   | F-6 | G-6 | A-6 | A-7 | 
    +--------+--------+--------+--------+ = +-----+-----+-----+-----+ 
    |  BT1   |  ZAP1  |  FX1   |  CL2   |   | C-6 | D-6 | E-6 | G-7 | 
    +--------+--------+--------+--------+   +-----+-----+-----+-----+ 
    |  BT2   |  ZAP2  |  FX2   |  MA2   |   | C-7 | D-7 | E-7 | F-7 | 
    +--------+--------+--------+--------+   +-----+-----+-----+-----+ 

    e.g. Akai MPK49
• 4x3
  • Bank A:

    Pad Layout 4x3 A 
     
    +--------+--------+--------+--------+   +-----+-----+-----+-----+ 
    |   CH   |   OH   |   CY   |   CB   |   | A#4 | B-4 | B-5 | A-5 | 
    +--------+--------+--------+--------+   +-----+-----+-----+-----+ 
    |   BT   |   LT   |   MT   |   HT   | = | C-6 | F-4 | G-4 | A-4 | 
    +--------+--------+--------+--------+   +-----+-----+-----+-----+ 
    |   BD   |   SD   |   RS   |   CP   |   | C-4 | D-4 | A#5 | E-4 | 
    +--------+--------+--------+--------+   +-----+-----+-----+-----+ 

    e.g. Elektron Analog Rytm
• 4x2
  • Bank A:

    Pad Layout 4x2 A 
     
    +-------+-------+-------+-------+   +-----+-----+-----+-----+ 
    |  BD1  |  SD1  |  CP1  |  CH   | = | C-4 | D-4 | E-4 | A#4 | 
    +-------+-------+-------+-------+   +-----+-----+-----+-----+ 
    |  LT1  |  MT1  |  HT1  |  OH   |   | F-4 | G-4 | A-4 | B-4 | 
    +-------+-------+-------+-------+   +-----+-----+-----+-----+ 

  • Bank B:

    Pad Layout 4x2 B 
     
    +-------+-------+-------+-------+   +-----+-----+-----+-----+ 
    |  BD2  |  SD2  |  CP2  |  RS   |   | C-5 | D-5 | E-5 | A#5 | 
    +-------+-------+-------+-------+   +-----+-----+-----+-----+ 
    |  MA1  |  CL1  |  CB1  |  CY   | = | F-5 | G-5 | A-5 | B-5 | 
    +-------+-------+-------+-------+   +-----+-----+-----+-----+ 

    e.g. Akai MPK mini
    
    

10.3.1.8.1.1 Drum kit pad indices, MIDI notes, short and long names

10.3.2 Plugins

• plugins are instanced by drag'n'dropping them from the plugin browser
  
• plugin patches named init will be auto-loaded after plugin instantiation
  • init_delay will be loaded when the plugin filter is set to "delay", init_reverb when it is set to "reverb", and so on
    
• plugins instances are deleted by drag'n'dropping them back to the plugin browser
  

10.4 Samples page

• each project may contain an arbitrary number of samples
  • a unique MIDI program number (1..128) can be assigned to each sample
  • alternatively, samples can be selected by their unique id (1…16384). see Sampler MIDI events.
    
• samples can be sorted into (up to 32) namespaces
  • namespaces are added, renamed, or deleted by hold-clicking a namespace combofield
    • renaming an empty slot will add a namespace
    • renaming a non-empty slot will rename the namespace
    • renaming a non-empty slot to "" will delete the namespace
      
• the way the Samples page is entered matters:
  • when the Samples page is entered by clicking the Samples page menu button (F1 or F5 key):
    • the sample will be played through a 'scratch' sample player that is routed to the main output (without effects)
    • the sample list will be filtered by the last selected sample namespace
  • when the Samples page is entered by clicking on a track's ModSample sampler instance:
    • the sample will be played through the track, its effects, and audio routings
    • the sample list will be filtered by the initially selected sample namespace
    • selecting a sample will change the sampler's sample selection
      • changing the sample's namespace will also update the track sampler's preferred namespace
    • keys 4 and 5 select the previous / next sampler instance of the parent track
      • alternatively, click the < and > buttons
        • clicking the track name button on the right shows the list of currently selected track samples
  • when the Samples page is entered by clicking on a drum pad (when the track is set to Drum mode):
    • the sample will be played through the track, its effects, and audio routings
    • the sample list will be filtered by the initially selected sample namespace
    • keys 4 and 5 select the previous / next (used) drum pad
      • alternatively, click the < and > buttons
        • clicking the drum pad name button on the right shows the list of currently selected drum pad samples
          
• keys 2 and 3 select the previous / next zone of the current sample. key 1 selects all zones.
  
• clicking on a sample once will select it, twice will select the first tabs (Patch and Loops), thrice will execute the default action for the first selected zone
  • the default action (no op, play zone, edit synth patch, edit synth patch machine) is changed by clicking the middle label button right below the zones list (-, P, S, M)
    
• the edit precision of an initial performance controller can be toggled by clicking the corresponding label (mw, bc, fc, ex, gp1..4)
  

10.4.1 Zones

• each sample may contain an arbitrary number of sample zones (layers)
  
• all sample zones share the same waveform
  • but not necessarily the same waveform area
  • each sample zone maintains the last seen sample editor view (scroll position + zoom)
    
• each zone may define an arbitrary number of loops
  • loops may not necessarily be actual loops but can also be used as oneshot sample regions
  • selecting a loop (in the loops table) sets the initial note-on loop
    • the R: widget sets the note-off loop
  • the Rep: setting defines the number of loop iterations before advancing to the next loop
    • setting this to 0 causes the loop to be played indefinitely
    • when the ms: option is checked, this value is interpreted as number of milliseconds instead (timed loops)
  • the Jump To Loop mod matrix targets can be used to change the currently playing loop
  • pressing lctrl-h (when the sample editor is focused) sets the currently edited loop to the selected area (Copy selection to highlight item in the sample editor context menu)
    
• other zone features include..
  • 4 global or per-voice LFOs with fade in, start-phase and oneshot options
  • 4 global or per-voice, loopable mod sequencers with oneshot option and up to 16 MIDI-switchable patterns
  • up to 6 voice calibration tables, e.g. for adding subtle variations or stereo spread
    • table 2 (pan) can also be applied to the partial stereo spread of additive wavetables
    • all tables are available as mod matrix sources
  • time or frequency domain (additive) wavetable modes
  • monophonic and polyphonic glide modes
    
• when multiple zones are selected, parameter edits will update all selected zones (multi-edit)
  
  

10.4.2 Live Recording

• the sample waveform can be recorded from incoming mono or stereo audio when the sample is selected in a track's ModSample sampler instance
  
• recording settings are located in the Rec tab and include..
  • input selection
    • left and / or right channel
    • side chain left / right channel
  • latency compensation
    • skip n sample frames at the start of a new recording
  • (default) target area
    • index into Loops table
  • recording mode
    • MIDI or manual trigger (Wait for trigger* modes)
    • threshold-level trigger (Wait for signal mode)
    • continuous (Continuous, Continuous Ring modes)
  • monitor mode
    • listen to incoming audio (Monitor checkbox) or a mix between the audio input and sampler output (Sum checkbox)
  • overdub mode
    • add recorded audio to existing waveform instead of replacing it (Init checkbox)
  • double buffer mode
    • when enabled (not set to -), splits the waveform into two equal halves
    • the sides (front-/backbuffer) are swapped..
      • in - mode: never
      • in End mode: when the last recording is finished
      • in Voice (Queue) mode: when the next voice or the next recording is started
      • in Rec Start mode: when the next recording is started
      • in Param mode: when receiving a LiveRec DblBuf Index parameter change message
  • copy mode
    • copies recordings to voice-internal buffers so the next recordings won't interfer with the playback of previous recordings
  • live-looped oscillator cycle detection mode
    • can be used to "polyphonize" monophonic sound sources, e.g. a modular system
    • the sound source must be a constant-pitch tone
    • the loop cycle is updated around 300 times per second
      • fast enough for manual modulation, LFOs, and (slow) envelopes
        
• recording can be controlled via the LiveRec Start, LiveRec Stop, LiveRec Continue modmatrix destinations
  • LiveRec Start starts the recording when the value exceeds 0.5 (i.e. 64 when the source is a MIDI CC)
  • LiveRec Stop stops the recording when the value exceeds 0.5 (i.e. 64 when the source is a MIDI CC)
  • LiveRec Continue continues the recording when the value exceeds 0.5 (i.e. 64 when the source is a MIDI CC)
    
• more fine-grained control is possible by sending parameter changes directly to the sampler instance
  • this can be used to change the recording region (target loop), explicitely select the front-/backbuffer area of a double buffered waveform, and start / stop / continue the recording for specific zones
    • parameter names: LiveRec Start Mask, LiveRec Continue Mask, LiveRec Stop Mask, LiveRec Target Loop Shift, LiveRec Start Index, LiveRec Continue Index, LiveRec Stop Index, LiveRec DblBuf Index
    • see Tracker node Remote instrument parameter type
      
• the Freeze button stops live recording and copies the last started voice recording buffer to the sample waveform
  
• the Capture Dialog is used for building wavetables (in the sample clipboard)
  • it becomes available when both live recording and Copy mode are enabled
  • the currently detected oscillator cycle will be resampled to the given cycle len and added to the sample clipboard
    

10.4.3 Voice Buses

• voice buses are used to route the output of a sample zone (layer) to other zones.
  voice buses are used in conjunction with voice plugins.
  
• each sample supports up to 32 voice buses
  • see Zone tab Bus: combobox
    
• zones that write to a voice bus must occur before zones that read from it
  

10.4.4 Voice Plugins

• on the FX tab, up to four plugins may be configured for each sample zone
  • voice plugins use the lightweight, free open source STFX plugin format
    
• voice plugins are instantiated per voice (hence the name)
  • effects like distortion, waveshaping or ring modulation sound quite different when applied to each voice separately instead of the polyphonic mix (like a VST plugin)
    
• the plugin processing order / routing can be configured using 24 algorithms plus the filter position
  • serial, parallel, ..
  • not selecting a particular algorithm results in the plugins being processed in linear order (1..4)
    
• the parameter configurations and routing can be saved as presets
  • FX tab P button opens preset browser
    
• voice plugins can access any of the 32 voice buses
  • by convention, the names of plugins which support this start with x, e.g. "x je ring modulator"
    
• Eureka currently ships with 154 open source plugins
  • many have been written from scratch
  • a few have been ported from VCV Rack
  • some have been auto-generated via Cycle
    

10.4.5 Procedural Samples

• procedural sample mode is activated by selecting Cycle in the Synth combobox (at the top of the window)
  • samples can be synthesized in 8 bit integer mode (with internal 11 bit fixed point precision + 4 bit headroom), or with 32 bit floating point precision
    • the integer mode can be interesting for "grungy", "LoFi" sounds
    • in ("HiFi") float mode, sections of a machine script may revert to integer mode via the int module
  • procedural sample generation "C" code can be exported for use in games or demos
    • integer mode supports classic 68k based CPUs (e.g. Amiga 500, Atari ST, ..) as well as modern CPUs
    • float mode supports modern CPUs (basically everything since the mid / late 90ies)
      
• unlike static samples, no waveforms (.wav files) will be saved for procedural samples. Merely the sample size and instructions for how to synthesize the sample will be stored in the .esa (sample patch) files (in the library and / or the project directory)
  
• each sample stores up to 32 patches which can target any of the sample's zones
  • the render area for a procedural sample (zone) is determined by the zone's last loop area
  • each patch is defined by a machine (the synth script), up to 16 cubic bezier curves (LUTs), and up to 32 parameters (args)
    • machines can be saved as presets
    • bezier curves are converted to lookup tables with user-defined precision
  • multiple patches may share the same machine (Share: combobox)
    • common args may be inherited from the shared machine
      • on a per parameter basis, see checkbox next to each each arg
  • the sample patches will be processed in the order they are defined (1..32)
    • it is recommended to order the zones accordingly
      • the zones table context menu has a utility function for aligning the patch order to the zone order (SampleSynth: Reorder patches by zones)
        
• procedural samples can either be entirely synthesized, or be created by processing other (static) sample zones
  • reading from other samples can be used to create precalculated variations of static samples
    • see zlp, zon, and zsq modules
  • any STFX voice plugin can be used in a procedural patch
    • see vpl module
    • parameters for the currently selected plugin can be copied to the clipboard (in single or multi-line Cycle format) via the FX tab context menu (or by pressing lctrl-c / lctrl-lshift-c when the FX tab has the keyboard focus)
    • new (polyphonic and realtime) STFX voice plugins can be generated from Cycle patches
      
• see example patches, plugins, and the Cycle manual for details
  

11 Projects

• Eureka projects will be saved when saving projects in Synergy (hold-clicking Save shows an emergency save dialog)
  
• to load a project, load a Synergy project, then click Load on the Eureka start page (hold-clicking Load shows a load dialog which you will most likely never need to use)