Remerciez-le!

Remerciez @Admin pour avoir partagé cet document gratuitement, de la manière la plus simple, en partageant sur les réseaux sociaux.

ACE Any Cable Everywhere (c) 2009 by Urs Heckmann, translated by Howard Scarr C

ACE Any Cable Everywhere (c) 2009 by Urs Heckmann, translated by Howard Scarr Contents A.C.E. 4 Concept and Features 5 Modular, ultrasonic 5 Analogue modeling 5 Layout and Signal Flow 6 Operation Settings 7 Stack 8 Glide 9 Oscilloscope 9 Pitch Controls 10 LFO 1 11 LFO 1 - Sample & Hold Mode 11 Using LFO 1 in Unconventional Ways 12 LFO 2 12 VCO - the Oscillators 13 Mixer 14 VCF - the Filters 14 Gain & Self-Oscillation 16 ADSR 16 Ramp Generator 17 Mapping Generator 18 Map modes 19 Edit functions 19 Multiples 20 Multiple as mixer 20 Multiple as ring modulator (RM) 20 Multiple as amplitude modulator (AM) 21 Multiple as balance controller 21 VCA and Eects 22 Chorus 23 Delay 24 EQ 25 Other Signal Sources 25 User Interface 26 Knobs 26 Menu Switches 27 Cables 27 Patch Management 28 In the synth page 28 In the patch page 29 Via MIDI 29 Other Patch Manager Functions 30 Undo/Redo 30 A.C.E. Does the world really need another simple synthesizer? We believe it does - but there's a lot more to ACE than meets the eye... The software synthesizer ACE (Any Cable Everywhere) delivers top quality sound at a highly competitive price. The selection of modules and clear layout make ACE the ideal instrument for newcomers delving into the fascinating world of modular synthesis. The number of ways to connect modules together is practically inﬁnite, and you will soon discover how much more fun it is to make your own sounds in ACE than in a non-modular synthesizer. Concept and Features Modular, ultrasonic Most digital synths handle audio signals and modulation signals dierently. Audio signals are normally evaluated at a sample rate between 44100 and 96000 Hertz, while modulation signals have to make do with 1000 Hz or even less (often called the "control rate" of the synthesizer). ACE is very dierent in this respect. While the oscillators feature more than 500 times oversampling, all signals - including modulation - run at least twice as fast as the host application's sample rate. And this is only the lowest of ACE's quality settings! ACE does not dierentiate between audio signals and modulation/control signals at all. Any Cable Everywhere - you can plug any of the 24 signal outputs into any of the 30+ signal inputs and expect it to work just like a vintage modular hardware synth. The sky is NOT the limit - all modulation can work beyond the limits of human hearing. For instance, the LFOs (Low Frequency Oscillators) can be set above 20 kHz, and still modulate e.g. the pulse width of an oscillator. This gives you a sonic freedom previously reserved for expensive analogue hardware. Either or both LFOs can be used as audio oscillators in their own right (e.g. for crystal-clear FM sounds). Conversely, the VCOs can be used as alternative LFOs, i.e. they can be set as low as 0.00 (zero) Hz. Note: DC components are quickly removed from the VCO outputs, so their shapes when used as LFOs might not be as you would expect. Analogue modeling To make this work, not only do the modules resemble their analogue counterparts, but their components do as well. Wherever necessary, the non- linear characteristics of analogue circuitry has been programmed directly into the code. For instance, the ﬁlter algorithm is entirely built around a very precise mathematical model of an analogue ﬁlter - as are the basic components of the oscillators and envelope generators. This technique is known as Analogue Modeling. Only the LFOs, mixer, ramp and control-signal "logarithmizer" are not analogue models. You will soon see why: unlike its analogue ancestors, ACE is not susceptible to instabilities, and all oscillators can be synchronized to the song tempo. For instance, even perfectly host-synchronized beating between two oscillators. Non-linear distortion in the ﬁlters (which, by the way, are self-oscillating), the extremely fast envelopes and modulation pathways as well as certain other details (e.g. "Glide2") open up a surprising palette of sound-sculpting techniques that are not available in other software synthesizers. It is true that ACE places high demands on CPU power, and some of the typical features of recent digital synthesizers (e.g. "supersaw" or audio sample import) are nowhere to be found, but ACE rewards you with audio quality previously unheard of in the world of software synths. So can it really sound "analogue"? We'll let you be the judge of that. Layout and Signal Flow At ﬁrst glance, the architecture is similar to a simple synthesizer of the late '70s and early '80s - which was also adopted by the ﬁrst generation of "virtual analogue" hardware synthesizers of the '90s. Whenever you open a fresh instance of ACE, a default patch is loaded, without any cables. The pre-patched signal ﬂow is as follows: LFO 1 LFO 2 VCO 1 MIX VCO 2 VCF 1 VCA 1 VCA 2 E ects VCF 2 ADSR 1 ADSR 2 ACE Osc 1 Vibrato LFO 1 -> Oscillators standard signal flow diagram (internal wiring) (c) 2009 Urs Heckmann PWM LFO 2 - Oscillators LFO 2 -> VCF Cut ADSR 2 ADSR 2 ADSR 2 white noise Lowpass 1 Lowpass 2 ADSR 1 -> VCA SubOsc Osc 2 Oscillator 1, the sub-oscillator, oscillator 2 and the noise generator are merged in the mixer, and from there the signal is sent to ﬁlter 1. This ﬁlter is routed to output ampliﬁer 1. At the same time i.e. in parallel, oscillator 2 is sent through ﬁlter 2 to the other ampliﬁer. LFO 1 is used for pitch modulation by default i.e. vibrato for both oscillators, and the amount is controlled by the modulation wheel (MIDI CC#1). LFO 2 is routed to the pulse width modulation inputs of the main oscillators, as well as to both ﬁlter cuto frequencies. ADSR 1 is used as envelope generator for both VCAs. ADSR 2 is set as modulation source for oscillator pitches, both ﬁlter cuto frequencies and the amplitude of LFO 2. Always remember that these are only the default connections - they can be replaced with any signal you like by simply connecting cables. Also note that you can have several cables connected to a single output, but only a single cable connected to an input (existing connections to inputs are replaced). If you really feel the need to compare ACE with a classic modular synth (or three), think of it as a pimped-up ARP 2600 using modules from a Roland SH-7 with (almost) the patching ﬂexibility of an EMS VCS3 / Synthi A - but polyphonic. Just like the ARP 2600, ACE is pre-patched so that it will work "out of the box", but all default connections can be overridden using patch cords. Roland's SH-7 includes - like ACE - a second ﬁlter and an extra envelope generator. However, many of the modules in ACE have been designed to take on a number of very dierent or unusual tasks. For instance, you can use the ramp generator as an LFO, a multiple as ring modulator, or LFO 1 as a waveshaper. Operation Settings Note: ACE does not include global settings i.e. all values are saved and recalled with each patch. mode determines the polyphony and basic interpretation of MIDI notes: • poly - polyphonic (several notes can be played at the same time) • retrigger - monophonic, notes are always triggered, even when they overlap • legato - monophonic, notes are only triggered after ﬁrst releasing all current notes • duophonic - VCO 1, LFO 1 and VCF 1 respond to the lowest note while VCO 2, LFO 2 and VCF 2 respond to the highest note. voices (mainly for use in poly mode) sets the maximum number of notes that can be played before voice-stealing occurs. The few and medium settings can reduce CPU load, especially sounds with relatively long envelope release times. Note that stacking (see below) uses multiple voices and therefore reduces polyphony. The quality switch is also used for reducing CPU load. Depending on modulation speeds or the amount of ﬁlter distortion, quality can be reduced to standard or even draft without any audible compromises. Of course this can be decided according to how the patch is going to be used - it will sometimes be ﬁne at the bass end, but less than optimal further up the keyboard. pb up and pb down determine how many semitones the pitchbend wheel will bend notes. drift determines whether individual voices are slightly detuned against each other for a fuller, more lively sound. transpose adjusts the overall pitch, with a range of +/- 2 octaves. tune adjusts the overall pitch, with a range of +/- 50 cents i.e. half a semitone. output adjusts the overall volume. Stack The stack parameter determines the number of voices per note. Up to 8 voices can be stacked for a very powerful unison eect, just like a few classic polyphonic synthesizers e.g Oberheim OBXa. Depending on the mode and stack uploads/Litterature/ ace-guide.pdf