TheorySynth

TheorySynth is a family of modular, analogue, digital and sound chip synthesizers built by Theorysonic.

Notable users of TheorySynths include William Benter, Brock Baker, Mitsuomi Ekomoto, Rinava (Clemente Rossini), Kagami Ochiai, Jaylin Rounds and Aza Hanamaru, as well as various non-El Kadsreian artists and bands include Michael Jackson, INXS, Europe, Dream Theater, BABYMETAL, Prince and Jean-Michel-Jarre.

Keyboard synthesizers

 * TKO - Released in 1979, TKO is a modular analogue synthesizer, consisted of several modules which create and shape sounds, which are connected via patch cords. The modules in question include voltage-controlled oscillators, amplifiers, filters, envelope generators, noise generators, ring modulators, tone distortion, triggers and mixers. Its keyboard spans nine octaves, and the keyboard expression allows for velocity sensitivity and aftertouch.
 * TKONano - A portable, self-contained model of TKO, released in 1981, its keyboard has five octave, rest is accessed with a pitch bender.
 * TKOK - A keytar variant of TKONano, released in 1982.
 * AXN - A digital synthesizer, released in 1983, using FM synthesis. It has 18-note polyphony, meaning 18 notes can sound simultaneously and 36 sound-generating algorithms. Its keyboard spans nine octaves, and the keyboard expression allows for velocity sensitivity and aftertouch. It also includes pitch bender. It has cartridge support, but voice patches can be also saved to and loaded from an external cassette recorder.
 * BoxSynth - A miniature analogue electronic keyboard musical instrument played with a stylus. It doesn't have a pitch bender, unlike other TheorySynth models. Released in 1984.
 * Titanium - A series of TSUG-based synthesizers from 2005 with 2,560 programs (1920 preloaded), 1,792 combos (256 preloaded), 264 drum kits (104 preloaded), 256 GM2 programs and 9 GM2 drum kits. 100 GB internal mSATA SSD, 8 GB internal RAM (4 GB available for samples), as well as over 1000 effects. It has 104 keys and two pitch benders, and the keyboard expression allows for velocity sensitivity and aftertouch. It has cartridge support, but voice patches can be also can be also saved to and loaded from an external MMC/SD card, NanoFlash (since 2020) or USB flash drive, or even wirelessly from and to a TheoryPhone, TheoryTablet, a TheoryDesk or a TheoryBook.

Sound chips and MIDI
Trackers such as Deflemask and Furnace now emulate the sound chips.
 * TS8910 - A clone of General Instrument's AY-3-8910, released in 1983.
 * TSSN - A clone of Texas Instruments' SN76489, released in 1983.
 * TSSID - A clone of MOS 6581 SID of Commodore 64/128, released in 1984. It sounds like a combination of 8580 and 6581 variants. Unlike the original Commodore 64, TSSID officially supports the 4th channel, used as PCM, where it was often perceived as an unofficial hack in Commodore computers. Commodore 64 models sold in El Kadsre use TSSID instead of original SID due to Theorysonic owning a 7.2% stake of Commodore International's EK branch.
 * EK447 - A hybrid wavetable/FM synthesizer with 10 synth channels and 10 ADPCM channels at 47.5kHz sampling rate, using surround sound, released in 1985. The waves can be: pulse (at any duty cycle), triangle, sawtooth, noise (periodic, white, red, brown, pink, blue or black), sine, half-sine, absolute-sine, alternating-sine, "camel"-sine or pseudo-sawtooth. All "synth" channels are 12-operator, using DAHDSR (delay, attack, hold, decay, sustain, release) envelope with customisable tremolo and vibrato depth. The ADPCM can support up to 2048 samples and 16 MB of external memory for wave data. Used in several arcade machines by Drillimation Studios, Capcom and SNK. Also a popular high-end, professional version of TheorySound sound card expansion for TheoryDesks (unlike low-end versions that use non-Theorysonic sound chips such as YM2608). The EK447 version of TheorySound is also available for IBM PC compatibles and NEC PC-9801.
 * TX891 - A cut-down version of EK447 with only 5 synth channels and 5 PCM channels and stereo sound, an expansion sound chip used in Famicom and MSX ports of Mr. Driller and Xoshi. Famitracker now emulates the sound chip.
 * TSEK-0111 - a MIDI synthesizer module first released in 1987. Since it was made prior to the release of the General MIDI standard, it uses its own proprietary format for MIDI file playback. It uses "adaptive synthesis", comparable to Roland's linear arithmetic (LA) synthesizers, it comes with a preset library of 500 synth and 60 rhythm sounds, playable on 16 melodic channels and four rhythm channels. It also features a digital reverberation and reverse reverbation effect. It has surround sound. TS-UGOS had native support, but drivers for Amiga, Sharp X68000 and X1, FME-7, FM Towns, NEC PC-8801, NEC PC-9801, Atari ST, MSX, MS-DOS, CP/M, Amstrad, Sincialr ZX Spectrum, Commodore 64/128, Macintosh, UNIX and Linux were also officially supported.
 * S18X1 - A speech synthesizer chip, released in 1988. It features four configurations of a voice: English Male, English Female, Japanese Male and Japanese Female, unlike other speech synthesis chips, S18X1's sounds are far more realistic than the competition. Used in various arcade machines. In addition, it also can synthesize various animal sounds.

Sampling sequencer

 * SMPA - A sampling sequencer, released in 1985, that combines both sampling and sequencing functions, allowing users to record portions of sound, modify them and play them back as sequences. It supports a wide range of digital effects including reverb (types are Hall, Room, Vocal, Cathedral and Plate) with reverb time up to 40 seconds, delay, echo, flanging, chorusing, reverse reverb, reverse echo, ducking, ring modulation, exciter, harmonizing, equalization, pitch modification, G Major and distortion (hard clipping, fuzz or soft clipping, or a combination of those), and is capable of generating multiple effects at once. It is capable of 5.1 surround sound.

Reception
The TheorySynth synthesizers are a very popular tool in music of then-Vlokozu Union.