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Originally uploaded on 20/01/2016. Last updated on 21/07/2023
This page was created to show the specifications of the Casio HT-700.
I have put in as much information about the keyboard as I know and this post will be updated every so often.
I have put in as much information about the keyboard as I know and this post will be updated every so often.
Specifications
Year released: 1987
Type of keyboard: Synthesizer
Analogue/Digital: Digital Analogue hybrid
Sound generation: Spectrum Dynamic Synthesis, Pulse Code Modulation (Drums)
Number of keys: 49
Key size: Mini
Touch Sensitive: No
Battery backup: No, The keyboard must be connected to a power source in order to save patches
Storage: 20 internal voices (40 with ram card), 10 custom auto accompaniment styles (20 with ram card)
Expandable Storage: Yes, Supports Casio RAM cards (RA-100)
Polyphonic: Yes, 8 notes max
Mono mode: No
Volume control: 3 Analogue volume faders (Main volume, accompaniment volume and rhythm volume)
DAC bit depth: 7bit
Type of keyboard: Synthesizer
Analogue/Digital: Digital Analogue hybrid
Sound generation: Spectrum Dynamic Synthesis, Pulse Code Modulation (Drums)
Number of keys: 49
Key size: Mini
Touch Sensitive: No
Battery backup: No, The keyboard must be connected to a power source in order to save patches
Storage: 20 internal voices (40 with ram card), 10 custom auto accompaniment styles (20 with ram card)
Expandable Storage: Yes, Supports Casio RAM cards (RA-100)
Polyphonic: Yes, 8 notes max
Mono mode: No
Volume control: 3 Analogue volume faders (Main volume, accompaniment volume and rhythm volume)
DAC bit depth: 7bit
MIDI Specifications
MIDI Ports: In, Out
Velocity: Auto accompaniment section transmits velocity data but is not capable of receiving it
Sysex support: No
Multi-timbral: Yes, 4 parts (Main voice, Chord voice, Bass, Drums)
Drums controllable via MIDI: No, but internal drum machine can be synced via the MIDI clock
Volume controllable via MIDI: No
MIDI Channels: Send and receive channel can be set to 1-13 (Chord = send and receive +1, Bass = send and receive +2, Rhythm = send and receive +3)
MIDI Clock: Can be set to internal or external
Parameters editable via MIDI: N/A
MIDI thru via MIDI out: No
Playable note range via MIDI: C1-C6 (G1-C6 for Bass)
MIDI Patch range: Main voice 0-40 (0-60 with ram card) Chord voice 0-20, Rhythm section 0-30 (0-40 with ram card)
Velocity: Auto accompaniment section transmits velocity data but is not capable of receiving it
Sysex support: No
Multi-timbral: Yes, 4 parts (Main voice, Chord voice, Bass, Drums)
Drums controllable via MIDI: No, but internal drum machine can be synced via the MIDI clock
Volume controllable via MIDI: No
MIDI Channels: Send and receive channel can be set to 1-13 (Chord = send and receive +1, Bass = send and receive +2, Rhythm = send and receive +3)
MIDI Clock: Can be set to internal or external
Parameters editable via MIDI: N/A
MIDI thru via MIDI out: No
Playable note range via MIDI: C1-C6 (G1-C6 for Bass)
MIDI Patch range: Main voice 0-40 (0-60 with ram card) Chord voice 0-20, Rhythm section 0-30 (0-40 with ram card)
Sound Generation
The Casio HT-700 generates its sounds using a synthesis method known as "Spectrum Dynamic Synthesis". It functions similar to the traditional subtractive synthesis used by synthesisers such as the Mini Moog, however, some of the waveforms 'evolve' over time. The speed of which the waveforms 'evolve' can be controlled via the DCO Envelope, however, some waveforms have a fixed envelope which cannot be altered.
While I'm not 100% sure, it may function similar to wavetable synthesis for its waveforms, as you can make waveforms evolve by simply changing the position in the wavetable.
The Casio HT-700 contains 2 voltage controlled filters with resonance, 4 envelopes (2 for the Digitally Controlled Oscillator and 2 for the filter), 2 LFOs fixed to pitch and a Stereo Chorus.
This can be divided into 2 parts; one for the main voice and one for the chord voice.
See image below on how the sound is routed.
While I'm not 100% sure, it may function similar to wavetable synthesis for its waveforms, as you can make waveforms evolve by simply changing the position in the wavetable.
The Casio HT-700 contains 2 voltage controlled filters with resonance, 4 envelopes (2 for the Digitally Controlled Oscillator and 2 for the filter), 2 LFOs fixed to pitch and a Stereo Chorus.
This can be divided into 2 parts; one for the main voice and one for the chord voice.
See image below on how the sound is routed.
As the HT-700 only has 1 voltage controlled filter per part, playing multiple notes will cause the filter's envelope to re-trigger. This also applies to the chord section.
Because the HT-700 uses both digital and analogue components in the sound generation, it is known as a digital/analogue hybrid synth.
{Updated 20/01/2016}
After listening to the Casio HT-700's waveforms, I noticed that they were generated using two parts layered on top of each other.
This technically means that the HT-700 uses two oscillators per sound channel, however the second oscillator's parameters are dependent on the selected waveform and cannot be altered by the user.
While messing around with the ES1 synthesizer in Logic, I discovered that I could replicate waveform 19 by combining a pulse wave and a square wave together (see image below).
Because the HT-700 uses both digital and analogue components in the sound generation, it is known as a digital/analogue hybrid synth.
{Updated 20/01/2016}
After listening to the Casio HT-700's waveforms, I noticed that they were generated using two parts layered on top of each other.
This technically means that the HT-700 uses two oscillators per sound channel, however the second oscillator's parameters are dependent on the selected waveform and cannot be altered by the user.
While messing around with the ES1 synthesizer in Logic, I discovered that I could replicate waveform 19 by combining a pulse wave and a square wave together (see image below).
Here you can see the result of combining the Square and Pulse waves together. The Square wave is at a higher octave than the Pulse wave. The volume of the Square wave is also lower than the Pulse wave.
In addition to layering waveforms together, an envelope can also be applied to the second part to make it fade in or out and to change the texture of the sound. This parameters of the envelope is dependent on the selected waveform but it is possible to control it on some waveforms by using the DCO envelope i.e. the time it takes for waveform 9 to evolve can be controlled via the DCO envelope.
It is also possible that the phase of the second layer can be controlled. While playing around with a sample delay which had be set to mono, I found that I was able to create a sound similar to waveform 9 by quickly adjusting the phase of two square waves produced by the keyboard. I'm not 100% sure that the keyboard uses phase modulation but it is a possibility as the CZ range of keyboards used Phase Distortion.
In addition to layering waveforms together, an envelope can also be applied to the second part to make it fade in or out and to change the texture of the sound. This parameters of the envelope is dependent on the selected waveform but it is possible to control it on some waveforms by using the DCO envelope i.e. the time it takes for waveform 9 to evolve can be controlled via the DCO envelope.
It is also possible that the phase of the second layer can be controlled. While playing around with a sample delay which had be set to mono, I found that I was able to create a sound similar to waveform 9 by quickly adjusting the phase of two square waves produced by the keyboard. I'm not 100% sure that the keyboard uses phase modulation but it is a possibility as the CZ range of keyboards used Phase Distortion.
Editable Parameters
(Parameter numbers are written in brackets. A PDF containing the full parameter list can be downloaded from here)
Main Voice
(00) Oscillator waveform (01) LFO Depth (pitch) (02) LFO Waveform (03) LFO Delay (04) LFO Speed (10) VCF Cut off (11) VCF Resonance (12) VCF Env Attack (13) VCF Env Decay (14) VCF Env Sustain (15) VCF Env Release (16) VCF Env Depth (20) DCA Env Attack (21) DCA Env Decay (22) DCA Env Sustain (23) DCA Env Release (24) DAC Env Depth |
Chord Voice
(30) Oscillator waveform (31) Vibrato (40) VCF Cut off (41) VCF Resonance (42) VCF Env Attack (43) VCF Env Decay (44) VCF Env Sustain (45) VCF Env Release (46) VCF Env Depth (50) DCA Env Attack (51) DCA Env Decay (52) DCA Env Sustain (53) DCA Env Release (54) DCA Env Depth |
Parameters which apply to the overall keyboard
(60) Chorus settings (70) Transpose (80) MIDI Send and receive channel (81) MIDI Clock |
Storage/programming
(90) Melody tone (91) Chord tone (92) Program Rhythm pattern (93) Program Bass pattern (94) Program Chord pattern (95) Save/load Chord/Operation |
Oscillator Waveforms (main voice)
The HT-700 main oscillator has 32 waveforms (or 31 as the waveform number starts at 00 on the HT-700)
I recorded each waveform without the stereo chorus and voltage controlled filter applied to it. I then imaged the waveforms using Audacity which you can see below. Some of the waveforms 'evolve' over time hence why some of the images are longer.
Click on an image to make it larger.
I recorded each waveform without the stereo chorus and voltage controlled filter applied to it. I then imaged the waveforms using Audacity which you can see below. Some of the waveforms 'evolve' over time hence why some of the images are longer.
Click on an image to make it larger.
Oscillator Waveforms (Chord voice)
In addition to the main voice waveforms, the HT-700 also has 16 waveforms which are used by the chord voice.
Click on an image to make it larger
Click on an image to make it larger
Oscillator Waveform (Bass)
The Casio HT-700 contains a non-editable bass tone with a single waveform which can be viewed below.
Drum kit
The HT-700 features a built in drum machine. It comes with 20 preset pattern as well as an additional 10 patterns which can be programmed by the user. If the user has a RAM card available then they can store 20 user patterns.
The HT-700 contains a total of 15 Pulse Code Modulated (PCM) drum samples. I don't know the exact bit depth of these samples but I suspect that it would be either 7 or 8bit.
The keyboard contains the following drum samples:
The HT-700 contains a total of 15 Pulse Code Modulated (PCM) drum samples. I don't know the exact bit depth of these samples but I suspect that it would be either 7 or 8bit.
The keyboard contains the following drum samples:
Kick drum
Snare Drum Rim shot Hi hat closed Hi hat open Ride Cymbal Clap Synth Tom high |
Synth Tom low
Timbale high Timbale low Bongo high Bongo low Agogo High Agogo Low |
Drum waveforms. Click on an image to make it larger.
MIDI modes
The Casio HT-700 has 2 Midi modes in which it can operate in. See image below
Playing Range
The HT-700 is capable of playing from C1 to C5 directly on the keyboard. An additional octave above what is accessible on the keyboard can be accessed via MIDI.
The image below shows in more detail the playing range of the HT-700.
The image below shows in more detail the playing range of the HT-700.
This applies to both the main and chord voices. The bass voice can only go down to G1 although the bass sounds are actually produced an octave below.
Voices list
Preset
01 Piano 1 02 Harpsichord 03 Jazz Organ 04 Brass Ensamble 05 Symphonic Ensamble 06 Synth Bells 07 Magical Wind 08 Blues Harmonica 09 Light Harp 10 Plunk Extended 11 Electric Piano 1 12 Vibraphone 13 Synth Clavi 14 Strings 1 15 Synth Bass 16 Synth Celesta 17 Pearl Drop 18 Synth Reed 19 Fantasy 20 Typhoon Sound |
Internal (Can be overwritten by user)
01 Piano 2 02 Marimba 03 Pipe Organ 04 Strings 2 05 Synth Ensamble 06 Synth Vibraphone 1 07 Koto 08 Double Reed 09 Clarinet 10 Miracle 11 Electric Piano 2 12 Vibraphone 2 13 Violin 14 Synth Strings 15 Synth Ensamble 2 16 Synth Vibraphone 2 17 Synth Harp 18 Slash Reed 19 Synth Guitar 20 Explosion |
Auto Accompaniment Styles
Upper Bank (User bank uses the same styles)
01 Rock 1 02 8 Beat 1 03 16 Beat 1 04 Disco 1 05 Pops 1 06 Swing 07 Slow Rock 08 Samba 09 Bossa Nova 10 Waltz |
Lower Bank
01 Rock 2 02 8 Beat 2 03 16 Beat 2 04 Disco 2 05 Pops 2 06 Electronic Pop 07 Reggae 08 Salsa 09 Beguine 10 March |
Voice examples
The Casio HT-700 features the same preset voices as the Casio MT-600, just arranged in a different order. To get an idea on what they sound like, you can watch my video titled "Casio MT-600 preset voices, chord voices and auto Accompaniment styles" below.
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