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Sequential Circuits | Prophet-T8


A monstrous 8 voice polysynth from SCI! The T8 has a very fat Prophet-5-like tone. This synth adds many illustrious new features (for its time) such as full MIDI implementation, 76 full size weighted keys with velocity and polyphonic aftertouch, split/layer double/unison keyboard modes, and a simple but useful real-time sequencer. The new keyboard features many dynamics enhancements, ie: aftertouch can affect pitch, level, filter or the LFO. It was Sequential's finest analog synthesizer. Digital control of analog sound with an extremely flexible, intuitive and beautiful design - right down to the wood panels!

Unfortunately the T8 suffered from the popularity of the much cheaper Yamaha DX7 back in 1983 when they were released. Although it still sounds great, the weighted keyboard is the T8's best feature making it the Rolls Royce of analog synthesizers. Generally these beasts are hard to find today and still very expensive.

The T8 has the same VCO configuration and filtering as the Prophet 5. The unique Sync function, which allows oscillator B to modulate the filter, frequency or modulation width of oscillator A. Oscillator B has a triangle waveform that was not on the Prophet 5 but both instruments have a triangle wave in Oscillator B. Additionally a knob in the LFO mod section gives control of the initial LFO modulation. New features like polyphonic glide and programmable volume , as well as digitised envelopes while still keeping the Oscillators themselves analog. The T8 has two processors with the keyboard scanning run by a Z80 CPU, while the synth itself was run by (routing, presets, envelope generation, and sequencing) the then newer Z8000 CPU.

BrandSequential Circuits
Engine TypeAnalog
Voices (max)8
LFOWaveforms: square, triangle and sawtooth. Destinations: osc a, osc b, pulse width, filter.
Engine Detailed2 VCO's per voice (16 oscillators)
Filter (VCF)24dB/oct low-pass with cutoff, resonance, env amount, key tracking
Envelope (VCA)2 ADSR envelopes per voice
Memory128 Patches
Recording670 notes
Key typeKeys
Produced:1983 - 1983
Legend: Obvious Y: Yes, N: No, N/A: Not Applicable
VCO Voltage Controlled Oscillator DCO Digital Controlled Oscillator
LFO Low Frequency Oscillator Sub Sub Oscillator
VCF Voltage Controlled Filter VCA Voltage Controlled Amplifier
Velocity As with a piano, the harder you hit a key, the louder the sound, unlike most organs which always produce the same loudness no matter how hard you hit a key. Aftertouch Pressing a key after you activated it. Channel Aftertouch, no matter which key, it will send a Channel message. Poly Aftertouch, sends the pressure per key instead of the whole channel.
Values for OSC, LFO, Filter, Envelope are per voice unless stated otherwise.

Manuals, patches etc.


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