Sequential Prophet-10 Keyboard

NOTE: B-Stock keyboard from Sequential. Opened packaging. As-new condition. Full warranty.

Sequential Prophet-10 Keyboard – analog polyphonic classic with 10 voices and Rev filter selection

The Sequential Prophet-10 Keyboard is a ten-voice analog polysynth that builds on the legacy of the Prophet-5. The instrument brings together three historic revisions (Rev1, Rev2, and Rev3) by combining authentic Curtis components for the VCOs and filters (as used in Rev3) with a new 2140 low-pass filter designed by Dave Rossum, a modern counterpart to the classic 2040 filter from Rev1/Rev2. A Rev switch lets you select the filter design and also adjusts the filter envelope’s shape and response to match Rev1/2 or Rev3 respectively.

Sound engine, oscillators, and filter

Each voice features two CEM 3340 VCOs. Oscillator A offers sawtooth and pulse waveforms, while Oscillator B offers sawtooth, triangle, and pulse, with pulse width available per oscillator. Hard sync is available (oscillator 1 syncs to oscillator 2), and oscillator 2 can be switched to low frequency mode as well as keyboard tracking on/off. In the mixer section, the levels of oscillator 1, oscillator 2, and white noise can be adjusted.

Switchable low-pass filter with Rev character

The Prophet-10 features a four-pole resonant low-pass filter per voice that can be switched between Prophet-5 Rev1/2 character and Prophet-5 Rev3 character. The Rev1/2 mode uses a 2140 filter (designed by Dave Rossum), while the Rev3 mode uses a CEM 3320 filter (designed by Doug Curtis). The filter can be driven into self-oscillation with the Resonance control and offers keyboard tracking in off, half, and full modes.

Envelopes and LFO

The Filter Envelope and Amplifier Envelope are both four-stage ADSR generators, with velocity modulation of envelope amount. The LFO section offers three waveforms (sawtooth, triangle, square), with multiple waveforms available simultaneously. Modulation can be controlled via both Initial Amount and the mod wheel, with destinations including oscillator A/B frequency, oscillator A/B pulse width, and filter cutoff.

Modulation, vintage behavior, and performance control

Poly Mod is present with the same core concept as the original: sources are the filter envelope and oscillator B, and destinations include oscillator A frequency, oscillator A pulse width, and filter cutoff. The Prophet-10 also features a Vintage knob that recreates the character of various Prophet-5 models by varying the behavior of oscillators, envelopes, amplifiers, and other parameters — from a stable “4” (Prophet-5 Rev4 as an internal reference) down to “1,” emulating the Prophet-5 Rev1.

Velocity, aftertouch, and performance features

The keyboard is a five-octave, full-size, semi-weighted Fatar with velocity and channel (mono) aftertouch. Aftertouch can be routed to filter cutoff frequency and LFO amount. Performance controls include a mod wheel and a spring-loaded pitch wheel with selectable range per program (1 to 12 semitones up and down). Glide (portamento) supports polyphonic glide.

Bi-timbral: layers and splits

The Prophet-10 is bi-timbral and can play two different programs simultaneously. In Layer mode, two different 5-voice programs are stacked, while in Split mode the keyboard is divided into two independent, user-assignable zones with different 5-voice programs in each.

Unison, memory, and direct access

Unison mode is monophonic and features configurable voice count from one to all ten voices, as well as key modes. Patch memory consists of 200 user programs and 200 factory programs, organized into five banks of 40 programs each. Direct program access is supported, including Prophet-5-style single-button access to the current set of eight programs. The Preset switch functions so that when it is off, the front panel is live — what you see is what you hear.

Connectivity, CV/Gate, and power

Connectivity includes a mono output (1 x 1/4” jack), headphone output (stereo, 1 x 1/4” jack), MIDI in/out/thru, and USB for bidirectional MIDI communication. External control is supported via control voltage in/out (1 x 1/4” jack) with a 0 to +5 V signal, configured for 1 volt per octave. Gate in/out (1 x 1/4” jack) accepts a 1.5 to 15 V on/off signal to gate the envelope of a single voice and outputs a 15 V on/off signal to gate external synthesizers. Additional inputs are provided for low-pass filter cutoff expression pedal, volume expression pedal, and sustain footswitch.

Power is supplied via an IEC AC inlet with an internal power supply, and the instrument operates worldwide on 100–240 V (50–60 Hz) with a maximum power consumption of 28 W.

Construction and format

The Prophet-10 is built for touring with an all-steel construction and a body/trim made of black walnut heartwood. Dimensions are listed as 94.92 x 41.52 x 15.11 cm, and the weight is 14.51 kg.

Specifications

• Type: Analog polysynth (keyboard synthesizer)
• Polyphony: 10 voices
• Oscillators: 2 x CEM 3340 VCO per voice
• Waveforms: Osc A: sawtooth, pulse; Osc B: sawtooth, triangle, pulse
• Hard sync: Yes (osc 1 sync to osc 2)
• LFO: sawtooth, triangle, square (combinable)
• Filter: 4-pole resonant low-pass per voice, switchable Rev1/2 (2140) / Rev3 (CEM 3320)
• Keyboard tracking: off / half / full
• Envelopes: ADSR for filter and amplifier, velocity modulation of amount
• Poly Mod: Sources: filter envelope, osc B; destinations: osc A freq, osc A PW, filter cutoff
• Vintage knob: Yes (“4” stable to more “1” behavior)
• Aftertouch: Channel (mono), destinations: filter cutoff, LFO amount
• Keyboard: 5 octaves, full-size, semi-weighted Fatar, velocity + aftertouch
• Pitch/mod: Mod wheel; spring-loaded pitch wheel (1–12 semitones up/down)
• Glide: Polyphonic glide (portamento)
• Bi-timbral: Layer (2x5 voices), Split (2 zones, 5 voices each)
• Unison: Monophonic, 1–10 voices, key modes
• Program memory: 200 user + 200 factory (5 banks x 40)
• Outputs: Mono out (1 x 1/4”), headphones (stereo, 1/4”)
• MIDI: In / Out / Thru
• USB: USB MIDI (bidirectional)
• CV/Gate: CV in/out (0–+5 V, 1 V/oct), Gate in/out (1.5–15 V in, 15 V out)
• Pedal inputs: Filter cutoff expression, volume expression, sustain footswitch
• Power: IEC AC, internal PSU, 100–240 V, 50–60 Hz
• Power consumption: Max 28 W
• Dimensions (L x W x H): 94.92 x 41.52 x 15.11 cm
• Weight: 14.51 kg
• Construction: All-steel, body/trim in black walnut heartwood