Bristol Prophet-10

The prophet 10 was the troublesome brother of the Pro-5. It is almost two

Prophet-5 in one box, two keyboards and a layering capability. Early models
were not big sellers, they were temperamental and liable to be temperature
sensative due to the amount of electronics hidden away inside. The original
layering and 'unison' allowed the original to function as two independent
synths, a pair of layered synths (both keyboards then played the same sound),
as a monophonic synth in 'unison' mode on one keybaord with a second polyphonic
unit on the other, or even all 10 voices on a single keyed note for a humungous
20 oscillator monophonic monster.

Phil Collins used this synth, and plenty of others who might not admit to it.

The emulator uses the same memories as the Prophet-5, shares the same algorithm,but starts two synths. Each of the two synths can be seen by selecting the U/D
(Up/Down) button in the programmer section. Each of the two synthesisers loads
one of the Pro-5 memories.

There was an added parameter - the Pan or balance of the selected layer, used
to build stereo synths. The lower control panel was extended to select the
playing modes:

    Dual: Two independent keyboards
    Poly: Play note from each layer alternatively
    Layer: Play each layer simultaneously.

In Poly and Layer mode, each keyboard plays the same sounds.

    Mods: Select which of the Mod and Freq wheels control which layers.

The following text is that from the Prophet-5:

Sequential circuits released amongst the first truly polyphonic synthesisers
where a group of voice circuits (5 in this case) were linked to an onboard
computer that gave the same parameters to each voice and drove the notes to
each voice from the keyboard. The device had some limited memories to allow
for real live stage work. The synth was amazingly flexible regaring the
oscillator options and modulation routing, producing some of the fattest
sounds around. They also had some of the fattest pricing as well, putting it
out of reach of all but the select few, something that maintained its mythical
status. David Sylvian of Duran Duran used the synth to wide acclaim in the
early 80's as did many of the new wave of bands.

The -52 is the same as the -5 with the addition of a chorus as it was easy, it
turns the synth stereo for more width to the sound, and others have done it on
the Win platform.

The design of the Prophet synthesisers follows that of the Mini Moog. It has
three oscillators one of them as a dedicated LFO. The second audio oscillator
can also function as a second LFO, and can cross modulate oscillator A for FM
type effects. The audible oscillators have fixed waveforms with pulse width
modulation of the square wave. These are then mixed and sent to the filter with
two envelopes, for the filter and amplifier.

Modulation bussing is quite rich. There is the wheel modulation which is global,
taking the LFO and Noise as a mixed source, and send it under wheel control to
any of the oscillator frequency and pulse width, plus the filter cutoff. Poly
mods take two sources, the filter envelope and Osc-B output (which are fully
polyphonic, or rather, independent per voice), and can route them through to
Osc-A frequency and Pulse Width, or through to the filter. To get the filter
envelope to actually affect the filter it needs to go through the PolyMod
section. Directing the filter envlope to the PW of Osc-A can make wide, breathy
scaning effects, and when applied to the frequency can give portamento effects.

LFO:

    Frequency: 0.1 to 50 Hz
    Shape: Ramp/Triangle/Square. All can be selected, none selected should
    give a sine wave (*)

    (*) Not yet implemented.

Wheel Mod:

    Mix: LFO/Noise
    Dest: Osc-A Freq/Osc-B Freq/Osc-A PW/Osc-B PW/Filter Cutoff

Poly Mod: These are affected by key velocity.

    Filter Env: Amount of filter envelope applied
    Osc-B: Amount of Osc-B applied:
    Dest: Osc-A Freq/Osc-A PW/Filter Cutoff

Osc-A:

    Freq: 32' to 1' in octave steps
    Shape: Ramp or Square
    Pulse Width: only when Square is active.
    Sync: synchronise to Osc-B

Osc-B:

    Freq: 32' to 1' in octave steps
    Fine: +/- 7 semitones
    Shape: Ramp/Triangle/Square
    Pulse Width: only when Square is active.
    LFO: Lowers requency by 'several' octaves.
    KBD: enable/disable keyboard tracking.

Mixer:

    Gain for Osc-A, Osc-B, Noise

Filter:

    Cutoff: cuttof frequency
    Res: Resonance/Q/Emphasis
    Env: amount of PolyMod affecting to cutoff.

Envelopes: One each for PolyMod (filter) and amplifier.

    Attack
    Decay
    Sustain
    Release

Global:

    Master Volume
    A440 - stable sine wave at A440 Hz for tuning.
    Midi: channel up/down
    Release: release all notes
    Tune: autotune oscillators.
    Glide: amount of portamento

    Unison: gang all voices to a single 'fat' monophonic synthesiser.

This is one of the fatter of the Bristol synths and the design of the mods
is impressive (not my design, this is as per sequential circuits spec). Some
of the cross modulations are noisy, notably 'Osc-B->Freq Osc-A' for square
waves as dest and worse as source.

The chorus used by the Prophet-52 is a stereo 'Dimension-D' type effect. The
signal is panned from left to right at one rate, and the phasing and depth at
a separate rate to generate subtle chorus through to helicopter flanging.

Memories are loaded by selecting the 'Bank' button and typing in a two digit
bank number followed by load. Once the bank has been selected then 8 memories
from the bank can be loaded by pressing another memory select and pressing
load. The display will show free memories (FRE) or programmed (PRG).


	<< prev Sequential Circuits Prophet 10 (-pro10) (1978) next >> The prophet 10 was the troublesome brother of the Pro-5. It is almost two Prophet-5 in one box, two keyboards and a layering capability. Early models were not big sellers, they were temperamental and liable to be temperature sensative due to the amount of electronics hidden away inside. The original layering and 'unison' allowed the original to function as two independent synths, a pair of layered synths (both keyboards then played the same sound), as a monophonic synth in 'unison' mode on one keybaord with a second polyphonic unit on the other, or even all 10 voices on a single keyed note for a humungous 20 oscillator monophonic monster. Phil Collins used this synth, and plenty of others who might not admit to it. The emulator uses the same memories as the Prophet-5, shares the same algorithm,but starts two synths. Each of the two synths can be seen by selecting the U/D (Up/Down) button in the programmer section. Each of the two synthesisers loads one of the Pro-5 memories. There was an added parameter - the Pan or balance of the selected layer, used to build stereo synths. The lower control panel was extended to select the playing modes: Dual: Two independent keyboards Poly: Play note from each layer alternatively Layer: Play each layer simultaneously. In Poly and Layer mode, each keyboard plays the same sounds. Mods: Select which of the Mod and Freq wheels control which layers. The following text is that from the Prophet-5: Sequential circuits released amongst the first truly polyphonic synthesisers where a group of voice circuits (5 in this case) were linked to an onboard computer that gave the same parameters to each voice and drove the notes to each voice from the keyboard. The device had some limited memories to allow for real live stage work. The synth was amazingly flexible regaring the oscillator options and modulation routing, producing some of the fattest sounds around. They also had some of the fattest pricing as well, putting it out of reach of all but the select few, something that maintained its mythical status. David Sylvian of Duran Duran used the synth to wide acclaim in the early 80's as did many of the new wave of bands. The -52 is the same as the -5 with the addition of a chorus as it was easy, it turns the synth stereo for more width to the sound, and others have done it on the Win platform. The design of the Prophet synthesisers follows that of the Mini Moog. It has three oscillators one of them as a dedicated LFO. The second audio oscillator can also function as a second LFO, and can cross modulate oscillator A for FM type effects. The audible oscillators have fixed waveforms with pulse width modulation of the square wave. These are then mixed and sent to the filter with two envelopes, for the filter and amplifier. Modulation bussing is quite rich. There is the wheel modulation which is global, taking the LFO and Noise as a mixed source, and send it under wheel control to any of the oscillator frequency and pulse width, plus the filter cutoff. Poly mods take two sources, the filter envelope and Osc-B output (which are fully polyphonic, or rather, independent per voice), and can route them through to Osc-A frequency and Pulse Width, or through to the filter. To get the filter envelope to actually affect the filter it needs to go through the PolyMod section. Directing the filter envlope to the PW of Osc-A can make wide, breathy scaning effects, and when applied to the frequency can give portamento effects. LFO: Frequency: 0.1 to 50 Hz Shape: Ramp/Triangle/Square. All can be selected, none selected should give a sine wave () () Not yet implemented. Wheel Mod: Mix: LFO/Noise Dest: Osc-A Freq/Osc-B Freq/Osc-A PW/Osc-B PW/Filter Cutoff Poly Mod: These are affected by key velocity. Filter Env: Amount of filter envelope applied Osc-B: Amount of Osc-B applied: Dest: Osc-A Freq/Osc-A PW/Filter Cutoff Osc-A: Freq: 32' to 1' in octave steps Shape: Ramp or Square Pulse Width: only when Square is active. Sync: synchronise to Osc-B Osc-B: Freq: 32' to 1' in octave steps Fine: +/- 7 semitones Shape: Ramp/Triangle/Square Pulse Width: only when Square is active. LFO: Lowers requency by 'several' octaves. KBD: enable/disable keyboard tracking. Mixer: Gain for Osc-A, Osc-B, Noise Filter: Cutoff: cuttof frequency Res: Resonance/Q/Emphasis Env: amount of PolyMod affecting to cutoff. Envelopes: One each for PolyMod (filter) and amplifier. Attack Decay Sustain Release Global: Master Volume A440 - stable sine wave at A440 Hz for tuning. Midi: channel up/down Release: release all notes Tune: autotune oscillators. Glide: amount of portamento Unison: gang all voices to a single 'fat' monophonic synthesiser. This is one of the fatter of the Bristol synths and the design of the mods is impressive (not my design, this is as per sequential circuits spec). Some of the cross modulations are noisy, notably 'Osc-B->Freq Osc-A' for square waves as dest and worse as source. The chorus used by the Prophet-52 is a stereo 'Dimension-D' type effect. The signal is panned from left to right at one rate, and the phasing and depth at a separate rate to generate subtle chorus through to helicopter flanging. Memories are loaded by selecting the 'Bank' button and typing in a two digit bank number followed by load. Once the bank has been selected then 8 memories from the bank can be loaded by pressing another memory select and pressing load. The display will show free memories (FRE) or programmed (PRG).
Bristol is in no way associated with the original manufacturer, neither do they endorse this product. Bristol is free software. Bristol carries no logo.