Sequential Circuits 700 Operation Manual

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MODEL 700

PROGRAMMER

OPERATIONS

MANUAL

Model 700 Programmer – Operations Manual

PROGRAMMER OPERATIONS MANUAL

1.0 Operation

The Model 700 Programmer consists of two envelope generators and three general-purpose voltage sources, all of which are connected to the synthesizer that is going to be controlled. Envelope 1 should be connected to the VCA, and Envelope 2 should be connected to the filter control input. The voltage sources are usually patched to three VCOs. The 700 also requires a gate signal. A switch trigger (Moog), or a gate and a trigger can also be connected when available.

More detail for connection to individual synthesizers is contained at the end of this manual.

1.1Memory Selection

There are eight PROGRAM SELECT pushbutton switches that select one of eight different programs. When selected, the corresponding LED indicator on the switch will light. The MEMORY BANK rotary switch can select one of eight different memory banks. Each memory bank contains a different set of eight programs; hence 64 (8 x 8) different programs can be selected at any time. The current bank and program numbers are displayed on LED numerical displays for quick reference.

The current program can also be changed by an external signal input to the PROGRAM INCREMENT socket. The footpedal provided can be connected to this input, so that each time the footpedal is hit, the program will increment. Any other general-purpose pulse of sufficient duration (greater than 10 milliseconds) will also increment the program when connected to the PROGRAM INCREMENT. This input is de-bounced so that relatively noisy signals can still be used. The maximum frequency that can be used is approximately 20 Hz. The EDGE switch selects whether to increment the program on the rising edge of the signal ( ) or on the trailing edge of the signal ( ). The SEQUENCE LENGTH rotary switch is used to select how many programs to cycle through before resetting to program 1. That is, if the SEQUENCE LENGTH is set to 3, the program will cycle 1-2-3-1-2-3-1 etc. with each new pulse. When in the OFF position, the incoming pulses will be ignored, and no incrementing will take place. The pushbuttons are still active at all times, regardless of external pulses or the setting of the SEQUENCE LENGTH switch.

Model 700 Programmer – Operations Manual

There are many different signals that can be used to increment the program to generate interesting effects. A keyboard gate can be used, which would change the program on each new key hit. Sequencers (such as the Sequential Circuits

Co. Model 800) can be used to advance the program at the end of a sequence (the Model 800 requires the use of a special cable, # 830, to connect to the programmer). The gate output of a sequencer could also be used to cause more changes. An LFO could be connected to the PROGRAM INCREMENT, which would cause the programmer to act as a 3 x 8 sequence with envelopes (try it some time).

1.2Mode Selection

The current mode of the programmer is selected by the RECORD / VARIABLE /

PLAYBACK switch. When in VARIABLE, the front panel controls on the programmer are active. When in PLAYBACK, the front panel controls are ignored, and the programmer is controlled from memory. RECORD is a momentary position used to store the current panel settings into the currently selected MEMORY BANK and PROGRAM SELECT memory position. The RECORD position was designed to be hard to push to avoid accidental erasing of programs. Remember that whenever the RECORD switch is pushed, the current program will be erased and re-programmed with the current front panel settings. Be careful not to destroy the wrong program.

The memory in the programmer is non-volatile, meaning that it retains its information even when power is removed. This means that once a program is stored, it will always be there, no matter what happens to the programmer. There are three penlight batteries that keep the memory active when AC power is removed. The life of these batteries is equal to the shelf life, meaning that they should last a year or two. We recommend that you replace them yearly, rather than waiting for the memory to start failing. To replace the batteries, remove the four screws holding the back plate on the programmer. The three batteries are in plain view in a battery holder. Replace the three batteries with alkaline batteries for better performance, and tape them down in the same manner to avoid loose batteries. They can be replaced with the AC power connected and turned on to avoid losing the current content of the memory. If you do this, be extremely careful of the AC power present above the battery holder by the transformer, power switch, and fuse holder.

1.3Envelopes

The two envelope generators in the Model 700 Programmer have more functions than most synthesizers offer, which expands the capability of your synthesizer.

Each envelope consists of five controls: DELAY, ATTACK, DECAY, SUSTAIN,

AND RELEASE. The envelopes are initiated by the particular gate, gate-trigger, or switch trigger system being used. The following page shows graphically the

Model 700 Programmer – Operations Manual

operation of the envelopes based on the different input controls possible. The overall operation of the envelopes is very close to that on your synthesizer.

Both envelopes also have an AMOUNT control that defines the gain of the envelope. The envelopes have a 13-volt peak when the AMOUNT is all the way clockwise, and is reduced from there. On envelope 1, this will operate as a overall volume control. On envelope 2 (filter control) this will have the effect of an "amount of envelope” control. Envelope 2 also has an OFFSET control, which is simply a DC voltage that is added to the envelope. The OFFSET is not controlled by the AMOUNT control. It has the function of acting as an “initial cutoff frequency” control. Both AMOUNT controls and the OFFSET control are remembered as part of the program.

1.4Voltage Sources

The three voltage sources are usually used for oscillator control, though they could be patched to any control voltage input on your synthesizer. They have a five-volt range, which corresponds to a five-octave range on your oscillators. The VOLTAGE controls step in semitone steps when turned (quantized), which makes tuning extremely fast and easy. The voltage steps in the programmer are very accurate, but often times the oscillators in your synthesizer may not be. Remember that if your synthesizer is out of tune normally, it will be out of tune with the programmer. Some synthesizers may require that the programmer be tuned to match the synthesizer. This is fairly easy to accomplish. Remove the back panel. There is a trimmer control (black) in the lower right hand corner of the circuit board. This controls the overall gain of the output voltage from the programmer. It can be raised or lower as required for your oscillators to track. The tuning method is as follows:

1)Patch VOLTAGE 1 to one oscillator, and VOLTAGE 2 to a second. (Be sure that you tune your synthesizer according to the manufacturers instruction before performing these adjustments.)

2)Turn both VOLTAGE 1 and 2 fully counter clockwise.

3)On your synthesizer, tune the two oscillators exactly to each other.

4)Tune one oscillator two octaves above the other using the VOLTAGE control on the programmer.

5)Turn the trimmer control on the circuit board of the programmer until both oscillators are in tune, the programmer should now be in tune with your synthesizer.

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