Module Controls & Ins/Outs
cv8w.JPG (34025 bytes)

8 CV Step Control Voltage Sequencer

Inputs:
Reset In
Clock In

Outputs:
2 x CV Range 0-5V /10V
8 x Step Outs (on=5V)

Power:
+/-12V, +5V

Controls:
8 x CV knobs

Indicators:
8x Step LED's

Size:
18HP

Introduction

The CV8 are single channel completely independent sequencers, they can be bought as and when they are needed, they can be clock at different clock divide ratios, they can each have different step lengths. None of these features are available with multi-channel sequencers.

These sequencers have a step out socket for each step (mainly for use with adjusting sequence length. Other sequencers use switches to change length). The advantage is that the sockets need not only be used for changing sequence length, but they can be used individually to clock or trigger other devices. The 8 step outs are basically the same as a Doepfer A161 trigger sequencer module making the CV8 and GT8 exceptional value.

When used with the master clock module MC01 , all sequencers can be reset globally from the Master Clock and they will be reset to THE LAST STEP. With just about all other sequencers, especially when using MIDI as the master clock, the sequencer must manually be stepped to the last step, otherwise when the clock is started, step 2 is in fact the first step triggered. Our automatically go to the last step eliminating this problem (see note in MC01 section for more explanation).


Main Applications

The CV8 comes with a 5V range as standard. This range is ideal for controllingmost control voltage inputs on analogue synth's, such filter cut-off, pulse width, etc. but more importantly 5V is a good range for controlling pitch.

If requested when ordering, the CV8 can be given a 12V range. This is needed for controlling Concussor drum voice Accent levels, and some synths that require a larger range.

It is possible to change to range between 5 and 10V by adding or removing resistor R13 (100K) on the main board. Having this resistor in place makes the range 10V. Changing this yourself is safe to do but will invalidate the warranty. A better way to have selecatble range is to remove the second CV out, and replace this with a SPDT switch to enable the resistor to be switch in and out.


Controls In Detail - standard operation.

Clock In:

The CV8 requires a +5V clock signal. Each clock signal will advance the sequencer 1 step. When the last step is reached, it resets back to the first step. Take the clock signal from an LFO, Clock module or MIDI to Clock converter.

Step Outs:

There are 8 step out sockets. As each step 1 to 8 is reached, the corresponding step out socket will go high (output +5V). By patching one of these outputs into the Reset In socket, the sequence length can be altered between 1 to 7 steps long. For example, to obtain a five step sequencer, patch the next number up step output into the reset input, i.e. step out 6. To have an eight step sequencer, no reset patch is needed.

CV Out:

This socket will output a control voltage set by the pot for the current step. It can be changed in real time. The CV is available on two parallel sockets.

Step Button:

This allows the sequencer to be manually stepped by one step at a time whilst the clock is not running. It can also be used to reset the sequence. As with most analogue sequencers, step it to the last step (8 or whatever is patched) so that when you start the clock, the sequencer starts on position 1.

Note: The step button will only work when any clock input signal is at a low state (0V). So it will note work when the clock input is high. This situation will note arise in normal use, as one would only normally use the step button when the master clock is stopped (making the clock signal low). If the sequencer is being clocked by a clock divider, even when the clock is stopped, it is possible that the clock signal may still be high until reseted.

CV pots:

There are 8 CV pots, 1 for each step. The voltage range is 0 to 5V. This can be increased to 0-10V via small internal modification.

LED Indicators:

There are 8 LED's. These will light in turn to show step position.

Alternative Applications Of Controls:

Clock In:

The sequencer does not have to be stepped through at normal regular intervals as is usual. It can be clocked from any source, such as the gate from a MIDI-CV converter or monosynth, the trigger out of a drum machine such as the TR606/808, or from the gate outputs of other analogue sequencers. This allows it to step through the sequencer rhythmically, as and when you want.

Reset In:

The reset signal does not need to be taken from the step outputs. It can be taken from an source, such as Gates from MIDI to CV converters, synth's or other analogue sequencers.

Step Outs:

These can be used individually to clock other analogue sequencers, to trigger analogue percussion modules, gate monosynths, or control analogue switching modules such as our fill-in module FS01.

Each step out is basically a divide by 8 clock divide (relative to the clock input signal). Any step output (normally step one) can be used to clock something else 8x slower.

CV Out:

If a very high frequency clock pulse is used to step the sequencer (in audio frequencies), the CV pots can be used as a waveform generator. Because of the quantised steps, it will sound digital in form, unless an external slew rate generator (portamento) module is used to smooth the waveform.


More CV8 Example Patching

Standard connection to a monosynth to control pitch and gate;
CV out to CV in on synth
Split the clock going to the sequencer (using a multiple) and send to Gate in.

Filter control of monosynth;
CV out to Filter cut-off input.

Connect CV and Gate of synth to another sequencer or MIDI to CV converter.

Alternative connections to a monosynth;
Plug CV out to CV in
Step 1 out to Gate in

The synth will be triggered on the 1st step. If the release time is long, you can still hear the pitch changing with each step, but without the EG re-triggering.

Miscellaneous Connections;

Any step out is a divide by 8 clock divider.

Take step 1 (or any other step output) into the clock of another sequencer.

Use a quantiser if you want to precisely control to pitch of a synth.

Use a voltage scaler to scale down the control voltage to a smaller range when necessary.

Take different step outputs (from same or other CV/GT8 sequencers) and mix them with a multiple to get another gate sequencer.

When using a clock other than our MC01 master clock module, (as with all analogue sequencers), you must manually step to the last step of the sequence before you start the clock. This is done automatically when using the MC01.

Using a CV8, GT8 & MC01;
Run one at 1:1 clock ratio, and the other at a divided down clock ratio, say 1:4 for interesting effects.

To control transpose:
Use 2 CV8s (we'll call them A and B) and a mixer.

Clock the CV8 A 1 step every bar. Clock CV8 B as normal. Feed the output CVs of both through a mixer (like the MX61), then take the output of the mixer to a synth as normal. CV8 A will control the transpose level, changing every bar. CV8 B sets the pattern of notes as normal. This is a handy and easy way of shifting the pitch of all 8 steps up or down with only one pot.