VCS3

_____ __ __ ____ __ ______ ____ _____

| ____| \/ / ___| \ \ / / ___/ ___|___ /

| _| | |\/| \___ \ \ \ / / | \___ \ |_ \

| |___| | | |___) | \ V /| |___ ___) |__) |

|_____|_| |_|____/ \_/ \____|____/____/

 

SIGNAL & CONTROL

(pastebin.com/ZPbqDukT)

 

 

 

o==========o

| Contents |

o==========o

 

A. General: signals and controls

 

B. Pin matrix

 

C. Envelope shaper

1. In- and output

2. Envelope generation

3. Level knobs

 

D. Models

 

E. Keyboard

1. Original keyb.

2. Keyb. & sequencer from the AKS

 

F. Examples

1. Bell with the ring modulator

2. Hi-hat with the sequencer

 

G. Glossary

 

X. References

 

-<>-<>-<>-<>-<>-

 

 

 

 

o==================================o

| A. General: signals and controls |

o==================================o

 

The VCS3 works with SIGNALS (audio signals) and CONTROLS (control voltages). Not to be mistaken with Sources and Treatments (see section about the pin matrix).

 

Both can be an in- or output. Some are on the back, some must be connected to each other via the pin matrix. The Signal and Control outputs are called "Sources" or "Treatments" depending on their function (see chapter about the pin matrix). In practice that distinction does not make a lot of sense but the distinction between (audio) Signal and Control (voltage) does!

 

Examples:

 

- You can use the output of Osc 3 (= a 'Source' on row 6) as a Control voltage to modulate Osc. 1's frequency (= a 'Control' input on column I), which works as an LFO then.

 

- Alternatively, you can use the output of Osc. 3 (Source row 6) as an audio Signal to be routed to the envelope generator (Signal Input column D) or route it directly as an (audio) Signal to output channel 1 (Signal Input column A).

 

So Osc 3 can function as a Control (voltage) or as a (audio) Signal. Maybe the first 8 pins of row 6 (the audio signals) are amplified and the last 8 (the control voltages) are not.

 

The output channels 1 and 2 must not be mistaken for the external left- and right signal (= audio) outputs on the back. They are more like two tracks on a tape machine. The output channels can both be panned to left and/or right.

 

 

 

o===============o

| B. Pin matrix |

o===============o

 

"Sources" are (audio) Signals and Control (voltages). "Treatments" modify the Signals and Controls. It's all very vague so forget about it. Just keep to Signals and Controls. For instance: the filter can self-oscillate and thus is marked as a source as well as a treatment.

 

On the orig. VCS3 and Synthi's there were 16 columns from A to P and 16 rows from 1 to 16. The pins would have different electric resistances depending on colour. So you could attenuate voltages (i.e. control voltages and audio signals).

 

Columns are IN-puts for (audio) Signals and for Control (voltages).

 

Rows are OUT-puts from Sources (which can be a signal or a control) and Treatments (to modify signals and controls).

 

One connects an output to an input, just like on a modular synthesizer.

 

_ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _ _______ Output from:

|_|_|_|_|o|_|_|_|_|_|_|_|_|_|_|_| 1 Osc 1 sine |

|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_| 2 Osc 1 saw |

|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_| 3 Osc 2 pulse |

|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_| 4 Osc 2 triangle |

|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_| 5 Osc 3 pulse |----> Sources

|_|_|_|o|_|_|_|_|_|_|_|_|_|_|_|_| 6 Osc 3 triangle |

|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_| 7 Noise |

|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_| 8 Input Ch. 1/Keyb. |

|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_| 9 Input Ch. 2/Seq.__|_

|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_| 10 Filter | |

|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_| 11 Trapezoid ________| |

|_|_|_|_|_|o|_|_|_|_|_|_|_|_|_|_| 12 Envelope signal |

|o|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_| 13 Ring modulator |--> Treatments

|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_| 14 Reverb |

|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_| 15 Stick L/R |

|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_|_| 16 Stick U/D __________|

A B C D E F G H I J K L M N O P

________________________

O M O E R R F O D R F O |

u e u n i e i s e v l u |

t t t v n v l c c r t t |

e e g e t a b r |<-- Input to:

C r C l r e F y L |

h h o A B b r r M F v |

p i r l |

1 2 e 1 2 3 x 1 2 ________________________|

| || |

|______________||______________|

^ ^

| |

Signal Control

inputs inputs

 

FIGURE 1. The pin matrix.

 

Notice that, for instance, the filter has two inputs. One marked as "Filter" for a (audio) Signal (e.g. from row 12: the Envelope Signal) and one marked as "Filter freq." for a Control (voltage) (e.g. from the Trapezoid on row 11). Just like the output from an oscillator can be two things (e.g. LFO Control voltage or audio Signal note). An Input can mean two things as well. This can be confusing to the uninitiated to modular synthesis and/or the "VCS way".

 

 

 

o====================o

| C. Envelope shaper |

o====================o

 

This is one of the most confusing aspects of the VCS3. In this document the envelope shaper will also be referred to as an envelope generator (EG).

 

One function of the envelope shaper is to generate a Control voltage called the *Trapezoid* on row 11 of the pin matrix. Just like an EG for the filter of most conventional synths. The Trapezoid Control voltage can be routed to Control Inputs. Notice that the Trapezoid takes no input (!).

 

The second function of the envelope shaper is to accept an (audio) Signal via *Envelope* on the pin matrix (column D). This generates an envelope for it called the *Envelope Signal* "Treatment" on row 12. Just like the EG for the VCA on a conventional synth.

 

Both have the same settings (e.g. on, off, attack & decay). You can set different intensities for Trapezoid and Envelope signal.

 

Schematically it looks like Fig. 2.

 

 

Input: Envelope shaper pin matrix: Output:

_________________________

| |

| Trapezoid | ----> Control

| (out) | voltage

|_________________________|

| |

audio -----> | Envelope ----> Envelope | ----> audio

Signal | (in) Signal | Signal

| (out) |

|_________________________|

 

FIGURE 2. The envelope shaper.

 

 

1. In- and output

~~~~~~~~~~~~~~~~~

Notice that the EG has only one input (for audio) and *two* outputs. The outputs are a trapezoid Control voltage to modify a Control Input and a envelope generated audio Signal. Both are set with the same knobs. Notice that the a Minimoog, for example, has two EG's for that.

 

Input, column D on matrix:

Gets input from an audio Signal and then it outputs Envelope generated audio. It's called "Envelope" on column D on the pin matrix.

 

Output, rows 11 and 12 on matrix:

- Generates a trapezoid Control voltage (= row 11), takes no input.

- Passes through the envelope generated audio Signal via row 12.

 

2. Envelope generation

~~~~~~~~~~~~~~~~~~~~~~

On most synths sustain means sustain *level*. The VCS3 has sustain *time*, called "on" time. The VCS3 does not have ADSR controls like on most synths, it's more like this:

 

____________________________________________________________

Most synths: VCS3:

____________________________________________________________

Attack Attack

Decay none (!)

Sustain level none

Sustain time On

Release Decay

none Off

____________________________________________________________

 

Sustain, or "on", time starts after attack is finished. The VCS's decay time (more like release, actually) starts after key depress.

 

The envelope generator starts again after a certain amount of "off" time. If the off time is infinite then you have to start the EG manually with the Attack button or a key on the keyboard.

 

3. Level knobs

~~~~~~~~~~~~~~

The envelope shaper has two knobs to set the intensity/level. One for the trapezoid Control voltage and one for the envelope generated audio Signal (volume). Both envelopes have the same attack, decay, on and off times off course.

 

 

 

o===========o

| D. Models |

o===========o

 

The naming for the different models of the VCS3 and its keyboards can be confusing. See table 1.

 

TABLE 1. VCS3 and keyboard models.

_____________________________________________________________________

Model (Nick) Name Remark

_____________________________________________________________________

VCS3 Putney Wooden L-shaped housing. Sometimes called

the "Synthi VCS3".

 

Synthi A Portabella In black spartanite attaché case.

 

Synthi AKS - Same as the Synthi A, but with a keyboard

and sequencer in the lid.

 

DK0, 1 & 2 Cricklewood Wooden keyboard. Has a sawtooth oscillator

and VCA on the left-hand side [2].

 

Synthi ? See the Synthi A user manual [3]. Has

keyboard only one switch...

_____________________________________________________________________

 

 

 

o==============o

| E. Keyboards |

o==============o

 

1. Original keyb.

~~~~~~~~~~~~~~~~~

The Cricklewood can maybe be used stand-alone if it outputs an audio Signal. The oscillators produces a sawtooth wave.

 

The DK1 is connected to the VCS3 using a dedicated eight-way cable that provides two power rails, two CVs, and a Gate pulse for the envelope shaper.

 

To the left of the keyboard, two switches control the two output CVs produced by the DK1. They are called 'Input Channels', probably because they show up as such on the pin matrix of the VCS3.

 

The first of these has 'Signal' and 'Keyboard Voltage' (CV1) positions. Keyboard voltage was what we would now call the pitch CV.

 

Switch 2 had a 'Dynamic Voltage' position and a 'Keyboard Voltage' (CV2) position. The former of these produces a CV proportional to the velocity with which you hit a key, while the latter produces a pitch CV. But CV1, and therefore channel one, produce the same thing, so there's no point in having both switches set to keyboard voltage. [4]

 

When set to 'Signal' input channel 1 probably is the (sawtooth) oscillator. "With the spread set to '10' the oscillator tracks the keyboard in a conventional 1:1 relationship. In other words, you can play the keyboard and you'll hear the notes that you would expect" [6].

 

2. Keyb. & sequencer from the AKS

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

This is actually two devices for one price. One is the sequencer and the other the keyboard. Both can play at the same time (see video [1])! Hence the two sources for it on the VCS3.

 

 

 

o=============o

| F. Examples |

o=============o

 

1. Bell with the ring modulator

~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~

- Osc 1 sine wave on frequency C6 into Ring modulator input A.

- Osc 2 triangle wave on freq. G5 into the Envelope generator. EG: no attack,

decay on 0.624.

- Envelope signal into Ring mod input B.

- Ring mod to output channel 1.

 

2. Hi-hat with the sequencer

~~~~~~~~~~~~~~~~~~~~~~~~~~~~

WiP ...

 

 

 

o=============o

| G. Glossary |

o=============o

 

Control = Control voltage.

Envelope = Usually the shape of the ADSR graph. Here it means the input

port of the envelope shaper which outputs an audio/envelope

signal.

Envelope shaper = We'd call that an envelope generator nowadays.

Envelope signal = The audio Signal that has been generated by the envelope shaper.

Signal = Audio signal.

Source = Mostly an audio Signal but can also be a Control voltage (Osc. 3

doubles as an LFO and an oscillator this way).

Treatment = Something to modify a Signal or Control.

Trapezoid = The Control voltage from the envelope shaper.

 

 

 

o===============o

| X. References |

o===============o

 

[1] Claude Menu's Synthi AKS video's with separate use of keyboard and sequencer:

https://youtu.be/hAxhwZMZS0s?t=243

 

[2] DK0 keyboard on matrixsynth.com

www.matrixsynth.com/2011/05/ems-dk0-keyboard-rarest-of-ems.html

 

[3] Synthi A user manual:

http://dl.lojinx.com/analoghell/EMSSynthi-UsersManual.pdf

 

[4] Two part article on Soundonsound:

https://www.soundonsound.com/music-business/all-about-ems-part-1

 

[5] Youtube EMS VCS3 with Cricklewood DK 1 keyboard:

youtube.com/watch?v=TFo0121kjIo&ab_channel=DanGolden

 

[6] The story of EMS, good info on the DK1 keyboard:

https://forum.vintagesynth.com/viewtopic.php?t=39661

 

[7] Another website on the DK1 keyboard:

www.rlmusic.co.uk/rlm3/ems-dk1/