Voici les informations obtenues suite à un échange de mail avec ROBIN WOOD de chez EMS
18th July 2007
Dear Tristan,
I am sending you a list of ‘standard’ modifications which we are able to carry out at our workshops here. You may find this varies from the list which you obtained from Graham Hinton’s web page.
Oscillator stabilisation (per osc) standard on new Synthis 18.00
Oscillator Sync – variable via potentiometer(per osc) 20.00
Voltage Controlled Shape (per osc) 20.00
Hi/Lo frequency range – switchable (per osc) 25.00
Portamento/glide 45.00
Attack time extension – increased to 5 seconds 15.00
Voltage Controlled Filter Response (‘Q’) 40.00
10-turn pots on input channels – for easier tuning (each) 15.00
Centre-zero trapezoid – gives inverted bipolar output 30.00
Patchable Voltage Inverter 35.00
Extra Input Channel 30.00
Switchable 18/24 db per octave filter 15.00
Filter ‘unslew’ switchable on filter’s CV input 15.00
External gate input using Control Output socket 6.00
The most popular modifications are Oscillator sync, Filter slope switch, VC Shape, Hi/Lo switchable oscillator range and the patchable inverter. All modifications are fitted at our workshop in Cornwall.
We can also supply basic spares and manuals:
Patch Pins (each) 4.00
Mains lead for VCS3 or AKS 8.00
Keyboard cable for AKS 27.00
Keyboard cable for DK2 28.00
Jack lead with 100K resistor – for MIDI to CV operation 6.00
VCS3 Mark 1 manual - by Tristram Cary 1969 8.00
Synthi Educational Handbook – for AKS & VCS3 Mk11 12.50
Synthi Book of Sounds – 28 patches for AKS/VCS3 Mk 11 6.00
Service Manual for Synthi AKS, VCS3 and DK keyboards 28.00
Blank patch sheets – specify VCS3, A, AKS, Mk1 or Mk2 (each) 0.50
Prices are in UK pounds and do not include shipping.
Note that it is not a very good idea to have all possible modifications fitted to the Synthi.
For a Synthi A there is very little in the way of free panel space for adding many more switches, and especially potentiometers. The VCS3 has more space available for additions. A balance between panel clutter and additional functionality is important to bear in mind. For example fitting oscillator sync on all thee oscillators would add three pots and three switches but you would never use all three syncs together at once and the panel would be instantly very cluttered. I usually suggest fitting sync to one oscillator – say oscillator 2.
Oscillator stabilisation is recommended on all three unless fixed pitches are not relevant to your work. Hi/lo frequency ranges are not often requested on all three oscillators but this can be done if you wish (one extra switch per oscillator).
VC shape is good for thickening sounds – principally through Pulse Width Modulating Osc 2′s square wave (also Osc 3 if Hi/Lo has been added there).
Triangle/ramp shape mod is also available simultaneously. Note that VC shape for Osc 1 will just produce a crunchy distorted sine-wave and the Osc1 ramp wave is not shape-controllable, so best omit it here. If only Oscillator 2 is modified the mod is normally made by switching the function of the reverb mix column (M) on the matrix between VC reverb mix and VC shape. Alternatively, to minimise the extra switches a 3.5mm socket can be fitted to the oscillator panel (2 and 3 if
3 is Hi/Lo) and connections direct to the matrix made by pin-to-3.5mm jack cords. This avoids the robbing of the simultaneous VC reverb mix function but increases the spaghetti factor. Much easier on a VCS3 where there is lots of free panel space for more sockets, pots and switches.
Switchable filter 18/24 db per octave is a very good deal for 15 UKP.
Switchable Filter Unslew is also recommended as it allows much faster modulation of the filter from a CV and hence an extension to the range of sounds available.
You may have noticed how there is a slight portamento when you use the filter as an oscillator. The CV breakthrough in the ‘unslewed’ position also gives a nice click for percussive ounds when using a fast CV.
The patchable inverter is a very handy tool as it simply turns a voltage upside down. For example if you have an ascending sequence of notes and feed this into the inverter you will hear a descending scale instead. Input and output are via a single pin-to-3.5mm cord providing the function at one pin location. Invert and non-invert on a pitch sequence simultaneously with two oscillators is interesting. This function also facilitates VC panning, inverted filter sweeps and many others.
Portamento needs an additional panel potentiometer and switch so for a Synthi A careful consideration is needed (especially if you definitely want Oscillator Sync on one oscillator, which will already have added one potentiometer). There is no obvous panel-space for the Portamento rate pot, unless it is jammed-in down by the joystick.
VC Filter Response is a bit of a ‘specialist’ mod. It allows the Filter Response
(resonance) to be voltage controlled. Connecting to it is probably best done via a pin-to-3.5mm cord.
On a Synthi A you can only fit a 10-turn pot to Input Ch1 due to clearance problems to the AC mains transformer for Ch2.
Extra input channels are a problem on a Synthi A as these require extra Jack sockets and there is no free panel space (again this is better on a VCS3). In any case the extra inputs are switched-in to the joystick rows so they cannot be used simultaneously with the joystick. You should consider the wisdom of doing this bearing in mind that you do have two input channels as standard and can use special pin-ended cables to inject external signals direct into the matrix if necessary.
This should help you to sort out which modifications are likely to be most useful to you. If you have any specific requirements for other modifications we will be pleased to quote for these too.
Let me know if you need any further details.
Best wishes – Robin Wood
