>
> --- In SergeModular@yahoogroups.com, "riluttante" <riluttante@> wrote:
> >
> > Here's an unusual item:
> > http://cgi.ebay.com/ws/eBayISAPI.dll?ViewItem&item=120042577381
> >
> > Just my kind of thing, a Serge with a "Prestopatch" connector, like
> on the EMS Synthi A (no,
> > I'm not the seller)
> >
> > Not sure how it works though...
> >
> > Thomas
> >
>
> Hi Thomas,
>
> I've won that auction, it took some time to get here. It's my first
> Serge device. According to a few scriblings inside it was created in
> '78. That's all I know about this device.
Hi Simon,
Cool, congratulations
> I put some pictures here:
> http://www.xs4all.nl/~srroekel/SynthiSergefront.jpg
> http://www.xs4all.nl/~srroekel/SynthiSergeBack.jpg
>
> Can anyone tell me some more about the modules or something else about
> this device?
Following are some excerpts from a 1970's Serge catalog that can be found as a PDF in the
Files section of this group.
From what I can tell, the modules from left to right on your panel are:
- Some sort of sequencer?
- KEYBOARD ENVELOPE GENERATOR (KEG)
The KEYBOARD ENVELOPE GENERATOR (KEG) is specifically designed to
interface with existing keyboard type synthesizers. This module provides the
useful ADSR type of envelope with full voltage control over the Attack, Decay,
Sustain, and Release. The pre-scaled VC inputs are calibrated at 1 volt per
octave.
- SMOOTH & STEPPED GENERATOR (SSG)
The SMOOTH & STEPPED GENERATOR (SSG) is a complex multifunctional
module which can be patch-programmed to provide various slew and sample
functions. The Smooth section will place a positive and negative slew on input
voltage transitions for lag effects, voltage controlled portamento, and for low
frequency filter applications. With the Cycle jack patched to the input, the unit
will oscillate yielding a voltage controlled triangle wave LFO. A high level into
the Hold input will enable the Smooth Function to be used as a track-and-hold
circuit with voltage controlled slew rate.
The Stepped Function can be used as a sample-and-hold with voltage
controlled slew rate limiting. With the Cycle jack patched to the input and a
pulse applied to the Sample input, complex staircase waveforms are generated
for control voltage applications and for use as audio signals.
The Coupler is an internal comparator which compares the output levels
of the Smooth and the Stepped Generators. This output is useful for generating
complex control voltages and for the production of random voltages.
- DUAL UNIVERSAL SLOPE GENERATOR (DSG)
The DUAL UNIVERSAL SLOPE GENERATOR (DSG) is the ultimate patch
programmable control voltage generator in the Serge system. People familiar with
our previous series of modules know that we have produced a wide variety of
"slewing" modules, each performing specific functions for control voltage generation
and processing. These have, for the most part, been replaced by the DSG. Among
the modules which have been superseded are the VC Slew Generator, the VC
Envelope Generator, the Positive Slew and the Negative Slew. The Universal Slope
Generators are slew limited unity gain voltage followers whose positive and negative
slewing rates are voltage controllable in an exponential manner. The range is very
wide, covering sub-sonic to high audio frequency rates. Trigger inputs and pulse
outputs are included to extend the use of the slewing amps for use as low frequency
oscillators, transient (envelope) generators, and VC variable pulse delay monostable
functions. Two VC inputs are provided, one is calibrated at 1 volt per octave (±3%),
and the other is fully adjustable in the negative and positive direction. This input can
be switched to control either the positive or the negative slope or both. The linearity
and accuracy of the slewing amplifiers allows them to be used in the most exacting
applications, such as portamento functions. Among the functions which one Slope
Generator can be patch-programmed to perform are the following:
1. VC Transient Envelope Generator. The transient may be simply started with
a trigger, or with a gate input, a sustain level can be achieved.
2. VC LFO. The waveform is voltage controllable from saw to triangle.
3. VC Timing Pulse Generator.
4. VC Portamento device. The accuracy of the slew amps makes this portamento
function useful for keyboard use and for generating control voltages of arbitrary
shapes and times with Digital-to-Analog computer control. This latter use is an
extremely economical computer application, since only two voltages are needed to
generate any segmented envelope sequence.
5. Envelope Follower (Detector). The decay rate is voltage controllable with the
unique function that under voltage control the response may be moved from positive
peak to negative peak detection.
6. VC Pulse Delay (Monostable).
7. Sub-Harmonic Series Generator. A trapezoidal waveshape is generated for
sonorous, smooth sounds.
8. Audio Generator. The range reaches 4000 Hz and the waveform has variable
symmetry (saw to triangle).
9. Non-Linear Low-Pass Filter. The slew limiting is voltage controllable. A sawtooth
input will progressively transform to a triangle wave, to full attenuation. Thus a
Slope Generator can be used as a low-fidelity VCF.
- WAVEMULTIPLIER (WM)
For generating and modifying sound, the typical synthesizer patch is that
of the VCO-VCF-VCA linked in that order. The VCO provides control of
frequency, the VCF is able to dynamically vary timbre, and the VCA controls
the amplitude of the final sound. The Serge Modular WAVE MULTIPLIERS
(VCM) provide a new link in this chain, representing an advance in synthesizer
technology. In this typical patch, the Wave Multiplier could be placed just
before the VCF. Like the VCF, the Wave Multipliers affect the timbre. Unlike
the VCF's, whose action is a subtractive process of attenuating (filtering)
frequencies in an input waveform, the Wave Multipliers are able to dynamically
multiply the input waveforms to add new harmonically related frequencies.
This multiplying function is highly non-linear, and should not be confused with
ring modulation which is a linear multiplicative form of modulation. Just as it is
really impossible to describe what a VCF sounds like, it is difficult to convey the
action of the Wave Multipliers. The nearest we can come to describing the
unique qualities of this new module is to say that the Wave Multipliers function
as timbre modifiers in exciting new ways, and which offer alternative forms of
signal processing which are unique in the Serge Modular Music Systems.
There are actually three entirely separate and different types of
wave multipliers in this module. These provide an enormously varied
palette of effects, since they can be used together in a multitude of
ways.
The uppermost Wave Multiplier is the simplest of the three
multipliers. Like many of our modules, it is multi-purpose. With its switch
set at "HI", the module functions to "square" up an input signal. The
audible result of this function is similar to overdriving a tube-type amplifier,
except with full manual and voltage control of this process. With the switch
in the "LO" position, the module is a linear gain controlled VCA. This VCA is
useful for various functions such as amplitude modulation, and for gating
signals into the other wave multipliers.
The middle Wave Multiplier provides a sweep of the odd harmonics
(1, 3, 5, 7, 9, 11, 13) when a triangle wave is applied to its input and the
knob is turned up or a control voltage is swept from minimum to
maximum. The effect is very similar to overblowing a wind pipe closed at
one end, and thus the module can be used to give the effect of various
wind instruments. Different input waveforms will result in widely different
combinations of harmonics. Audio signals can be applied to the VC inputs
or the second input to develop new types of modulation. This module can
be used to explore effects beyond ring modulation because there are
more varied harmonics formed than simple sum and different tones.
The bottom Wave Multiplier performs non-linear waveshaping known
as full-wave rectification. Actually, the process involves three full-wave
rectifiers which are assembled in a very refined and controllable format. Each
section doubles the frequency of a sine or triangle wave applied to its input.
Thus, sweeping the VC input of this module over its range provides a smooth
transition between even harmonics (2, 4 and 8). Many other partials are
present in the basic sound, however, and the sonorities are very rich and
varied. A notable feature of this multiplier is that the full-wave rectification
process is not accompanied by a reduction in the output amplitude. There is
no alteration of the essential level of the sound. Another feature is that
internal time constants are incorporated which add interesting dynamic
effects, depending upon the rate of the VC control. There are two inputs
which produce various types of modulation effects, but quite different from
those generated from the other two multipliers in this module. A second
output is provided which is a "squared up" version of the main output. The
signal here resembles voltage controlled pulse width modulation.
The Wave Multipliers are among the most powerful timbral modifiers
available on any analog music synthesizer. The rich varieties of inter-patch
possibilities is nearly inexhaustible, and is useful to the individual who is
willing to experiment with entirely new sounds., As a class of modules, the
Wave Multipliers provide what has too often been lacking in electric music:
a means of generating sounds as complex and dynamically variable as those
found in acoustic sound sources. Yet these are also precision modules which
respond accurately to control voltage, so they may be used to give
repeatable results in the most exacting analog or digital applications.
>
> I just tried to connect it to my Synthi Aks a few days ago, however
> the Prestopatch connector on the panel is too wide! 2 pins too wide,
> maybe it was meant for another type of EMS device. I really want it to
> work with my Synthi Aks.
> Maybe someone has a Prestopatch pin layout map somewhere?
I also count 36 pins on your connector, and I've never seen anything other than 32 pins on
a Synthi Prestopatch slot, including my own. Also, I don't know of any other EMS gear that
has such a connector. I've seen/worked with about a dozen Synthi's with the connector,
and some VCS3's without one, but I've never seen connectors with more or fewer than 32
pins.
The Prestopatch pin layout on my Synthi A MkII is:
Matrix coordinates 1 to 16, and then A to P
So the leftmost pin on the Prestopatch is "output ch 1" (the output signal of channel 1 for
feedback) and the rightmost pin is "output ch. level 2" (where the amplitude of channel 2
is controlled).
So the left half of the connector has the outputs, and the right half has the inputs on it.
Keep in mind that these inputs require attenuation, Synthi pins have 2.7K resistors in
them, so those should be somewhere in the breakout cable too.
I've made a number of cables to interface my Synthi with Serge gear and other modulars,
as well as a computer-controlled patch matrix. It all works fine, as long as you keep the
pinout in mind, make sure to not overload the Synthi's inputs (using resistors like in the
patch pins), and make a grounding connection between the two instruments.
If I were you, I would carefully open up both the Serge case and the Prestopatch connector
on the cable, to find out what the pinout is like on the Serge cable, and then try to lose
four of the pins, either by replacing the connector altogether, or by cutting them off. Of
course, if every one of those 36 pins is in use, you'll probably have to sacrifice four
connections.
Thomas
>
> regards,
>
> Simon
>
