Synovatron cvgt MM User manual

cvgt MM User Manual
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Copyright © 2014 Synovatron Limited. All rights reserved. (Rev 0 Febr ary 2014)

cvgt MM User Manual
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Copyright © 2014 Synovatron Limited. All rights reserved. (Rev 0 Febr ary 2014)
Introduction
Thank yo for p rchasing the Synovatron cvgt MM B chla™ Translator
Mod leMod le™. This man al explains what the cvgt MM is and how it works.
The cvgt MM is a Mod leMod le format synthesizer mod le and is compatible
with the Eardrill™ Mod leMod le Model 041 Frame. The cvgt MM fits in any
one of the fo r positions within the Model 041 frame.
The cvgt MM (Control Voltage Gate Trigger Mod le Mod le) is a CV and
Gate/Trigger interface that provides a means of exchanging CV and timing
p lse control signals between a B chla 200e Series synthesizer and another
1V/octave synthesizer. The cvgt MM is available in fo r basic variants: the
3.5mm jack socketed E rorack and banana socketed Serge™, B gBrand™ and
Fenix™ variants.
Caution
Personal and equipment safety
Please ens re yo se the cvgt MM in accordance with these instr ctions
especially taking great care to connect the power cable to the Model 041
Frame. The power cable is keyed b t always do ble check!
Only fit and remove mod les with the rack power off and
disconnected from the mains electricity supply for yo r own safety.
Refer to the connection section for power cable connection instructions.
Synovatron Electronic Music cannot be held responsible for any damage or
harm caused through incorrect or unsafe use of this module. If in doubt, stop
and check. If you are still unsure of what to do then please contact
Synovatron for advice before proceeding.

cvgt MM User Manual
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Copyright © 2014 Synovatron Limited. All rights reserved. (Rev 0 Febr ary 2014)
Eurorack variant: Switchcraft™ Tini-jax™ plu and 3.5mm
jack socket incompatibility
The Eurorack variant cvgt MM, shown above, has 3.5mm jack sockets for
E rorack connections. Please be warned that connecting a Switchcraft Tini-
jax plug to a 3.5mm jack socket will damage the 3.5mm jack contacts as the
Tini-jax pl g has a larger diameter. Synovatron Electronic M sic cannot be held
responsible for any contact damage ca sed thro gh incorrect connection to
this mod le and this will invalidate yo r warranty.

cvgt MM User Manual
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Copyright © 2014 Synovatron Limited. All rights reserved. (Rev 0 Febr ary 2014)
cvgt MM Description
The cvgt MM has fo r channels; two for CV signal translation and two for
timing signal translation. These are described as follows:-
1.2V/Octave to 1V/Octave CV Translation Channel
This is a precision b ffered DC co pled atten ator with an atten ation factor
of 0.8333. It is designed to translate B chla CV inp t signals, which have a
1.2V/octave scaling, to an o tp t compatible with synthesizers with a
1V/octave scaling.
1.2v/octave in A B chla compatible 1.2V/octave CV
inp t black banana socket. The nominal inp t range is
0V to +10V.
1v/octave out A 1V/octave compatible CV o tp t.
The o tp t range is 0V to +8.333V.
Variant Info: A 3.5mm jack socket (Eurorack
compatible) is shown but depending on the variant
purchased could be a banana socket (colour coded
either blue for Serge and enix or red for BugBrand
outputs).
There is a front panel accessible 10-t rn trim pot that can be adj sted with a
small screwdriver. This is factory set to an atten ation of 0.8333 exactly. It is
for very fine t ning only and can only adj st over a small range.
External CV to Buchla CV Translation Channel
This is a precision DC co pled amplifier designed to translate nipolar and
bipolar inp t signals from external synthesizers into the B chla 0V to +10V
inp t range.
These inp ts co ld, for example, be from a bipolar LFO (±5V), a nipolar ADSR
(0-8V), a nipolar q antizer (0-5V) etc. The scale and offset switches, in
conj nction with the –v LED, are sed to keep the o tp t to the B chla within
the 0V to +10V range.

cvgt MM User Manual
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Copyright © 2014 Synovatron Limited. All rights reserved. (Rev 0 Febr ary 2014)
ext cv in The CV inp t from an external
synthesizer.
Variant Info: A 3.5mm jack socket (Eurorack
compatible) is shown but depending on the
variant purchased could be a banana socket
(colour coded either blue for Serge and
BugBrand or black for enix inputs).
CV out A B chla compatible CV o tp t bl e
banana socket. The o tp t range is 0V to +10V.
scale This switch allows the gain to be changed to match the scale factor
or voltage range of the synthesizer signal connected to ext cv in. This can be
set for 1V/octave, 1.2V/octave and 2V/octave scales; in the 1 position the
amplifier has a gain of 1 ( nity), in the 1.2 position it has a gain of 1.2 and in
the 2 position it has a gain of 2.
offset This switch provides an o tp t offset that is added to the scaled
inp t signal of either 0V (0v) or +5V (+v). In the 0v position no offset is added
so a positive going inp t signal (e.g. envelope) will keep the o tp t positive
going.
–v LED indicator lights if the o tp t signal goes negative to warn that the
signal is o tside the sef l range of 0V to +10V for the B chla synthesizer.
The simplified schematics (a) to (f) explain in simple arithmetic terms what
inp t ranges are req ired to translate to an o tp t range of 0V to +10V sing
the vario s offset and scale switch positions.
Schematics (a) to (c) show the offset switch in the 0v position for each of the
three scale positions. Schematics (d) to (f) show the offset switch in the +v
position for each of the three scale positions.
There is a front panel accessible trim pot that can be adj sted with a small
screwdriver. This is factory set to a gain of 1.200 exactly (for the 1.2 scale). It
is for very fine t ning only and can only adj st over a small range.

cvgt MM User Manual
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Copyright © 2014 Synovatron Limited. All rights reserved. (Rev 0 Febr ary 2014)

cvgt MM User Manual
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Copyright © 2014 Synovatron Limited. All rights reserved. (Rev 0 Febr ary 2014)
B chla P lse to Gate Trigger Translator Channel
This channel is specifically designed to convert the tri-state timing p lse o tp t
from B chla 225e and 222e synthesizer mod les into 10V gate and trigger
signals that are compatible with other formats. It will also work with any signal
that exceeds the inp t thresholds of either the gate or trigger detectors as
follows:-
pulse in An orange banana socket inp t
compatible with B chla p lse o tp ts in the
range of 0V to +15V.
gate out A 0V to 10V o tp t. The o tp t
goes high (+10V) when the pulse in voltage is
above +2.7V. This is intended to follow the
gate or s stain part of B chla 225e and 222e
mod le p lses altho gh any signal exceeding
+2.7V will ca se this o tp t to go high. Refer
to the example timing diagram below. The LED
ill minates when gate out is high.
Variant Info: A 3.5mm jack socket (Eurorack compatible) is shown but
depending on the variant purchased could be a banana socket (colour coded
either red for Serge and BugBrand or blue for enix outputs).
trig out A 0V to 10V o tp t. The o tp t goes high (+10V) when the pulse
in voltage is above +7.7V. This is intended to follow the initial trigger part of
B chla 225e and 222e mod le p lses altho gh any signal exceeding +7.7V will
ca se this o tp t to go high.
Variant Info: A 3.5mm jack socket (Eurorack compatible) is shown but
depending on the variant purchased could be a banana socket (colour coded
either red for Serge and BugBrand or blue for enix outputs).
Note that trig out does not shorten pulses it just transmits the high
level pulses at the width presented to pulse in which are all narrow
pulses on Buchla synth pulse outputs. Refer to the example timing
diagram on the next page.

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Copyright © 2014 Synovatron Limited. All rights reserved. (Rev 0 Febr ary 2014)
(a) (b) (c) (d)
The timing diagram above shows fo r example pulse in inp t waveforms and
the gate out and trig out responses. The inp t switching thresholds for the
gate and trigger level detectors are shown at +2.7V and +7.7V.
The first example (a) shows the p lse shape similar to that of a B chla 225e
and 222e mod le p lses; an initial trigger p lse followed by a s stain level
which is reflected in the gate out and trig out responses.
Examples (b), (c) and (d) show that p lses are j st passed thro gh (at +10V) to
gate out and trig out if they exceed the respective thresholds. A signal that
exceeds both thresholds will be present on both o tp ts.

cvgt MM User Manual
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Copyright © 2014 Synovatron Limited. All rights reserved. (Rev 0 Febr ary 2014)
Gate Trigger to B chla P lse Translator Channel
This channel is specifically designed to convert gate and trigger signals into a
timing p lse o tp t compatible with B chla synthesizer p lse inp ts.
trig in An inp t that when the signal
applied exceeds the inp t threshold of
+3.2V will generate a +10V narrow p lse
(trimmer adj stable in the range 0.5ms to
5ms; factory set to 1ms) at pulse out
irrespective of the inp t p lse width.
Variant Info: A 3.5mm jack socket
(Eurorack compatible) is shown but
depending on the variant purchased could
be a banana socket (colour coded either
red for Serge, black for enix or blue for
BugBrand inputs).
gate in An inp t that when the signal applied exceeds the inp t threshold
of +3.2V will generate an o tp t at pulse out that is compatible with B chla™
225e and 222e mod le p lses i.e. it will ca se a tri-state o tp t p lse. The
gate in leading edge will generate a +10V narrow trigger p lse (also trimmer
adj stable in the range 0.5ms to 5ms; factory set to 4ms) at pulse out
irrespective of the inp t p lse width. It will also generate a +5V s staining
‘gate’ signal for the d ration of the inp t p lse if it extends beyond the narrow
trigger p lse. This can be seen in example (a) in the timing diagram on the next
page.
Variant Info: A 3.5mm jack socket (Eurorack compatible) is shown but
depending on the variant purchased could be a banana socket (colour coded
either red for Serge, black for enix or blue for BugBrand inputs).
pulse out A banana socket o tp t compatible with B chla synthesizer p lse
inp ts. It o tp ts a composite (an OR f nction) of the signals derived from the
trig in and gate in p lse generators. The o tp t has a diode in its path so it
can simply be connected to other B chla compatible p lses witho t signal
contention. The LED ill minates when pulse out is high.

cvgt MM User Manual
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Copyright © 2014 Synovatron Limited. All rights reserved. (Rev 0 Febr ary 2014)
(a) (b) (c) (d)
The timing diagram above shows fo r examples of gate in and trig in inp t
waveforms and the pulse out responses. The inp t switching thresholds for
the gate and trigger level detectors are shown at +3.2V.
The first example (a) shows how a B chla 225e and 222e mod le compatible
p lse is generated in response to a gate in signal; an initial 4ms trigger p lse
followed by a s stain level lasting the length of the gate in signal.
Example (b) shows what happens when the gate in signal is short and j st
generates the initial 4ms trigger p lse witho t a s staining level.
Example (c) shows what happens when the trig in signal is applied; the o tp t
is a 1ms trigger p lse triggered off the leading edge of the trig in signal and
ignores the remainder of the trig in signal d ration.
Example (d) shows what happens when a combination of gate in and trig in
signals are present.