Synovatron Cvgt mm User manual

cvgt MM User Manual

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cvgt MM User Manual

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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.

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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.

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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.

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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.

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cvgt MM User Manual

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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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(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.

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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.

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(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.

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Fitting Instructions

The cvgt MM can fit in any one of the fo r positions available in the

Mod leMod le Model 041 frame. The power connection from the cvgt MM is

a keyed 9-way Molex socket that pl gs into the Model 041 frame’s distrib tion

board.

The cvgt MM only ses ±15V and GndQ (0V); the other 6 pins are not

connected.

Please ens re the power is off and connect the cvgt MM power connector to

the Model 041 frame. Do ble check that the connector has been pl gged in

correctly; it is keyed to prevent misconnection so it sho ld be straightforward.

Fit the two 4-40 UNC screws s pplied to fix the cvgt MM into the Model 041

frame (nylon washers are also s pplied).

Only fit and remove mod les with the synthesizer power off and

disconnected from the mains electricity supply for yo r own safety.

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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Adjustments

The cvgt MM is adj sted d ring man fact ring tests and it sho ld not be

necessary to adj st it nless a repair has been carried o t. These adj stments

sho ld only be performed by a s itably experienced person. The CV offset and

scale adj stments req ire a precision settable/adj stable DC voltage so rce

and a precision Digital M lti-Meter (DMM) with a basic acc racy of better than

±0.1%; preferably ±0.01%. The p lse timing adj stments sho ld be performed

with the aid of a clock or repeating gate so rce (e.g. LFO set to ro ghly 10Hz),

an oscilloscope. A small screwdriver or trim tool is req ired.

CV scale adj stments are accessible via holes in the front panel. Offset and

p lse width adj stments are accessible only from the rear of the mod le as

shown below.

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1.2V/Octave to 1V/Octave CV scale adjustment procedure

(1) Meas re 1v/oct out with a DMM and with no inp t

connected to 1.2v/oct in - record the val e of the resid al

offset voltage reading.

(2) Apply 6.000V to 1.2v/oct in (this sho ld be checked

with the DMM).

(3) Meas re 1v/oct out with a DMM and adj st the pot

for a reading of 5.000V greater than the val e recorded in

step 1.

External CV to Buchla CV adjustment procedure

(1) Set the scale switch to 1.2 and the offset

switch to 0v.

(2) Meas re cv out with a DMM and with no inp t

connected to ext cv in - record the val e of the

resid al offset voltage reading.

(3) Apply 8.333V to ext cv in (this sho ld be

checked with the DMM).

(4) Meas re cv out with a DMM and adj st the

scale adj stment pot for a reading of 10.000V greater than the val e recorded

in step 2.

(5) Disconnect the voltage applied to ext cv in.

(6) Set the offset switch to +v.

(7) Meas re cv out with a DMM and adj st the offset adj stment pot RV3, at

the rear of the mod le, for 5.000V greater than the val e recorded in step 2.

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Note there is only one scale adjustment pot for the ext cv in channel so

the adjustment is optimised for a scale of 1.2. However due to the high

precision components used the other scale positions will track the 1.2

setting to within 0.1%.

Pulse width timin adjustment procedure

as shown below.

The p lse widths prod ced at pulse out in response to gate in and trig in

inp ts are factory set to a 4ms (RV2) for a gate in leading p lse and 1ms (RV1)

for a trig in p lse. These can however be set anywhere from 0.5ms to over 5ms

as req ired. The trig and gate p lse width timing adj stment pots RV1 and RV2

are on the rear of the mod le.

(1) Connect a clock so rce, e.g. an LFO, set to ro ghly 10Hz to trig in. Yo

sho ld see the LED flashing.

(2) Connect an oscilloscope to pulse out.

(3) Adj st RV2 for the desired p lse width of the 10V trigger p lse at pulse out

in response to trig in.

(4) Move the clock so rce to gate in.

(5) Adj st RV1 for the desired p lse width of the 10V leading p lse, not the 5V

gate portion, at pulse out in response to gate in.

This completes the adj stments

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cvgt MM Specification

1.2V/Octave to 1V/Octave CV Translation Channel

Input: 4mm banana socket 1.2v/oct in

Input range: 0V to +10V

Input impedance: 1MΩ

Bandwidth: DC-19kHz (-3db)

Attenuation: 0.833 ±0.1% max

Output: 3.5mm jack 1v/oct out

Output range: 0V to +8.333V

Output impedance: <1Ω

External CV to Buchla CV Translation Channel

Input: 3.5mm jack ext cv in

Input range: ±10V

Input impedance: 1MΩ

Bandwidth: DC-19kHz (-3db)

Gain: 1.000 (1), 1.200 (1.2), 2.000 (2) ±0.1% max

Output: 4mm banana socket cv out

Output impedance: <1Ω

Output range: 0V to +10V

Output indication: Red LED for negative o tp ts -v

Buchla Pulse to Gate Tri er Translator Channel

Input: 4mm banana socket pulse in

Input impedance: 100kΩ

Input threshold: +2.7V (gate), +7.5V (trigger)

Gate output: 3.5mm jack gate out

Gate output level: gate off 0V, gate on +10V

Trigger output: 3.5mm jack trig out

Trigger output level: trigger off 0V, trigger on +10V

Output indication: Red LED is on for d ration of pulse in

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Gate Tri er to Buchla Pulse Translator Channel

Gate input: 3.5mm jack gate in

Gate input impedance: 100kΩ

Gate input threshold: +3.2V

Trigger input: 3.5mm jack trig in

Trigger input impedance: 100kΩ

Trigger input threshold: +3.2V

Output: 4mm banana socket pulse out

Output level:

• Gate initiated: gate off 0V, gate on +10V initially (0.5ms to 5ms) falling

to +5V for d ration of gate in. The leading edge of the gate in signal

initiates the timer. The p lse d ration (0.5ms to 5ms) is set by a trimmer

(factory set to 4ms).

• Trigger initiated: trigger off 0V, trigger on +10V (0.5ms to 5ms) initiated

by trig in. The leading edge of the trig in signal initiates the timer. The

p lse d ration (0.5ms to 5ms) is set by a trimmer.

• Pulse output: The gate and trigger initiated signals are OR’ed together

sing diodes. This allows other mod les with diode connected o tp ts

to also be OR’d with this signal.

Output indication: Red LED is on for the d ration of pulse out

Please note that Synovatron reserves the right to change the specification without notice.

General

Dimensions

107.8mm x 38.5mm (4.24” x 1.51”)

Power consumption

±15V @ 25mA

Contents

cvgt MM Mod le, 2 x 4-40 Phillips screws and 2 x nylon washers

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Environmental

All components sed on the cvgt MM Mod le are RoHS compliant. To comply

with the WEEE Directive please do not discard into landfill – please recycle all

Waste Electrical and Electronic Eq ipment responsibly – please contact

Synovatron to ret rn the cvgt MM Mod le for disposal if req ired.

Warranty

The cvgt MM Mod le is g aranteed against defective parts and workmanship

for 12 months from date of p rchase. Note that any physical or electrical

damage d e to mis se or incorrect connection invalidates the warranty. A low

cost repair service will be available for any repairs o tside of warranty

conditions.

Quality

The cvgt MM Mod le is a high q ality professional analog e device that was

lovingly and caref lly designed, b ilt, tested in the United Kingdom by

Synovatron Electronic M sic. Please be ass red of my commitment to

providing good reliable and sable eq ipment! Any s ggestions for

improvements will be gratef lly received.

Thank yo and happy m sic making.

Tony.

Contact details

Tony Steventon

Synovatron Electronic M sic

104 Twyford Aven e

Portsmo th

PO2 8DJ

UK

M: +44 (0) 7889 053435

T: +44 (0) 2392 669339

E: Synovatron@btinternet.com

W: http://synovatron.blogspot.com

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Synovatron cvgt MM User manual

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