What is a CV/GATE?

Paul Morris

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May 7, 1996, 3:00:00 AM5/7/96

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Hello

All I have ever used are digital synths so I have no idea what a CV or a
GATE is. I gather they are exclusive to analogs? Or maybe not? What
exactly do these terms refer to?

Thanks for any reply

Bouvard Hosticka

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May 8, 1996, 3:00:00 AM5/8/96

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CV = Conrol Voltage. unless otherwise specified ussually
refering to the voltage that defines the pitch of the
instrument. Most synthesizers used 1 volt per octave control
voltages but a few used theur own system. Control voltages are
also produced by envelopes, LFO's ramps ect and can be used to
modulate other things but this meaning is usually reserved to
the traditional patch-cord synthesizers.

Gate = key down (or other signal that tells the synth to make a
sound). The gate usually also triggers the envelopes (attack
when gate opens and release when gate closes)

A MIDI to CV/Gate converter will thus generate a gate between
NOTE ON and NOTE OFF messages and a CV that indicates what the
note is played. Also some can generate additional control
voltages based upon CONTROLLERS, PITCH BEND, or AFTERTOUCH.

Sometimes they are combined so that whenever ANY VOLTAGE is
present the gate is produced (or interprted)

regards,
--
Bouvard Hosticka
804 982 5440
b...@Virginia.edu

Paul Ward

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May 8, 1996, 3:00:00 AM5/8/96

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Grossly over-simplified short answer :) -
'CV' is 'Control Voltage'. In its most basic form this tells an analogue
synth which note to play. The higher the voltage, the higher the note.

'Gate' is a voltage that tells an analogue synth *when* to play. If the
gate voltage is present then the synth makes a noise - when the gate
voltage disappears the synth stops making a noise.

So the CV carries pitch information and the gate triggers the note.

Hope this helps...

--
Paul Ward: pa...@ssurreal.demon.co.uk
'An Eagle for an Emperor... A Kestrel for a Knave.'

Soundwave [Chad Gould]

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May 9, 1996, 3:00:00 AM5/9/96

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Paul Morris (pmo...@finearts.uvic.ca) wrote:
: Hello

: All I have ever used are digital synths so I have no idea what a CV or a
: GATE is. I gather they are exclusive to analogs? Or maybe not? What
: exactly do these terms refer to?

CV = Control Voltage, with most synths being 1V per octave (ie, increase
a volt = increase an octave)
Gate = An electric pulse that determines when a key is pressed (when on,
pressed, when not, it isn't)

Correct any errors...

--
Chad Gould aka Soundwave (not Gently) |--X5/D50/DX27/1202/Juno106/GUS--|
internet: cgo...@gate.net (ISDN #1134) |"Dirty pool old man, I like it!"|
Scanning and web author services avail. |Make Happy the Harmonica Happy!!|
http://www.webcom.com/cgould/ - MST3K,MIDI,pinball,ambient/emusic,andmore
SAVE MST3K!! - http://fermi.clas.virginia.edu/~jcp9j/canceled.html forinfo

Anthony John Vuolo

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May 9, 1996, 3:00:00 AM5/9/96

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>You're right that these are analog terms. CV means control voltage - most
>analog synths used a 1 volt per octave standard, so your typical keyboard
>would contain a ladder of switches and resistors so that semitones
>produced increments of 1/12 of a volt. A five octave keyboard would
>generate a control voltage of between 0 and 5 volts.
>
>The gate is a voltage generated when a key is pressed.

I have a Crumar DS-1 Mono Synth from 1980. It has the ladder of switches and
resistors liek you describe to generate the voltages.

The problem is that the voltages being generated are not correct.
The individuals keys are out of tune. Some more than others.

Does these mean the the values of the resistors haev drifted after 16 years?
and if so, would replacing them solve the problem?

Thanks ! :)

tony

David Peck

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May 10, 1996, 3:00:00 AM5/10/96

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drte...@alpha1.csd.uwm.edu (Anthony John Vuolo) wrote:

>I have a Crumar DS-1 Mono Synth from 1980. It has the ladder of switches and
>resistors liek you describe to generate the voltages.

>The problem is that the voltages being generated are not correct.
>The individuals keys are out of tune. Some more than others.

>Does these mean the the values of the resistors haev drifted after 16 years?
>and if so, would replacing them solve the problem?

>Thanks ! :)

>tony

It may be a problem with the keyboard voltage (this could be a more
major problem), but it may just be a problem with the oscillator
calibration (not as bad). Oscillators must be calibrated for
volt-per-octave, and linearity. This can be checked a few ways. Do
both oscillators track the same? (do they stay in tune with each other
as you play up and down the keyboard?) If they do, it's probably a
problem with the output voltage from the keyboard. If they don't stay
in tune with each other as you play up and down the keyboard, it's
probably just the oscillator(s) that needs calibrating. It's not hard
to do it yourself, but it's not possible for me to explain it here. If
you don't know how to do it, a repair shop should be able to calibrate
your oscillators for a small fee.

Dave Peck
da...@alr.com