Touch Response - Yamaha CS-50 Servicing Manual

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the output saturates in the positive side when the plus input is higher than the minus input, and in the negative side

when the plus input is lower than the minus input. In practice, ±ISV is applied as the DC supply, and the

saturation is attained at this level.

(Sawtooth wave-+ Inversive sawtooth wave)

For inverting the sawtooth wave, the OP amplifier is used as an inverting amplifier with gain 1.

(Noise wave)

The white noise generated by the noise generator is turned into the pink noise by the low pass filter. The latter is

provided as one of the modulation signals. (Refer to the section of Noise Generator.)

(EXT signal)

Besides the signals created by the synthesizer, the low frequency signal, human voice, Auto Rhythm signal, other

audio signals or any other signals may be used as the modulation signal.

lOOK

J0/25

EXO

lOOK

VOLUME

EXT preamplifier

NOTE: OP IC (NJM4558)

These modulation signals are to be fed into VCO III, VCF and VCA.

TOUCH RESPONSE

The touch response effect is obtained by detecting the DC voltage proportional to the strength with which the key

is depressed (or the depth to which the key is depressed) and using it as the control voltage. Applying this voltage

VCO, VCF and VCA, the pitch, tone and loudness are controlled in accordance with the degree of key depression.

When this voltage is applied to the level control circuit (consisting of VCA) for modulation signal from the

sub-oscillator, the depth of modulation can be controlled in accordance with the strength of depressing the key.

Keybaord

Key depressed

to the max. depth

Touch response preamplifier

NOTE: OP is !C (NJM4558)

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Cs series