Kobol Expander I question

[krainov]

Bonjour, frères français!
J'ai une question sur le processeur Kobol Expander 1 Gate. Y a-t-il quelqu'un parmi vous qui je puisse le demander? La question concerne les tensions allant au SSM2050 à partir du processeur Gate.
Désolé pour mon Google Translate français!

[krainov]

Kobol owners and profis!
Please help!
WHAT VOLTAGE DO YOU HAVE AT B IF NO GATE SIGNAL IS APLLIED TO A?
Please look at the picture attached.
Thanks in advance!

[yusynth]

Well no need to measure, just apply Ohm's law and calculate the threshold values of the input trigger OPamp... Simple calculation says that the normal threshold (rising edge) is 1.89V, and the reverse threshold (falling edge) is 1.32V. Therefore any GATE voltage above 2V suffice to operate it. It is though suitable for any voltage in the range 2V to 14.5V.

[krainov]

Thank you, Yves!

[krainov]

Just one more question Yves!
I measure 16.4 at opAmp output (no gate signal applied).
But the datasheet of SSM2050 recommends to install the 15k resistors at the GATE and TRIGGER inputs for the +15 voltages instead of 1k as it is now seen in original schematics.
http://www.digisound80.co.uk/digisound/ ... SM2050.pdf
Do I have to follow original schematics or I may replace 1k with 15k for GATE and TRIG inputs of SSM2050?

[yusynth]

Well to complete my answer the voltage at B will be 0V when A is low (OV) is applied to the input) and 12,6V or higher depending on the supply of the OPamp when A is high.
If nothing is connected at the input then B is at 12,6V or higher depending on the supply of the OPamp when A is high.

[yusynth]

Do I have to follow original schematics or I may replace 1k with 15k for GATE and TRIG inputs of SSM2050?

It should work in both cases.

[krainov]

Thanks!

[krainov]

Hello Yves! Thanks for being patient answering my questions. I'm really sorry for my obtrusiveness.
In order to clarify how the ADS works I need to understand what is happening in circuit. Would you please answer this question.
I want to understand what is the purpose of the 11th pin (SSM2050) cap of 0.1uF of value and what is going on when the highlighted switch is ON or OFF? What does these C10, Q6, Q1 and Switch to +18V infrastructure do?
Thanks!

[yusynth]

If you check the datasheet of the SSM2050 you would read that C10 is the timing capacitor, the one being charged during the ATTACK phase and discharged during the DECAY and RELEASE phases. The switch and components associated to these are to toggle the enveloppe between the ADS and the ADSR mode. The JFET just discharges completely C10 when a key is released and the switch is in ADS mode.

[krainov]

Thanks, Yves!